InVivoPlus rat IgG2b isotype control, anti-keyhole limpet hemocyanin
Product Details
The LTF-2 monoclonal antibody reacts with keyhole limpet hemocyanin (KLH). Because KLH is not expressed by mammals this antibody is ideal for use as an isotype-matched control for rat IgG2b antibodies in mostĀ in vivoĀ andĀ in vitroĀ applications.Specifications
| Isotype | Rat IgG2b,Ā Īŗ |
|---|---|
| Recommended Dilution Buffer | InVivoPure pH 7.0 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Formulation |
PBS, pH 7.0 Contains no stabilizers or preservatives |
| Aggregation* |
<5% Determined by SEC |
| Purity |
>95% Determined by SDS-PAGE |
| Sterility | 0.2 Āµm filtration |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G |
| RRID | AB_1107780 |
| Molecular Weight | 150 kDa |
| Murine Pathogen Tests* |
Ectromelia/Mousepox Virus: Negative Hantavirus: Negative K Virus: Negative Lactate Dehydrogenase-Elevating Virus: Negative Lymphocytic Choriomeningitis virus: Negative Mouse Adenovirus: Negative Mouse Cytomegalovirus: Negative Mouse Hepatitis Virus: Negative Mouse Minute Virus: Negative Mouse Norovirus: Negative Mouse Parvovirus: Negative Mouse Rotavirus: Negative Mycoplasma Pulmonis: Negative Pneumonia Virus of Mice: Negative Polyoma Virus: Negative Reovirus Screen: Negative Sendai Virus: Negative Theilerās Murine Encephalomyelitis: Negative |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Dilution Buffer
InVivoPure pH 7.0 Dilution Buffer
Bauche, D., et al. (2018). "LAG3(+) Regulatory T Cells Restrain Interleukin-23-Producing CX3CR1(+) Gut-Resident Macrophages during Group 3 Innate Lymphoid Cell-Driven Colitis" Immunity 49(2): 342-352 e345. PubMed
Interleukin-22 (IL-22)-producing group 3 innate lymphoid cells (ILC3) maintains gut homeostasis but can also promote inflammatory bowel disease (IBD). The regulation of ILC3-dependent colitis remains to be elucidated. Here we show that Foxp3(+) regulatory T cells (Treg cells) prevented ILC3-mediated colitis in an IL-10-independent manner. Treg cells inhibited IL-23 and IL-1beta production from intestinal-resident CX3CR1(+) macrophages but not CD103(+) dendritic cells. Moreover, Treg cells restrained ILC3 production of IL-22 through suppression of CX3CR1(+) macrophage production of IL-23 and IL-1beta. This suppression was contact dependent and was mediated by latent activation gene-3 (LAG-3)-an immune checkpoint receptor-expressed on Treg cells. Engagement of LAG-3 on MHC class II drove profound immunosuppression of CX3CR1(+) tissue-resident macrophages. Our study reveals that the health of the intestinal mucosa is maintained by an axis driven by Treg cells communication with resident macrophages that withhold inflammatory stimuli required for ILC3 function.
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.
Aloulou, M., et al. (2016). "Follicular regulatory T cells can be specific for the immunizing antigen and derive from naive T cells" Nat Commun 7: 10579. PubMed
T follicular regulatory (Tfr) cells are a subset of Foxp3(+) regulatory T (Treg) cells that form in response to immunization or infection, which localize to the germinal centre where they control the magnitude of the response. Despite an increased interest in the role of Tfr cells in humoral immunity, many fundamental aspects of their biology remain unknown, including whether they recognize self- or foreign antigen. Here we show that Tfr cells can be specific for the immunizing antigen, irrespective of whether it is a self- or foreign antigen. We show that, in addition to developing from thymic derived Treg cells, Tfr cells can also arise from Foxp3(-) precursors in a PD-L1-dependent manner, if the adjuvant used is one that supports T-cell plasticity. These findings have important implications for Tfr cell biology and for improving vaccine efficacy by formulating vaccines that modify the Tfr:Tfh cell ratio.
