InVivoMAb anti-mouse CD8α
Product Details
The YTS 169.4 monoclonal antibody reacts with mouse CD8α. The CD8 antigen is a transmembrane glycoprotein that acts as a co-receptor for the T cell receptor (TCR). Like the TCR, CD8 binds to class I MHC molecules displayed by antigen presenting cells (APC). CD8 is primarily expressed on the surface of cytotoxic T cells, but can also be found on thymocytes, natural killer cells, and some dendritic cell subsets. CD8 most commonly exists as a heterodimer composed of one CD8α and one CD8β chain however, it can also exist as a homodimer composed of two CD8α chains. Both the CD8α and CD8β chains share significant homology to immunoglobulin variable light chains. The molecular weight of each CD8 chain is approximately 34 kDa. The YTS 169.4 antibody exhibits depleting activity when used in vivo.Specifications
| Isotype | Rat IgG2b, κ |
|---|---|
| Recommended Isotype Control(s) | InVivoMAb rat IgG2b isotype control, anti-keyhole limpet hemocyanin |
| Recommended Dilution Buffer | InVivoPure pH 7.0 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Immunogen | CBA mouse thymocytes |
| Reported Applications |
in vivo CD8+ T cell depletion Western blot |
| Formulation |
PBS, pH 7.0 Contains no stabilizers or preservatives |
| Endotoxin |
<2EU/mg (<0.002EU/μg) Determined by LAL gel clotting assay |
| Purity |
>95% Determined by SDS-PAGE |
| Sterility | 0.2 µm filtration |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G |
| RRID | AB_10950145 |
| Molecular Weight | 150 kDa |
| Storage | The antibody solution should be stored at the stock concentration at 4°C. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Isotype Control(s)
InVivoMAb rat IgG2b isotype control, anti-keyhole limpet hemocyanin
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Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
in vivo CD8+ T cell depletion
Vashist, N., et al. (2018). "Influenza-Activated ILC1s Contribute to Antiviral Immunity Partially Influenced by Differential GITR Expression" Front Immunol 9: 505. PubMed
Innate lymphoid cells (ILCs) represent diversified subsets of effector cells as well as immune regulators of mucosal immunity and are classified into group 1 ILCs, group 2 ILCs, and group 3 ILCs. Group 1 ILCs encompass natural killer (NK) cells and non-NK ILCs (ILC1s) and mediate their functionality via the rapid production of IFN-gamma and TNF-alpha. The current knowledge of ILC1s mainly associates them to inflammatory processes. Much less is known about their regulation during infection and their capacity to interact with cells of the adaptive immune system. The present study dissected the role of ILC1s during early influenza A virus infection, thereby revealing their impact on the antiviral response. Exploiting in vitro and in vivo H1N1 infection systems, a cross-talk of ILC1s with cells of the innate and the adaptive immunity was demonstrated, which contributes to anti-influenza immunity. A novel association of ILC1 functionality and the expression of the glucocorticoid-induced TNFR-related protein (GITR) was observed, which hints toward a so far undescribed role of GITR in regulating ILC1 responsiveness. Overexpression of GITR inhibits IFN-gamma production by ILC1s, whereas partial reduction of GITR expression can reverse this effect, thereby regulating ILC1 functionality. These new insights into ILC1 biology define potential intervention targets to modulate the functional properties of ILC1s, thus contributing toward the development of new immune interventions against influenza.
in vivo CD8+ T cell depletion
Triplett, T. A., et al. (2018). "Reversal of indoleamine 2,3-dioxygenase-mediated cancer immune suppression by systemic kynurenine depletion with a therapeutic enzyme" Nat Biotechnol 36(8): 758-764. PubMed
Increased tryptophan (Trp) catabolism in the tumor microenvironment (TME) can mediate immune suppression by upregulation of interferon (IFN)-gamma-inducible indoleamine 2,3-dioxygenase (IDO1) and/or ectopic expression of the predominantly liver-restricted enzyme tryptophan 2,3-dioxygenase (TDO). Whether these effects are due to Trp depletion in the TME or mediated by the accumulation of the IDO1 and/or TDO (hereafter referred to as IDO1/TDO) product kynurenine (Kyn) remains controversial. Here we show that administration of a pharmacologically optimized enzyme (PEGylated kynureninase; hereafter referred to as PEG-KYNase) that degrades Kyn into immunologically inert, nontoxic and readily cleared metabolites inhibits tumor growth. Enzyme treatment was associated with a marked increase in the tumor infiltration and proliferation of polyfunctional CD8(+) lymphocytes. We show that PEG-KYNase administration had substantial therapeutic effects when combined with approved checkpoint inhibitors or with a cancer vaccine for the treatment of large B16-F10 melanoma, 4T1 breast carcinoma or CT26 colon carcinoma tumors. PEG-KYNase mediated prolonged depletion of Kyn in the TME and reversed the modulatory effects of IDO1/TDO upregulation in the TME.
in vivo CD8+ T cell depletion
Carmi, Y., et al. (2015). "Allogeneic IgG combined with dendritic cell stimuli induce antitumour T-cell immunity" Nature 521(7550): 99-104. PubMed
Whereas cancers grow within host tissues and evade host immunity through immune-editing and immunosuppression, tumours are rarely transmissible between individuals. Much like transplanted allogeneic organs, allogeneic tumours are reliably rejected by host T cells, even when the tumour and host share the same major histocompatibility complex alleles, the most potent determinants of transplant rejection. How such tumour-eradicating immunity is initiated remains unknown, although elucidating this process could provide the basis for inducing similar responses against naturally arising tumours. Here we find that allogeneic tumour rejection is initiated in mice by naturally occurring tumour-binding IgG antibodies, which enable dendritic cells (DCs) to internalize tumour antigens and subsequently activate tumour-reactive T cells. We exploited this mechanism to treat autologous and autochthonous tumours successfully. Either systemic administration of DCs loaded with allogeneic-IgG-coated tumour cells or intratumoral injection of allogeneic IgG in combination with DC stimuli induced potent T-cell-mediated antitumour immune responses, resulting in tumour eradication in mouse models of melanoma, pancreas, lung and breast cancer. Moreover, this strategy led to eradication of distant tumours and metastases, as well as the injected primary tumours. To assess the clinical relevance of these findings, we studied antibodies and cells from patients with lung cancer. T cells from these patients responded vigorously to autologous tumour antigens after culture with allogeneic-IgG-loaded DCs, recapitulating our findings in mice. These results reveal that tumour-binding allogeneic IgG can induce powerful antitumour immunity that can be exploited for cancer immunotherapy.
in vivo CD8+ T cell depletion
Burrack, K. S., et al. (2015). "Myeloid Cell Arg1 Inhibits Control of Arthritogenic Alphavirus Infection by Suppressing Antiviral T Cells" PLoS Pathog 11(10): e1005191. PubMed
Arthritogenic alphaviruses, including Ross River virus (RRV) and chikungunya virus (CHIKV), are responsible for explosive epidemics involving millions of cases. These mosquito-transmitted viruses cause inflammation and injury in skeletal muscle and joint tissues that results in debilitating pain. We previously showed that arginase 1 (Arg1) was highly expressed in myeloid cells in the infected and inflamed musculoskeletal tissues of RRV- and CHIKV-infected mice, and specific deletion of Arg1 from myeloid cells resulted in enhanced viral control. Here, we show that Arg1, along with other genes associated with suppressive myeloid cells, is induced in PBMCs isolated from CHIKV-infected patients during the acute phase as well as the chronic phase, and that high Arg1 expression levels were associated with high viral loads and disease severity. Depletion of both CD4 and CD8 T cells from RRV-infected Arg1-deficient mice restored viral loads to levels detected in T cell-depleted wild-type mice. Moreover, Arg1-expressing myeloid cells inhibited virus-specific T cells in the inflamed and infected musculoskeletal tissues, but not lymphoid tissues, following RRV infection in mice, including suppression of interferon-gamma and CD69 expression. Collectively, these data enhance our understanding of the immune response following arthritogenic alphavirus infection and suggest that immunosuppressive myeloid cells may contribute to the duration or severity of these debilitating infections.
in vivo CD8+ T cell depletion
Wensveen, F. M., et al. (2015). "NK cells link obesity-induced adipose stress to inflammation and insulin resistance" Nat Immunol 16(4): 376-385. PubMed
An important cause of obesity-induced insulin resistance is chronic systemic inflammation originating in visceral adipose tissue (VAT). VAT inflammation is associated with the accumulation of proinflammatory macrophages in adipose tissue, but the immunological signals that trigger their accumulation remain unknown. We found that a phenotypically distinct population of tissue-resident natural killer (NK) cells represented a crucial link between obesity-induced adipose stress and VAT inflammation. Obesity drove the upregulation of ligands of the NK cell-activating receptor NCR1 on adipocytes; this stimulated NK cell proliferation and interferon-gamma (IFN-gamma) production, which in turn triggered the differentiation of proinflammatory macrophages and promoted insulin resistance. Deficiency of NK cells, NCR1 or IFN-gamma prevented the accumulation of proinflammatory macrophages in VAT and greatly ameliorated insulin sensitivity. Thus NK cells are key regulators of macrophage polarization and insulin resistance in response to obesity-induced adipocyte stress.
in vivo CD8+ T cell depletion
Li, Z., et al. (2015). "Pre-treatment of allogeneic bone marrow recipients with the CXCR4 antagonist AMD3100 transiently enhances hematopoietic chimerism without promoting donor-specific skin allograft tolerance" Transpl Immunol 33(2): 125-129. PubMed
Hematopoietic chimerism established by allogeneic bone marrow transplantation is known to promote donor-specific organ allograft tolerance; however, clinical application is limited by the need for toxic host conditioning and “megadoses” of donor bone marrow cells. A potential solution to this problem has been suggested by the observation that recipient bone marrow mobilization by the CXCR4 antagonist AMD3100 promotes chimerism in congenic bone marrow transplantation experiments in mice. Here we report that a single subcutaneous dose of 10mg/kg AMD3100 in recipient C57BL/6 mice was able to enhance hematopoietic chimerism when complete MHC-mismatched BALB/c donor bone marrow cells were transplanted 1h after drug dosing. However, levels of chimerism measured 30days post-transplantation were not sustained when mice were reexamined on day 90 post-transplantation. Moreover, transient chimerism induced by this protocol did not support robust donor-specific skin allograft tolerance. Using the same transient immunosuppression protocol, we confirmed that “megadoses” of donor bone marrow cells could induce durable chimerism associated with donor-specific skin allograft tolerance without AMD3100 pre-treatment. We conclude that in this protocol AMD3100 pretreatment may empty bone marrow niches that become reoccupied by allogeneic donor hematopoietic progenitor cells but not by true long-lived donor hematopoietic stem cells, resulting in short-lived chimerism and failure to support durable donor-specific allograft tolerance.
in vivo CD8+ T cell depletion
Krupnick, A. S., et al. (2014). "Central memory CD8+ T lymphocytes mediate lung allograft acceptance" J Clin Invest 124(3): 1130-1143. PubMed
Memory T lymphocytes are commonly viewed as a major barrier for long-term survival of organ allografts and are thought to accelerate rejection responses due to their rapid infiltration into allografts, low threshold for activation, and ability to produce inflammatory mediators. Because memory T cells are usually associated with rejection, preclinical protocols have been developed to target this population in transplant recipients. Here, using a murine model, we found that costimulatory blockade-mediated lung allograft acceptance depended on the rapid infiltration of the graft by central memory CD8+ T cells (CD44(hi)CD62L(hi)CCR7+). Chemokine receptor signaling and alloantigen recognition were required for trafficking of these memory T cells to lung allografts. Intravital 2-photon imaging revealed that CCR7 expression on CD8+ T cells was critical for formation of stable synapses with antigen-presenting cells, resulting in IFN-gamma production, which induced NO and downregulated alloimmune responses. Thus, we describe a critical role for CD8+ central memory T cells in lung allograft acceptance and highlight the need for tailored approaches for tolerance induction in the lung.
in vivo CD8+ T cell depletion
Pastille, E., et al. (2014). "Transient ablation of regulatory T cells improves antitumor immunity in colitis-associated colon cancer" Cancer Res 74(16): 4258-4269. PubMed
Regulatory T cells (Treg) are supportive to cancer development in most tissues, but their role in colitis-associated colon cancer (CAC) remains unclear. In this study, we investigated the role of CD4(+)Foxp3(+) Treg in a mouse model of CAC and in patients with colon cancer. These Treg were increased strongly in number in a mouse model of CAC and in the peripheral blood of patients with colon cancer, exhibiting an activated phenotype as defined by elevated expression of GARP, CD103, CTLA-4, and IL10, along with an increased suppressive effect on the proliferation and Th1 cytokine expression of CD4(+)CD25(-) responder T cells ex vivo. Transient ablation of CD4(+)Foxp3(+) Treg during tumor development in the CAC model suppressed tumor outgrowth and distribution, accompanied by an increased number of CD8(+)IFNgamma/granzyme B-producing effector T cells. Conversely, inactivation of IL10 in Treg did not elevate the antitumor response but instead further boosted tumor development. Our results establish a tumor-promoting function for Treg during CAC formation, but they also suggest that a selective, transient ablation of Treg can evoke antitumor responses, with implications for immunotherapeutic interventions in patients with CAC.
in vivo CD8+ T cell depletion
Bivas-Benita, M., et al. (2013). "Airway CD8(+) T cells induced by pulmonary DNA immunization mediate protective anti-viral immunity" Mucosal Immunol 6(1): 156-166. PubMed
Vaccination strategies for protection against a number of respiratory pathogens must induce T-cell populations in both the pulmonary airways and peripheral lymphoid organs. In this study, we show that pulmonary immunization using plasmid DNA formulated with the polymer polyethyleneimine (PEI-DNA) induced antigen-specific CD8(+) T cells in the airways that persisted long after antigen local clearance. The persistence of the cells was not mediated by local lymphocyte proliferation or persistent antigen presentation within the lung or airways. These vaccine-induced CD8(+) T cells effectively mediated protective immunity against respiratory challenges with vaccinia virus and influenza virus. Moreover, this protection was not dependent upon the recruitment of T cells from peripheral sites. These findings demonstrate that pulmonary immunization with PEI-DNA is an efficient approach for inducing robust pulmonary CD8(+) T-cell populations that are effective at protecting against respiratory pathogens.