Finkin, S., et al. (2015). "Ectopic lymphoid structures function as microniches for tumor progenitor cells in hepatocellular carcinoma" Nat Immunol. doi : 10.1038/ni.3290. PubMed
Ectopic lymphoid-like structures (ELSs) are often observed in cancer, yet their function is obscure. Although ELSs signify good prognosis in certain malignancies, we found that hepatic ELSs indicated poor prognosis for hepatocellular carcinoma (HCC). We studied an HCC mouse model that displayed abundant ELSs and found that they constituted immunopathological microniches wherein malignant hepatocyte progenitor cells appeared and thrived in a complex cellular and cytokine milieu until gaining self-sufficiency. The egress of progenitor cells and tumor formation were associated with the autocrine production of cytokines previously provided by the niche. ELSs developed via cooperation between the innate immune system and adaptive immune system, an event facilitated by activation of the transcription factor NF-kappaB and abolished by depletion of T cells. Such aberrant immunological foci might represent new targets for cancer therapy.
Zhang, J., et al. (2015). "Micro-RNA-155-mediated control of heme oxygenase 1 (HO-1) is required for restoring adaptively tolerant CD4+ T-cell function in rodents" Eur J Immunol 45(3): 829-842. PubMed
T cells chronically stimulated by a persistent antigen often become dysfunctional and lose effector functions and proliferative capacity. To identify the importance of micro-RNA-155 (miR-155) in this phenomenon, we analyzed mouse miR-155-deficient CD4(+) T cells in a model where the chronic exposure to a systemic antigen led to T-cell functional unresponsiveness. We found that miR-155 was required for restoring function of T cells after programmed death receptor 1 blockade. Heme oxygenase 1 (HO-1) was identified as a specific target of miR-155 and inhibition of HO-1 activity restored the expansion and tissue migration capacity of miR-155(-/-) CD4(+) T cells. Moreover, miR-155-mediated control of HO-1 expression in CD4(+) T cells was shown to sustain in vivo antigen-specific expansion and IL-2 production. Thus, our data identify HO-1 regulation as a mechanism by which miR-155 promotes T-cell-driven inflammation.
Park, H. J., et al. (2015). "PD-1 upregulated on regulatory T cells during chronic virus infection enhances the suppression of CD8+ T cell immune response via the interaction with PD-L1 expressed on CD8+ T cells" J Immunol 194(12): 5801-5811. PubMed
Regulatory T (Treg) cells act as terminators of T cell immuniy during acute phase of viral infection; however, their role and suppressive mechanism in chronic viral infection are not completely understood. In this study, we compared the phenotype and function of Treg cells during acute or chronic infection with lymphocytic choriomeningitis virus. Chronic infection, unlike acute infection, led to a large expansion of Treg cells and their upregulation of programmed death-1 (PD-1). Treg cells from chronically infected mice (chronic Treg cells) displayed greater suppressive capacity for inhibiting both CD8(+) and CD4(+) T cell proliferation and subsequent cytokine production than those from naive or acutely infected mice. A contact between Treg and CD8(+) T cells was necessary for the potent suppression of CD8(+) T cell immune response. More importantly, the suppression required cell-specific expression and interaction of PD-1 on chronic Treg cells and PD-1 ligand on CD8(+) T cells. Our study defines PD-1 upregulated on Treg cells and its interaction with PD-1 ligand on effector T cells as one cause for the potent T cell suppression and proposes the role of PD-1 on Treg cells, in addition to that on exhausted T cells, during chronic viral infection.
Twyman-Saint Victor, C., et al. (2015). "Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer" Nature 520(7547): 373-377. PubMed
Immune checkpoint inhibitors result in impressive clinical responses, but optimal results will require combination with each other and other therapies. This raises fundamental questions about mechanisms of non-redundancy and resistance. Here we report major tumour regressions in a subset of patients with metastatic melanoma treated with an anti-CTLA4 antibody (anti-CTLA4) and radiation, and reproduced this effect in mouse models. Although combined treatment improved responses in irradiated and unirradiated tumours, resistance was common. Unbiased analyses of mice revealed that resistance was due to upregulation of PD-L1 on melanoma cells and associated with T-cell exhaustion. Accordingly, optimal response in melanoma and other cancer types requires radiation, anti-CTLA4 and anti-PD-L1/PD-1. Anti-CTLA4 predominantly inhibits T-regulatory cells (Treg cells), thereby increasing the CD8 T-cell to Treg (CD8/Treg) ratio. Radiation enhances the diversity of the T-cell receptor (TCR) repertoire of intratumoral T cells. Together, anti-CTLA4 promotes expansion of T cells, while radiation shapes the TCR repertoire of the expanded peripheral clones. Addition of PD-L1 blockade reverses T-cell exhaustion to mitigate depression in the CD8/Treg ratio and further encourages oligoclonal T-cell expansion. Similarly to results from mice, patients on our clinical trial with melanoma showing high PD-L1 did not respond to radiation plus anti-CTLA4, demonstrated persistent T-cell exhaustion, and rapidly progressed. Thus, PD-L1 on melanoma cells allows tumours to escape anti-CTLA4-based therapy, and the combination of radiation, anti-CTLA4 and anti-PD-L1 promotes response and immunity through distinct mechanisms.