in vivo CD8+ T cell depletion
Dai, M., et al. (2013). "Long-lasting complete regression of established mouse tumors by counteracting Th2 inflammation" J Immunother 36(4): 248-257. PubMed
40% of mice with SW1 tumors remained healthy >150 days after last treatment and are probably cured. Therapeutic efficacy was associated with a systemic immune response with memory and antigen specificity, required CD4 cells and involved CD8 cells and NK cells to a less extent. The 3 mAb combination significantly decreased CD19 cells at tumor sites, increased IFN-gamma and TNF-alpha producing CD4 and CD8 T cells and mature CD86 dendritic cells (DC), and it increased the ratios of effector CD4 and CD8 T cells to CD4Foxp3 regulatory T (Treg) cells and to CD11bGr-1 myeloid suppressor cells (MDSC). This is consistent with shifting the tumor microenvironment from an immunosuppressive Th2 to an immunostimulatory Th1 type and is further supported by PCR data. Adding an anti-CD19 mAb to the 3 mAb combination in the SW1 model further increased therapeutic efficacy. Data from ongoing experiments show that intratumoral injection of a combination of mAbs to CD137PD-1CTLA4CD19 can induce complete regression and dramatically prolong survival also in the TC1 carcinoma and B16 melanoma models, suggesting that the approach has general validity.”}” data-sheets-userformat=”{“2″:14851,”3”:{“1″:0},”4”:{“1″:2,”2″:16777215},”12″:0,”14”:{“1″:2,”2″:1521491},”15″:”Roboto, sans-serif”,”16″:12}”>Mice with intraperitoneal ID8 ovarian carcinoma or subcutaneous SW1 melanoma were injected with monoclonal antibodies (mAbs) to CD137PD-1CTLA4 7-15 days after tumor initiation. Survival of mice with ID8 tumors tripled and >40% of mice with SW1 tumors remained healthy >150 days after last treatment and are probably cured. Therapeutic efficacy was associated with a systemic immune response with memory and antigen specificity, required CD4 cells and involved CD8 cells and NK cells to a less extent. The 3 mAb combination significantly decreased CD19 cells at tumor sites, increased IFN-gamma and TNF-alpha producing CD4 and CD8 T cells and mature CD86 dendritic cells (DC), and it increased the ratios of effector CD4 and CD8 T cells to CD4Foxp3 regulatory T (Treg) cells and to CD11bGr-1 myeloid suppressor cells (MDSC). This is consistent with shifting the tumor microenvironment from an immunosuppressive Th2 to an immunostimulatory Th1 type and is further supported by PCR data. Adding an anti-CD19 mAb to the 3 mAb combination in the SW1 model further increased therapeutic efficacy. Data from ongoing experiments show that intratumoral injection of a combination of mAbs to CD137PD-1CTLA4CD19 can induce complete regression and dramatically prolong survival also in the TC1 carcinoma and B16 melanoma models, suggesting that the approach has general validity.
in vivo CD8+ T cell depletion
Sledzinska, A., et al. (2013). "TGF-beta signalling is required for CD4(+) T cell homeostasis but dispensable for regulatory T cell function" PLoS Biol 11(10): e1001674. PubMed
TGF-beta is widely held to be critical for the maintenance and function of regulatory T (T(reg)) cells and thus peripheral tolerance. This is highlighted by constitutive ablation of TGF-beta receptor (TR) during thymic development in mice, which leads to a lethal autoimmune syndrome. Here we describe that TGF-beta-driven peripheral tolerance is not regulated by TGF-beta signalling on mature CD4(+) T cells. Inducible TR2 ablation specifically on CD4(+) T cells did not result in a lethal autoinflammation. Transfer of these TR2-deficient CD4(+) T cells to lymphopenic recipients resulted in colitis, but not overt autoimmunity. In contrast, thymic ablation of TR2 in combination with lymphopenia led to lethal multi-organ inflammation. Interestingly, deletion of TR2 on mature CD4(+) T cells does not result in the collapse of the T(reg) cell population as observed in constitutive models. Instead, a pronounced enlargement of both regulatory and effector memory T cell pools was observed. This expansion is cell-intrinsic and seems to be caused by increased T cell receptor sensitivity independently of common gamma chain-dependent cytokine signals. The expression of Foxp3 and other regulatory T cells markers was not dependent on TGF-beta signalling and the TR2-deficient T(reg) cells retained their suppressive function both in vitro and in vivo. In summary, absence of TGF-beta signalling on mature CD4(+) T cells is not responsible for breakdown of peripheral tolerance, but rather controls homeostasis of mature T cells in adult mice.
in vivo CD8+ T cell depletion
Krieg, C., et al. (2010). "Improved IL-2 immunotherapy by selective stimulation of IL-2 receptors on lymphocytes and endothelial cells" Proc Natl Acad Sci U S A 107(26): 11906-11911. PubMed
IL-2 immunotherapy is an attractive treatment option for certain metastatic cancers. However, administration of IL-2 to patients can lead, by ill-defined mechanisms, to toxic adverse effects including severe pulmonary edema. Here, we show that IL-2-induced pulmonary edema is caused by direct interaction of IL-2 with functional IL-2 receptors (IL-2R) on lung endothelial cells in vivo. Treatment of mice with high-dose IL-2 led to efficient expansion of effector immune cells expressing high levels of IL-2Rbetagamma, including CD8(+) T cells and natural killer cells, which resulted in a considerable antitumor response against s.c. and pulmonary B16 melanoma nodules. However, high-dose IL-2 treatment also affected immune cell lineage marker-negative CD31(+) pulmonary endothelial cells via binding to functional alphabetagamma IL-2Rs, expressed at low to intermediate levels on these cells, thus causing pulmonary edema. Notably, IL-2-mediated pulmonary edema was abrogated by a blocking antibody to IL-2Ralpha (CD25), genetic disruption of CD25, or the use of IL-2Rbetagamma-directed IL-2/anti-IL-2 antibody complexes, thereby interfering with IL-2 binding to IL-2Ralphabetagamma(+) pulmonary endothelial cells. Moreover, IL-2/anti-IL-2 antibody complexes led to vigorous activation of IL-2Rbetagamma(+) effector immune cells, which generated a dramatic antitumor response. Thus, IL-2/anti-IL-2 antibody complexes might improve current strategies of IL-2-based tumor immunotherapy.
in vivo CD8+ T cell depletion
Shariff, H., et al. (2010). "Intermittent antibody-based combination therapy removes alloantibodies and achieves indefinite heart transplant survival in presensitized recipients" Transplantation 90(3): 270-278. PubMed
BACKGROUND: It is well established that primed/memory T cells play a critical role in heart transplant rejection. This contributes to the challenges faced in the transplant clinic because current treatments that are efficient in controlling naive T cell alloresponses have limited efficacy on primed T cell responders. METHODS: Fully MHC-mismatched heart transplantation was performed from BALB/c to C57BL/6 mice presensitized with BALB/c splenocytes 14 days pretransplantation. A combination therapy comprising CD70-, CD154-, and CD8-specific antibodies (Abs) was administered at day 0 and 4 posttransplantation with rapamycin on days 0 to 4. RESULTS: The Ab combination therapy extended heart transplant survival in presensitized recipients from median survival time 8 days (MST) to MST 78 days. A decrease in the number of splenic interferon-gamma-secreting cells measured by ELISpot assay was seen in the treated group compared with the untreated controls. However, graft-infiltrating CD8+ and CD4+ T cells persisted despite treatment and the number of intragraft CD4+ T cells increased at day 30 posttransplantation. When an additional “rescue therapy” comprising the same Abs was readministered at days 30, 60, and 90 posttransplantation, T cell infiltration was reduced and indefinite graft survival was observed. Furthermore, rescue therapy resulted in gradual decrease in titer and, by day 90 posttransplantation, the complete loss of the preexisting, donor-specific Abs. CONCLUSION: We conclude that our Ab combination therapy extends allograft survival in presensitized recipients. When combined with intermittent Ab-mediated rescue therapy, this results in indefinite allograft survival and a loss of the preexisting, donor-specific Abs from the circulation.
in vivo CD8+ T cell depletion
Kish, D. D., et al. (2009). "CD8 T cells producing IL-17 and IFN-gamma initiate the innate immune response required for responses to antigen skin challenge" J Immunol 182(10): 5949-5959. PubMed
Effector CD8 T cell recruitment into the skin in response to Ag challenge requires prior CXCL1/KC-directed neutrophil infiltration. Mechanisms inducing CXCL1 production and the dynamics of neutrophil-CD8 T cell interactions during elicitation of Ag-specific responses in the skin were investigated. CXCL1 and CXCL2/MIP-2 were produced within 3-6 h of Ag challenge at 10-fold higher levels in skin challenge sites of Ag-sensitized vs nonsensitized mice. In the challenge sites of sensitized mice this production decreased at 6-9 h postchallenge to near the levels observed in skin challenge sites of nonsensitized mice but rose to a second peak 12 h after challenge. The elevated early neutrophil chemoattractant production at 3-6 h after skin challenge of sensitized animals required both IFN-gamma and IL-17, produced by distinct populations of Ag-primed CD8 T cells in response to Ag challenge. Although induced by the Ag-primed CD8 T cells, the early CXCL1 and CXCL2 production was accompanied by neutrophil but not CD8 T cell infiltration into the skin Ag challenge site. Infiltration of the CD8 T cells into the challenge site was not observed until 18-24 h after challenge. These results demonstrate an intricate series of early interactions between Ag-specific and innate immune components that regulate the sequential infiltration of neutrophils and then effector T cells into the skin to mediate an immune response.
- Mus musculus (House mouse),
High-titer AAV disrupts cerebrovascular integrity and induces lymphocyte infiltration in adult mouse brain.
In Molecular Therapy. Methods Clinical Development on 14 December 2023 by Guo, Y., Chen, J., et al.
PubMed
The brain is often described as an "immune-privileged" organ due to the presence of the blood-brain-barrier (BBB), which limits the entry of immune cells. In general, intracranial injection of adeno-associated virus (AAV) is considered a relatively safe procedure. In this study, we discovered that AAV, a popular engineered viral vector for gene therapy, can disrupt the BBB and induce immune cell infiltration in a titer-dependent manner. First, our bulk RNA sequencing data revealed that injection of high-titer AAV significantly upregulated many genes involved in disrupting BBB integrity and antiviral adaptive immune responses. By using histologic analysis, we further demonstrated that the biological structure of the BBB was severely disrupted in the adult mouse brain. Meanwhile, we noticed abnormal leakage of blood components, including immune cells, within the brain parenchyma of high-titer AAV injected areas. Moreover, we identified that the majority of infiltrated immune cells were cytotoxic T lymphocytes (CTLs), which resulted in a massive loss of neurons at the site of AAV injection. In addition, antagonizing CTL function by administering antibodies significantly reduced neuronal toxicity induced by high-titer AAV. Collectively, our findings underscore potential severe side effects of intracranial injection of high-titer AAV, which might compromise proper data interpretation if unaware of. © 2023 The Authors.
- Mus musculus (House mouse),
- Biochemistry and Molecular biology,
- Cancer Research,
- Cell Biology,
- Immunology and Microbiology
Fibrinogen-like protein 2 promotes tumor immune suppression by regulating cholesterol metabolism in myeloid-derived suppressor cells.
In Journal for Immunotherapy of Cancer on 6 December 2023 by Wu, L., Liu, X., et al.
PubMed
Myeloid-derived suppressor cells (MDSCs) are crucial mediators of tumor-associated immune suppression. Targeting the accumulation and activation of MDSCs has been recognized as a promising approach to enhance the effectiveness of immunotherapies for different types of cancer. The MC38 and B16 tumor-bearing mouse models were established to investigate the role of Fgl2 during tumor progression. Fgl2 and FcγRIIB-deficient mice, adoptive cell transfer, RNA-sequencing and flow cytometry analysis were used to assess the role of Fgl2 on immunosuppressive activity and differentiation of MDSCs. Here, we show that fibrinogen-like protein 2 (Fgl2) regulates the differentiation and immunosuppressive functions of MDSCs. The absence of Fgl2 leads to an increase in antitumor CD8+ T-cell responses and a decrease in granulocytic MDSC accumulation. The regulation mechanism involves Fgl2 modulating cholesterol metabolism, which promotes the accumulation of MDSCs and immunosuppression through the production of reactive oxygen species and activation of XBP1 signaling. Inhibition of Fgl2 or cholesterol metabolism in MDSCs reduces their immunosuppressive activity and enhances differentiation. Targeting Fgl2 could potentially enhance the therapeutic efficacy of anti-PD-1 antibody in immunotherapy. These results suggest that Fgl2 plays a role in promoting immune suppression by modulating cholesterol metabolism and targeting Fgl2 combined with PD-1 checkpoint blockade provides a promising therapeutic strategy for antitumor therapy. © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
Differential requirements for CD4+ T cells in the efficacy of the anti-PD-1+LAG-3 and anti-PD-1+CTLA-4 combinations in melanoma flank and brain metastasis models.
In Journal for Immunotherapy of Cancer on 6 December 2023 by Phadke, M. S., Li, J., et al.