Rutigliano, J. A., et al. (2014). "Highly pathological influenza A virus infection is associated with augmented expression of PD-1 by functionally compromised virus-specific CD8+ T cells" J Virol 88(3): 1636-1651. PubMed
One question that continues to challenge influenza A research is why some strains of virus are so devastating compared to their more mild counterparts. We approached this question from an immunological perspective, investigating the CD8(+) T cell response in a mouse model system comparing high- and low-pathological influenza virus infections. Our findings reveal that the early (day 0 to 5) viral titer was not the determining factor in the outcome of disease. Instead, increased numbers of antigen-specific CD8(+) T cells and elevated effector function on a per-cell basis were found in the low-pathological infection and correlated with reduced illness and later-time-point (day 6 to 10) viral titer. High-pathological infection was associated with increased PD-1 expression on influenza virus-specific CD8(+) T cells, and blockade of PD-L1 in vivo led to reduced virus titers and increased CD8(+) T cell numbers in high- but not low-pathological infection, though T cell functionality was not restored. These data show that high-pathological acute influenza virus infection is associated with a dysregulated CD8(+) T cell response, which is likely caused by the more highly inflamed airway microenvironment during the early days of infection. Therapeutic approaches specifically aimed at modulating innate airway inflammation may therefore promote efficient CD8(+) T cell activity. We show that during a severe influenza virus infection, one type of immune cell, the CD8 T cell, is less abundant and less functional than in a more mild infection. This dysregulated T cell phenotype correlates with a lower rate of virus clearance in the severe infection and is partially regulated by the expression of a suppressive coreceptor called PD-1. Treatment with an antibody that blocks PD-1 improves T cell functionality and increases virus clearance.
Erickson, J. J., et al. (2014). "Programmed death-1 impairs secondary effector lung CD8(+) T cells during respiratory virus reinfection" J Immunol 193(10): 5108-5117. PubMed
Reinfections with respiratory viruses are common and cause significant clinical illness, yet precise mechanisms governing this susceptibility are ill defined. Lung Ag-specific CD8(+) T cells (T(CD8)) are impaired during acute viral lower respiratory infection by the inhibitory receptor programmed death-1 (PD-1). To determine whether PD-1 contributes to recurrent infection, we first established a model of reinfection by challenging B cell-deficient mice with human metapneumovirus (HMPV) several weeks after primary infection, and found that HMPV replicated to high titers in the lungs. A robust secondary effector lung TCD8 response was generated during reinfection, but these cells were more impaired and more highly expressed the inhibitory receptors PD-1, LAG-3, and 2B4 than primary T(CD8). In vitro blockade demonstrated that PD-1 was the dominant inhibitory receptor early after reinfection. In vivo therapeutic PD-1 blockade during HMPV reinfection restored lung T(CD8) effector functions (i.e., degranulation and cytokine production) and enhanced viral clearance. PD-1 also limited the protective efficacy of HMPV epitope-specific peptide vaccination and impaired lung T(CD8) during heterotypic influenza virus challenge infection. Our results indicate that PD-1 signaling may contribute to respiratory virus reinfection and evasion of vaccine-elicited immune responses. These results have important implications for the design of effective vaccines against respiratory viruses.
Steel, C. D., et al. (2014). "Role of peripheral immune response in microglia activation and regulation of brain chemokine and proinflammatory cytokine responses induced during VSV encephalitis" J Neuroimmunol 267(1-2): 50-60. PubMed
We report herein that neuroinvasion by vesicular stomatitis virus (VSV) activates microglia and induces a peripheral dendritic cell (DC)-dependent inflammatory response in the central nervous system (CNS). VSV neuroinvasion rapidly induces multiple brain chemokine and proinflammatory cytokine mRNAs that display bimodal kinetics. Peripheral DC ablation or T cell depletion suppresses the second wave of this response demonstrating that infiltrating T cells are primarily responsible for the bimodal characteristics of this response. The robust infiltrate associated with VSV encephalitis likely depends on sustained production of brain CCL19 and CCR7 expression on infiltrating inflammatory cells.