PubMed
Although the anti-PD-1+LAG-3 and the anti-PD-1+CTLA-4 combinations are effective in advanced melanoma, it remains unclear whether their mechanisms of action overlap. We used single cell (sc) RNA-seq, flow cytometry and IHC analysis of responding SM1, D4M-UV2 and B16 melanoma flank tumors and SM1 brain metastases to explore the mechanism of action of the anti-PD-1+LAG-3 and the anti-PD-1+CTLA-4 combination. CD4+ and CD8+ T cell depletion, tetramer binding assays and ELISPOT assays were used to demonstrate the unique role of CD4+T cell help in the antitumor effects of the anti-PD-1+LAG-3 combination. The anti-PD-1+CTLA-4 combination was associated with the infiltration of FOXP3+regulatory CD4+ cells (Tregs), fewer activated CD4+T cells and the accumulation of a subset of IFNγ secreting cytotoxic CD8+T cells, whereas the anti-PD-1+LAG-3 combination led to the accumulation of CD4+T helper cells that expressed CXCR4, TNFSF8, IL21R and a subset of CD8+T cells with reduced expression of cytotoxic markers. T cell depletion studies showed a requirement for CD4+T cells for the anti-PD-1+LAG-3 combination, but not the PD-1-CTLA-4 combination at both flank and brain tumor sites. In anti-PD-1+LAG-3 treated tumors, CD4+T cell depletion was associated with fewer activated (CD69+) CD8+T cells and impaired IFNγ release but, conversely, increased numbers of activated CD8+T cells and IFNγ release in anti-PD-1+CTLA-4 treated tumors. Together these studies suggest that these two clinically relevant immune checkpoint inhibitor (ICI) combinations have differential effects on CD4+T cell polarization, which in turn, impacted cytotoxic CD8+T cell function. Further insights into the mechanisms of action/resistance of these clinically-relevant ICI combinations will allow therapy to be further personalized. © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
A2AR eGFP reporter mouse enables elucidation of A2AR expression dynamics during anti-tumor immune responses.
In Nature Communications on 1 November 2023 by Todd, K. L., Lai, J., et al.
PubMed
There is significant clinical interest in targeting adenosine-mediated immunosuppression, with several small molecule inhibitors having been developed for targeting the A2AR receptor. Understanding of the mechanism by which A2AR is regulated has been hindered by difficulty in identifying the cell types that express A2AR due to a lack of robust antibodies for these receptors. To overcome this limitation, here an A2AR eGFP reporter mouse is developed, enabling the expression of A2AR during ongoing anti-tumor immune responses to be assessed. This reveals that A2AR is highly expressed on all tumor-infiltrating lymphocyte subsets including Natural Killer (NK) cells, NKT cells, γδ T cells, conventional CD4+ and CD8+ T lymphocytes and on a MHCIIhiCD86hi subset of type 2 conventional dendritic cells. In response to PD-L1 blockade, the emergence of PD-1+A2AR- cells correlates with successful therapeutic responses, whilst IL-18 is identified as a cytokine that potently upregulates A2AR and synergizes with A2AR deficiency to improve anti-tumor immunity. These studies provide insight into the biology of A2AR in the context of anti-tumor immunity and reveals potential combination immunotherapy approaches. © 2023. The Author(s).
- Biochemistry and Molecular biology,
- Cancer Research,
- Genetics,
- Immunology and Microbiology
Spleen-targeted neoantigen DNA vaccine for personalized immunotherapy of hepatocellular carcinoma.
In EMBO Molecular Medicine on 11 October 2023 by Wu, M., Luo, Z., et al.
PubMed
Neoantigens are emerging as attractive targets to develop personalized cancer vaccines, but their immunization efficacy is severely hampered by their restricted accessibility to lymphoid tissues where immune responses are initiated. Leveraging the capability of red blood cells (RBCs) to capture and present pathogens in peripheral blood to the antigen-presenting cells (APCs) in spleen, we developed a RBC-driven spleen targeting strategy to deliver DNA vaccine encoding hepatocellular carcinoma (HCC) neoantigen. The DNA vaccine-encapsulating polymeric nanoparticles that were intentionally hitchhiked on the preisolated RBCs could preferentially accumulate in the spleen to promote the neoantigen expression by APCs, resulting in the burst of neoantigen-specific T-cell immunity to prevent tumorigenesis in a personalized manner, and slow down tumor growth in the established aggressively growing HCC. Remarkably, when combined with anti-PD-1, the vaccine achieved complete tumor regression and generated a robust systemic immune response with long-term tumor-specific immunological memory, which thoroughly prevented tumor recurrence and spontaneous lung metastasis. This study offers a prospective strategy to develop personalized neoantigen vaccines for augmenting cancer immunotherapy efficiency in immune "cold" HCC. © 2023 The Authors. Published under the terms of the CC BY 4.0 license.
- Immunology and Microbiology,
- Neuroscience
Inhibition of adult hippocampal neurogenesis induced by postoperative CD8 + T-cell infiltration is associated with cognitive decline later following surgery in adult mice.
In Journal of Neuroinflammation on 5 October 2023 by Li, X., Wang, H., et al.
PubMed
Some patients show persistent cognitive decline for weeks, months or even years after surgery, which seriously affects their long-term prognosis and quality of life. However, most previous basic studies have focused mainly on the mechanisms of early postoperative cognitive decline, whereas cognitive decline in the longer term after surgery is less well-understood. The subgranular zone of the dentate gyrus exhibits life-long neurogenesis, supporting hippocampus-dependent learning and memory. The aim of this study was to investigate whether adult hippocampal neurogenesis (AHN) involves in cognitive decline later following surgery and to further explore the roles of CD8 + T lymphocytes infiltrating the hippocampal parenchyma after surgery in this pathological process. Cognitive function was examined in adult mice that underwent laparotomy combined with partial hepatectomy, and the results showed that cognitive decline persisted in mice who underwent surgery during the first postoperative month, even though there was a trend toward continuous improvement over time. Significantly decreased numbers of DCX + cells, BrdU + cells, and BrdU + /DCX + cells were observed on day 8 after surgery, and a significantly decreased number of NeuN + /BrdU + cells was observed on day 28 after surgery, which indicated inhibition of AHN. After surgery, T lymphocytes, the majority of which were CD8 + T cells, infiltrated the hippocampus and secreted Interferon-γ (IFN-γ). Depletion of CD8 + T cells could inhibit the increase of IFN-γ synthesis, improve hippocampal neurogenesis, and improve postoperative cognitive function. Hippocampal microinjection of IFN-γ neutralizing antibody or adeno-associated virus to knock down IFN-γ receptor 1 (IFNGR1) could also partially attenuate the inhibition of AHN and improve postoperative cognitive function. These results demonstrate that postoperative infiltration of CD8 + T cells into the hippocampus and subsequent secretion of IFN-γ contribute to the inhibition of AHN and cognitive decline later following surgery. © 2023. BioMed Central Ltd., part of Springer Nature.
- Mus musculus (House mouse),
- Immunology and Microbiology
Coxsackievirus B3 elicits a sex-specific CD8+ T cell response which protects female mice.
In PLoS Pathogens on 1 September 2023 by Dhalech, A. H., Condotta, S. A., et al.
PubMed
Sex is a significant contributor to the outcome of human infections. Males are frequently more susceptible to viral, bacterial, and fungal infections, often attributed to weaker immune responses. In contrast, a heightened immune response in females enables better pathogen elimination but leaves females more predisposed to autoimmune diseases. Unfortunately, the underlying basis for sex-specific immune responses remains poorly understood. Here, we show a sex difference in the CD8+ T cell response to an enteric virus, Coxsackievirus B3 (CVB3). We found that CVB3 induced expansion of CD8+ T cells in female mice but not in male mice. CVB3 also increased the proportion and number of CD11ahiCD62Llo CD8+ T cells in female mice, indicative of activation. This response was independent of the inoculation route and type I interferon. Using a recombinant CVB3 virus expressing a model CD8+ T cell epitope, we found that the expansion of CD8+ T cells in females is viral-specific and not due to bystander activation. Finally, the depletion of CD8+ T cells, prior to infection, led to enhanced mortality, indicating that CD8+ T cells are protective against CVB3 in female mice. These data demonstrate that CVB3 induces a CD8+ T cell response in female mice and highlight the importance of sex-specific immune responses to viral pathogens. Copyright: © 2023 Dhalech et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
- Cancer Research,
- Immunology and Microbiology,
- Mus musculus (House mouse)
Combined PARP and WEE1 inhibition triggers anti-tumor immune response in BRCA1/2 wildtype triple-negative breast cancer.