Kearl, T. J., et al. (2013). "Programmed death receptor-1/programmed death receptor ligand-1 blockade after transient lymphodepletion to treat myeloma" J Immunol 190(11): 5620-5628. PubMed
Early phase clinical trials targeting the programmed death receptor-1/ligand-1 (PD-1/PD-L1) pathway to overcome tumor-mediated immunosuppression have reported promising results for a variety of cancers. This pathway appears to play an important role in the failure of immune reactivity to malignant plasma cells in multiple myeloma patients, as the tumor cells express relatively high levels of PD-L1, and T cells show increased PD-1 expression. In the current study, we demonstrate that PD-1/PD-L1 blockade with a PD-L1-specific Ab elicits rejection of a murine myeloma when combined with lymphodepleting irradiation. This particular combined approach by itself has not previously been shown to be efficacious in other tumor models. The antitumor effect of lymphodepletion/anti-PD-L1 therapy was most robust when tumor Ag-experienced T cells were present either through cell transfer or survival after nonmyeloablative irradiation. In vivo depletion of CD4 or CD8 T cells completely eliminated antitumor efficacy of the lymphodepletion/anti-PD-L1 therapy, indicating that both T cell subsets are necessary for tumor rejection. Elimination of myeloma by T cells occurs relatively quickly as tumor cells in the bone marrow were nearly nondetectable by 5 d after the first anti-PD-L1 treatment, suggesting that antimyeloma reactivity is primarily mediated by preactivated T cells, rather than newly generated myeloma-reactive T cells. Anti-PD-L1 plus lymphodepletion failed to improve survival in two solid tumor models, but demonstrated significant efficacy in two hematologic malignancy models. In summary, our results support the clinical testing of lymphodepletion and PD-1/PD-L1 blockade as a novel approach for improving the survival of patients with multiple myeloma.
van der Merwe, M., et al. (2013). "Recipient myeloid-derived immunomodulatory cells induce PD-1 ligand-dependent donor CD4+Foxp3+ regulatory T cell proliferation and donor-recipient immune tolerance after murine nonmyeloablative bone marrow transplantation" J Immunol 191(11): 5764-5776. PubMed
We showed previously that nonmyeloablative total lymphoid irradiation/rabbit anti-thymocyte serum (TLI/ATS) conditioning facilitates potent donor-recipient immune tolerance following bone marrow transplantation (BMT) across MHC barriers via recipient invariant NKT (iNKT) cell-derived IL-4-dependent expansion of donor Foxp3(+) naturally occurring regulatory T cells (nTregs). In this study, we report a more specific mechanism. Wild-type (WT) BALB/c (H-2(d)) hosts were administered TLI/ATS and BMT from WT or STAT6(-/-) C57BL/6 (H-2(b)) donors. Following STAT6(-/-) BMT, donor nTregs demonstrated no loss of proliferation in vivo, indicating that an IL-4-responsive population in the recipient, rather than the donor, drives donor nTreg proliferation. In graft-versus-host disease (GVHD) target organs, three recipient CD11b(+) cell subsets (Gr-1(high)CD11c(-), Gr-1(int)CD11c(-), and Gr-1(low)CD11c(+)) were enriched early after TLI/ATS + BMT versus total body irradiation/ATS + BMT. Gr-1(low)CD11c(+) cells induced potent H-2K(b+)CD4(+)Foxp3(+) nTreg proliferation in vitro in 72-h MLRs. Gr-1(low)CD11c(+) cells were reduced significantly in STAT6(-/-) and iNKT cell-deficient Jalpha18(-/-) BALB/c recipients after TLI/ATS + BMT. Depletion of CD11b(+) cells resulted in severe acute GVHD, and adoptive transfer of WT Gr-1(low)CD11c(+) cells to Jalpha18(-/-) BALB/c recipients of TLI/ATS + BMT restored day-6 donor Foxp3(+) nTreg proliferation and protection from CD8 effector T cell-mediated GVHD. Blockade of programmed death ligand 1 and 2, but not CD40, TGF-beta signaling, arginase 1, or iNOS, inhibited nTreg proliferation in cocultures of recipient-derived Gr-1(low)CD11c(+) cells with donor nTregs. Through iNKT-dependent Th2 polarization, myeloid-derived immunomodulatory dendritic cells are expanded after nonmyeloablative TLI/ATS conditioning and allogeneic BMT, induce PD-1 ligand-dependent donor nTreg proliferation, and maintain potent graft-versus-host immune tolerance.