In NPJ Breast Cancer on 15 August 2023 by Teo, Z. L., O'Connor, L. O., et al.
PubMed
Novel therapeutic strategies that can effectively combine with immunotherapies are needed in the treatment of triple-negative breast cancer (TNBC). We demonstrate that combined PARP and WEE1 inhibition are synergistic in controlling tumour growth in BRCA1/2 wild-type TNBC preclinical models. The PARP inhibitor (PARPi) olaparib combined with the WEE1 inhibitor (WEE1i) adavosertib triggered increases in anti-tumour immune responses, including STING pathway activation. Combinations with a STING agonist resulted in further improved durable tumour regression and significant improvements in survival outcomes in murine tumour models of BRCA1/2 wild-type TNBC. In addition, we have identified baseline tumour-infiltrating lymphocyte (TIL) levels as a potential predictive biomarker of response to PARPi, WEE1i and immunotherapies in BRCA1/2 wild-type TNBC. © 2023. Springer Nature Limited.
- Immunology and Microbiology
CD39 inhibition and VISTA blockade may overcome radiotherapy resistance by targeting exhausted CD8+ T cells and immunosuppressive myeloid cells.
In Cell Reports Medicine on 15 August 2023 by Zhang, Y., Hu, J., et al.
PubMed
Although radiotherapy (RT) has achieved great success in the treatment of non-small cell lung cancer (NSCLC), local relapses still occur and abscopal effects are rarely seen even when it is combined with immune checkpoint blockers (ICBs). Here, we characterize the dynamic changes of tumor-infiltrating immune cells after RT in a therapy-resistant murine tumor model using single-cell transcriptomes and T cell receptor sequencing. At the early stage, the innate and adaptive immune systems are activated. At the late stage, however, the tumor immune microenvironment (TIME) shifts into immunosuppressive properties. Our study reveals that inhibition of CD39 combined with RT preferentially decreases the percentage of exhausted CD8+ T cells. Moreover, we find that the combination of V-domain immunoglobulin suppressor of T cell activation (VISTA) blockade and RT synergistically reduces immunosuppressive myeloid cells. Clinically, high VISTA expression is associated with poor prognosis in patients with NSCLC. Altogether, our data provide deep insight into acquired resistance to RT from an immune perspective and present rational combination strategies. Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.
- Immunology and Microbiology,
- Cancer Research
The GPCR-Gαs-PKA signaling axis promotes T cell dysfunction and cancer immunotherapy failure.
In Nature Immunology on 1 August 2023 by Wu, V. H., Yung, B. S., et al.
PubMed
Immune checkpoint blockade (ICB) targeting PD-1 and CTLA-4 has revolutionized cancer treatment. However, many cancers do not respond to ICB, prompting the search for additional strategies to achieve durable responses. G-protein-coupled receptors (GPCRs) are the most intensively studied drug targets but are underexplored in immuno-oncology. Here, we cross-integrated large singe-cell RNA-sequencing datasets from CD8+ T cells covering 19 distinct cancer types and identified an enrichment of Gαs-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, β1AR and β2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted Gαs-DREADD to activate CD8-restricted Gαs signaling and show that a Gαs-PKA signaling axis promotes CD8+ T cell dysfunction and immunotherapy failure. These data indicate that Gαs-GPCRs are druggable immune checkpoints that might be targeted to enhance the response to ICB immunotherapies. © 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.
- Cancer Research
Profiling of syngeneic mouse HCC tumor models as a framework to understand anti-PD-1 sensitive tumor microenvironments.
In Hepatology on 1 May 2023 by Zabransky, D. J., Danilova, L., et al.
PubMed
The treatment of hepatocellular carcinoma (HCC) has been transformed by the use of immune checkpoint inhibitors. However, most patients with HCC do not benefit from treatment with immunotherapy. There is an urgent need to understand the mechanisms that underlie response or resistance to immunotherapy for patients with HCC. The use of syngeneic mouse models that closely recapitulate the heterogeneity of human HCC will provide opportunities to examine the complex interactions between cancer cells and nonmalignant cells in the tumor microenvironment. We leverage a multifaceted approach that includes imaging mass cytometry and suspension cytometry by time of flight to profile the tumor microenvironments of the Hep53.4, Hepa 1-6, RIL-175, and TIBx (derivative of TIB-75) syngeneic mouse HCC models. The immune tumor microenvironments vary across these four models, and various immunosuppressive pathways exist at baseline in orthotopic liver tumors derived from these models. For instance, TIBx, which is resistant to anti-programmed cell death protein 1 therapy, contains a high proportion of "M2-like" tumor-associated macrophages with the potential to diminish antitumor immunity. Investigation of The Cancer Genome Atlas reveals that the baseline immunologic profiles of Hep53.4, RIL-175, and TIBx are broadly representative of human HCCs; however, Hepa 1-6 does not recapitulate the immune tumor microenvironment of the vast majority of human HCCs. There is a wide diversity in the immune tumor microenvironments in preclinical models and in human HCC, highlighting the need to use multiple syngeneic HCC models to improve the understanding of how to treat HCC through immune modulation. Copyright © 2023 American Association for the Study of Liver Diseases.
- FC/FACS,
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Targeting DCLK1 attenuates tumor stemness and evokes antitumor immunity in triple-negative breast cancer by inhibiting IL-6/STAT3 signaling.
In Breast Cancer Research : BCR on 17 April 2023 by Liu, H., Yan, R., et al.
PubMed
Triple-negative breast cancer (TNBC) exhibits the poorest outcomes among breast cancer subtypes due to the high heterogeneity and a lasting scarcity of effectual treatments. Targeted therapies based on molecular subtypes of TNBC are critical step toward tailoring treatments to improve clinical outcomes. Gastrointestinal cancer stem cell (CSC) marker DCLK1 was reported to be highly expressed in stem cell-rich subtype of TNBC. Here, we firstly explored the impacts of DCLK1 on tumor cells as well as their immune microenvironment in TNBC and potential therapeutic strategies for TNBC patients with high DCLK1 expression. Our results disclosed that DCLK1 overexpression promoted, while knockout of DCLK1 suppressed the CSC-like traits of TNBC cells and resistance to chemotherapeutics. Besides, DCLK1 supported immune escape by inhibiting intratumoral cytotoxic T cell infiltration in TNBC and hence limited immune checkpoint inhibitors efficacy. Mechanistically, bioinformatics analysis revealed that IL-6/STAT3 signaling was significantly enriched in high DCLK1-expressing patients, and our results further revealed that DCLK1 enhanced IL-6 expression and STAT3 activation in TNBC cells, which finally gave rise to upregulated CSC traits and suppressed CD8+ T-cell activity. Inhibiting IL-6/STAT3 pathway by IL-6R antagonist, Tocilizumab or STAT3 inhibitor, S31-201 could abolish DCLK1-promoted malignant phenotypes of TNBC cells. Finally, DCLK1 was identified to be specifically and highly expressed in the mesenchymal-like subtype of TNBC and targeting DCLK1 could improve chemotherapy efficacy and activate antitumor immunity. Overall, our study revealed the potential clinical benefits of targeting DCLK1 in TNBC treatment. © 2023. The Author(s).
- In Vivo,
- Mus musculus (House mouse),
- Cancer Research
Targeting the mevalonate pathway suppresses ARID1A-inactivated cancers by promoting pyroptosis.
In Cancer Cell on 10 April 2023 by Zhou, W., Liu, H., et al.
PubMed
ARID1A, encoding a subunit of the SWI/SNF complex, is mutated in ∼50% of clear cell ovarian carcinoma (OCCC) cases. Here we show that inhibition of the mevalonate pathway synergizes with immune checkpoint blockade (ICB) by driving inflammasome-regulated immunomodulating pyroptosis in ARID1A-inactivated OCCCs. SWI/SNF inactivation downregulates the rate-limiting enzymes in the mevalonate pathway such as HMGCR and HMGCS1, which creates a dependence on the residual activity of the pathway in ARID1A-inactivated cells. Inhibitors of the mevalonate pathway such as simvastatin suppresses the growth of ARID1A mutant, but not wild-type, OCCCs. In addition, simvastatin synergizes with anti-PD-L1 antibody in a genetic OCCC mouse model driven by conditional Arid1a inactivation and in a humanized immunocompetent ARID1A mutant patient-derived OCCC mouse model. Our data indicate that inhibition of the mevalonate pathway simultaneously suppresses tumor cell growth and boosts antitumor immunity by promoting pyroptosis, which synergizes with ICB in suppressing ARID1A-mutated cancers. Copyright © 2023 Elsevier Inc. All rights reserved.
- Immunology and Microbiology,
- Neuroscience,
- Mus musculus (House mouse)
Temporal tracking of microglial and monocyte single-cell transcriptomics in lethal flavivirus infection.
In Acta Neuropathologica Communications on 4 April 2023 by Spiteri, A. G., Wishart, C. L., et al.
PubMed
As the resident parenchymal myeloid population in the central nervous system (CNS), microglia are strategically positioned to respond to neurotropic virus invasion and have been implicated in promoting both disease resolution and progression in the acute and post-infectious phase of virus encephalitis. In a mouse model of West Nile virus encephalitis (WNE), infection of the CNS results in recruitment of large numbers of peripheral immune cells into the brain, the majority being nitric oxide (NO)-producing Ly6Chi inflammatory monocyte-derived cells (MCs). In this model, these cells enhance immunopathology and mortality. However, the contribution of microglia to this response is currently undefined. Here we used a combination of experimental tools, including single-cell RNA sequencing (scRNA-seq), microglia and MC depletion reagents, high-dimensional spectral cytometry and computational algorithms to dissect the differential contribution of microglia and MCs to the anti-viral immune response in severe neuroinflammation seen in WNE. Intriguingly, analysis of scRNA-seq data revealed 6 unique microglia and 3 unique MC clusters that were predominantly timepoint-specific, demonstrating substantial transcriptional adaptation with disease progression over the course of WNE. While microglia and MC adopted unique gene expression profiles, gene ontology enrichment analysis, coupled with microglia and MC depletion studies, demonstrated a role for both of these cells in the trafficking of peripheral immune cells into the CNS, T cell responses and viral clearance. Over the course of infection, microglia transitioned from a homeostatic to an anti-viral and then into an immune cell-recruiting phenotype. Conversely, MC adopted antigen-presenting, immune cell-recruiting and NO-producing phenotypes, which all had anti-viral function. Overall, this study defines for the first time the single-cell transcriptomic responses of microglia and MCs over the course of WNE, demonstrating both protective and pathological roles of these cells that could potentially be targeted for differential therapeutic intervention to dampen immune-mediated pathology, while maintaining viral clearance functions. © 2023. The Author(s).
- Immunology and Microbiology
Vector Aided Microenvironment programming (VAMP): reprogramming the TME with MVA virus expressing IL-12 for effective antitumor activity.
In Journal for Immunotherapy of Cancer on 1 April 2023 by Seclì, L., Infante, L., et al.
PubMed
Tumor microenvironment (TME) represents a critical hurdle in cancer immunotherapy, given its ability to suppress antitumor immunity. Several efforts are made to overcome this hostile TME with the development of new therapeutic strategies modifying TME to boost antitumor immunity. Among these, cytokine-based approaches have been pursued for their known immunomodulatory effects on different cell populations within the TME. IL-12 is a potent pro-inflammatory cytokine that demonstrates striking immune activation and tumor control but causes severe adverse effects when systemically administered. Thus, local administration is considered a potential strategy to achieve high cytokine concentrations at the tumor site while sparing systemic adverse effects. Modified Vaccinia Ankara (MVA) vector is a potent inducer of pro-inflammatory response. Here, we cloned IL-12 into the genome of MVA for intratumoral immunotherapy, combining the immunomodulatory properties of both the vector and the cargo. The antitumor activity of MVA-IL-12 and its effect on TME reprogramming were investigated in preclinical tumor models. RNA sequencing (RNA-Seq) analysis was performed to assess changes in the TME in treated and distal tumors and the effect on the intratumoral T-cell receptor repertoire. Intratumoral injection of MVA-IL-12 resulted in strong antitumor activity with the complete remission of established tumors in multiple murine models, including those resistant to checkpoint inhibitors. The therapeutic activity of MVA-IL-12 was associated with very low levels of circulating cytokine. Effective TME reprogramming was demonstrated on treatment, with the reduction of immunosuppressive M2 macrophages while increasing pro-inflammatory M1, and recruitment of dendritic cells. TME switch from immunosuppressive into immunostimulatory environment allowed for CD8 T cells priming and expansion leading to tumor attack. Intratumoral administration of MVA-IL-12 turns immunologically 'cold' tumors 'hot' and overcomes resistance to programmed cell death protein-1 blockade. © Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
SIRT7 orchestrates melanoma progression by simultaneously promoting cell survival and immune evasion via UPR activation.
In Signal Transduction and Targeted Therapy on 15 March 2023 by Yi, X., Wang, H., et al.