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.
Willimsky, G., et al. (2013). "Virus-induced hepatocellular carcinomas cause antigen-specific local tolerance" J Clin Invest 123(3): 1032-1043. PubMed
T cell surveillance is often effective against virus-associated tumors because of their high immunogenicity. It is not clear why surveillance occasionally fails, particularly against hepatitis B virus- or hepatitis C virus-associated hepatocellular carcinoma (HCC). We established a transgenic murine model of virus-induced HCC by hepatocyte-specific adenovirus-induced activation of the oncogenic SV40 large T antigen (TAg). Adenovirus infection induced cytotoxic T lymphocytes (CTLs) targeted against the virus and TAg, leading to clearance of the infected cells. Despite the presence of functional, antigen-specific T cells, a few virus-infected cells escaped immune clearance and progressed to HCC. These cells expressed TAg at levels similar to HCC isolated from neonatal TAg-tolerant mice, suggesting that CTL clearance does not select for cells with low immunogenicity. Virus-infected mice revealed significantly greater T cell infiltration in early-stage HCC compared with that in late-stage HCC, demonstrating progressive local immune suppression through inefficient T cell infiltration. Programmed cell death protein-1 (PD-1) and its ligand PD-L1 were expressed in all TAg-specific CD8+ T cells and HCC, respectively, which contributed to local tumor-antigen-specific tolerance. Thus, we have developed a model of virus-induced HCC that may allow for a better understanding of human HCC.
Coers, J., et al. (2011). "Compensatory T cell responses in IRG-deficient mice prevent sustained Chlamydia trachomatis infections" PLoS Pathog 7(6): e1001346. PubMed
The obligate intracellular pathogen Chlamydia trachomatis is the most common cause of bacterial sexually transmitted diseases in the United States. In women C. trachomatis can establish persistent genital infections that lead to pelvic inflammatory disease and sterility. In contrast to natural infections in humans, experimentally induced infections with C. trachomatis in mice are rapidly cleared. The cytokine interferon-gamma (IFNgamma) plays a critical role in the clearance of C. trachomatis infections in mice. Because IFNgamma induces an antimicrobial defense system in mice but not in humans that is composed of a large family of Immunity Related GTPases (IRGs), we questioned whether mice deficient in IRG immunity would develop persistent infections with C. trachomatis as observed in human patients. We found that IRG-deficient Irgm1/m3((-/-)) mice transiently develop high bacterial burden post intrauterine infection, but subsequently clear the infection more efficiently than wildtype mice. We show that the delayed but highly effective clearance of intrauterine C. trachomatis infections in Irgm1/m3((-/-)) mice is dependent on an exacerbated CD4(+) T cell response. These findings indicate that the absence of the predominant murine innate effector mechanism restricting C. trachomatis growth inside epithelial cells results in a compensatory adaptive immune response, which is at least in part driven by CD4(+) T cells and prevents the establishment of a persistent infection in mice.
- Immunology and Microbiology,
Diverse cell types establish a pathogenic immune environment in peripheral neuropathy.
In Journal of Neuroinflammation on 23 May 2025 by Choi, J., Strickland, A., et al.