PubMed
Melanoma is the most lethal type of skin cancer, originating from the malignant transformation of melanocyte. While the development of targeted therapy and immunotherapy has gained revolutionary advances in potentiating the therapeutic effect, the prognosis of patients with melanoma is still suboptimal. During tumor progression, melanoma frequently encounters stress from both endogenous and exogenous sources in tumor microenvironment. SIRT7 is a nuclear-localized deacetylase of which the activity is highly dependent on intracellular nicotinamide adenine dinucleotide (NAD+), with versatile biological functions in maintaining cell homeostasis. Nevertheless, whether SIRT7 regulates tumor cell biology and tumor immunology in melanoma under stressful tumor microenvironment remains elusive. Herein, we reported that SIRT7 orchestrates melanoma progression by simultaneously promoting tumor cell survival and immune evasion via the activation of unfolded protein response. We first identified that SIRT7 expression was the most significantly increased one in sirtuins family upon stress. Then, we proved that the deficiency of SIRT7 potentiated tumor cell death under stress in vitro and suppressed melanoma growth in vivo. Mechanistically, SIRT7 selectively activated the IRE1α-XBP1 axis to potentiate the pro-survival ERK signal pathway and the secretion of tumor-promoting cytokines. SIRT7 directly de-acetylated SMAD4 to antagonize the TGF-β-SMAD4 signal, which relieved the transcriptional repression on IRE1α and induced the activation of the IRE1α-XBP1 axis. Moreover, SIRT7 up-regulation eradicated anti-tumor immunity by promoting PD-L1 expression via the IRE1α-XBP1 axis. Additionally, the synergized therapeutic effect of SIRT7 suppression and anti-PD-1 immune checkpoint blockade was also investigated. Taken together, SIRT7 can be employed as a promising target to restrain tumor growth and increase the effect of melanoma immunotherapy. © 2023. The Author(s).
- Cancer Research,
- Immunology and Microbiology
Polymerase θ inhibition activates the cGAS-STING pathway and cooperates with immune checkpoint blockade in models of BRCA-deficient cancer.
In Nature Communications on 13 March 2023 by Patterson-Fortin, J., Jadhav, H., et al.
PubMed
Recently developed inhibitors of polymerase theta (POLθ) have demonstrated synthetic lethality in BRCA-deficient tumor models. To examine the contribution of the immune microenvironment to antitumor efficacy, we characterized the effects of POLθ inhibition in immunocompetent models of BRCA1-deficient triple-negative breast cancer (TNBC) or BRCA2-deficient pancreatic ductal adenocarcinoma (PDAC). We demonstrate that genetic POLQ depletion or pharmacological POLθ inhibition induces both innate and adaptive immune responses in these models. POLθ inhibition resulted in increased micronuclei, cGAS/STING pathway activation, type I interferon gene expression, CD8+ T cell infiltration and activation, local paracrine activation of dendritic cells and upregulation of PD-L1 expression. Depletion of CD8+ T cells compromised the efficacy of POLθ inhibition, whereas antitumor effects were augmented in combination with anti-PD-1 immunotherapy. Collectively, our findings demonstrate that POLθ inhibition induces immune responses in a cGAS/STING-dependent manner and provide a rationale for combining POLθ inhibition with immune checkpoint blockade for the treatment of HR-deficient cancers. © 2023. The Author(s).
- Cancer Research,
- Immunology and Microbiology
mTORC1 upregulates B7-H3/CD276 to inhibit antitumor T cells and drive tumor immune evasion.
In Nature Communications on 3 March 2023 by Liu, H. J., Du, H., et al.
PubMed
Identifying the mechanisms underlying the regulation of immune checkpoint molecules and the therapeutic impact of targeting them in cancer is critical. Here we show that high expression of the immune checkpoint B7-H3 (CD276) and high mTORC1 activity correlate with immunosuppressive phenotypes and worse clinical outcomes in 11,060 TCGA human tumors. We find that mTORC1 upregulates B7-H3 expression via direct phosphorylation of the transcription factor YY2 by p70 S6 kinase. Inhibition of B7-H3 suppresses mTORC1-hyperactive tumor growth via an immune-mediated mechanism involving increased T-cell activity and IFN-γ responses coupled with increased tumor cell expression of MHC-II. CITE-seq reveals strikingly increased cytotoxic CD38+CD39+CD4+ T cells in B7-H3-deficient tumors. In pan-human cancers, a high cytotoxic CD38+CD39+CD4+ T-cell gene signature correlates with better clinical prognosis. These results show that mTORC1-hyperactivity, present in many human tumors including tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis (LAM), drives B7-H3 expression leading to suppression of cytotoxic CD4+ T cells. © 2023. The Author(s).
- Cancer Research,
- Immunology and Microbiology
Intersection of immune and oncometabolic pathways drives cancer hyperprogression during immunotherapy.
In Cancer Cell on 13 February 2023 by Li, G., Choi, J. E., et al.
PubMed
Immune checkpoint blockade (ICB) can produce durable responses against cancer. We and others have found that a subset of patients experiences paradoxical rapid cancer progression during immunotherapy. It is poorly understood how tumors can accelerate their progression during ICB. In some preclinical models, ICB causes hyperprogressive disease (HPD). While immune exclusion drives resistance to ICB, counterintuitively, patients with HPD and complete response (CR) following ICB manifest comparable levels of tumor-infiltrating CD8+ T cells and interferon γ (IFNγ) gene signature. Interestingly, patients with HPD but not CR exhibit elevated tumoral fibroblast growth factor 2 (FGF2) and β-catenin signaling. In animal models, T cell-derived IFNγ promotes tumor FGF2 signaling, thereby suppressing PKM2 activity and decreasing NAD+, resulting in reduction of SIRT1-mediated β-catenin deacetylation and enhanced β-catenin acetylation, consequently reprograming tumor stemness. Targeting the IFNγ-PKM2-β-catenin axis prevents HPD in preclinical models. Thus, the crosstalk of core immunogenic, metabolic, and oncogenic pathways via the IFNγ-PKM2-β-catenin cascade underlies ICB-associated HPD. Copyright © 2022 Elsevier Inc. All rights reserved.
- Cancer Research,
- Immunology and Microbiology
Natural killer cells suppress cancer metastasis by eliminating circulating cancer cells.
In Frontiers in Immunology on 4 February 2023 by Vyas, M., Requesens, M., et al.
PubMed
Despite significant advances in cancer treatment, the metastatic spread of malignant cells to distant organs remains a major cause of cancer-related deaths. Natural killer (NK) cells play a crucial role in controlling tumor metastasis; however, the dynamics of NK cell-mediated clearance of metastatic tumors are not entirely understood. Herein, we demonstrate the cooperative role of NK and T cells in the surveillance of melanoma metastasis. We found that NK cells effectively limited the pulmonary seeding of B16 melanoma cells, while T cells played a primary role in restricting metastatic foci growth in the lungs. Although the metastatic foci in the lungs at the endpoint were largely devoid of NK cells, they played a prominent role in promoting T cell recruitment into the metastatic foci. Our data suggested that the most productive interaction between NK cells and metastatic cancer cells occurred when cancer cells were in circulation. Modifying the route of administration so that intravenously injected melanoma cells bypass the first liver passage resulted in significantly more melanoma metastasis to the lung. This finding indicated the liver as a prominent site where NK cells cleared melanoma cells to regulate their seeding in the lungs. Consistent with this notion, the liver and the lungs of the tumor-bearing mice showed dominance of NK and T cell activation, respectively. Thus, NK cells and T cells control pulmonary metastasis of melanoma cells by distinct mechanisms where NK cells play a critical function in shaping T cell-mediated in situ control of lung-seeded cancer cells. A precise understanding of the cooperative role of NK and T cells in controlling tumor metastasis will enable the development of the next generation of cancer immunotherapies. Copyright © 2023 Vyas, Requesens, Nguyen, Peigney, Azin and Demehri.