Neuroinflammation plays a complex and context-dependent role in many neurodegenerative diseases. We identified a key pathogenic function of macrophages in a mouse model of a rare human congenital neuropathy in which SARM1, the central executioner of axon degeneration, is activated by hypomorphic mutations in the axon survival factor NMNAT2. Macrophage depletion blocked and reversed neuropathic phenotypes in this sarmopathy model, revealing SARM1-dependent neuroimmune mechanisms as key drivers of disease pathogenesis. In this study, we investigated the impact of chronic subacute SARM1 activation on the peripheral nerve milieu using single cell/nucleus RNA-sequencing (sc/snRNA-seq). Our analyses reveal an expansion of immune cells (macrophages and T lymphocytes) and repair Schwann cells, as well as significant transcriptional alterations to a wide range of nerve-resident cell types. Notably, endoneurial fibroblasts show increased expression of chemokines (Ccl9, Cxcl5) and complement components (C3, C4b, C6) in response to chronic SARM1 activation, indicating enhanced immune cell recruitment and immune response regulation by non-immune nerve-resident cells. Analysis of CD45+ immune cells in sciatic nerves revealed an expansion of an Il1b+ macrophage subpopulation with increased expression of markers associated with phagocytosis and T cell activation/proliferation. We also found a significant increase in T cells in sarmopathic nerves. Remarkably, T cell depletion rescued motor phenotypes in the sarmopathy model. These findings delineate the significant changes chronic SARM1 activation induces in peripheral nerves and highlights the potential of immunomodulatory therapies for SARM1-dependent peripheral neurodegenerative disease. Ā© 2025. The Author(s).
- In Vivo,
- Mus musculus (House mouse),
- Cardiovascular biology,
- Immunology and Microbiology
Anti-TGF-Ī²/PD-L1 bispecific antibody synergizes with radiotherapy to enhance antitumor immunity and mitigate radiation-induced pulmonary fibrosis.
In Journal of Hematology & Oncology on 5 March 2025 by Wu, Y., Yan, Y., et al.
Despite the success of immune checkpoint inhibitors (ICIs) in multiple malignant tumors, a significant proportion of patients remain unresponsive to treatment. Radiotherapy (RT) elicits immunogenic antitumor responses but concurrently activates several immune evasion mechanisms. Our earlier research demonstrated the efficacy of YM101, an anti-TGF-Ī²/PD-L1 bispecific antibody, in stroma-rich tumors. Nevertheless, YM101 has demonstrated reduced effectiveness in non-inflamed tumors characterized by poor immune cell infiltration. This study investigated the potential synergy between RT and YM101 in overcoming immunotherapy resistance and mitigating RT-induced pulmonary fibrosis. The antitumor activity and survival outcomes of RT plus YM101 treatment in vivo were explored in several non-inflamed murine tumor models. Furthermore, the inhibition of pulmonary metastases was assessed in a pulmonary metastasis model. The impact of RT on dendritic cell (DC) maturation was quantified by flow cytometry, whereas cytokine and chemokine secretions were measured by ELISA. To comprehensively characterize changes in the tumor microenvironment, we utilized a combination of methods, including flow cytometry, IHC staining, multiplex inmunofluorecence and RNA sequencing. Additionally, we evaluated the impact of YM101 on RT-induced pulmonary fibrosis. RT plus YM101 significantly inhibited tumor growth, prolonged survival and inhibited pulmonary metastases compared with monotherapies in non-inflamed tumors with poor immune infiltration. RT promoted DC maturation in a dose-dependent manner and increased the secretions of multiple proinflammatory cytokines. Mechanistically, RT plus YM101 simultaneously increased the infiltration and activation of intratumoral DCs and tumor-infiltrating lymphocytes and reshaped the tumor microenvironment landscape. Notably, YM101 attenuated both RT-induced peritumoral fibrosis and pulmonary fibrosis. Our findings suggest that RT combined with YM101 enhances antitumor immunity and overcomes resistance in non-inflamed tumors in preclinical models, while simultaneously showing potential in mitigating RT-induced fibrosis. This combination therapy demonstrates promise in overcoming ICI resistance, while potentially sparing normal pulmonary tissue, thereby providing a strong rationale for further clinical investigations. Ā© 2025. The Author(s).
- Cancer Research,
- Endocrinology and Physiology,
- Immunology and Microbiology
Caerin 1.1/1.9-mediated antitumor immunity depends on IFNAR-Stat1 signalling of tumour infiltrating macrophage by autocrine IFNĪ± and is enhanced by CD47 blockade.
In Scientific Reports on 30 January 2025 by Li, J., Luo, Y., et al.
Previously, we demonstrated that natural host-defence peptide caerin 1.1/caerin 1.9 (F1/F3) increases the efficacy of anti-PD-1 and therapeutic vaccine, in a HPV16ā+āTC-1 tumour model, but the anti-tumor mechanism of F1/F3 is still unclear. In this study, we explored the impact of F1/F3 on the tumor microenvironment in a transplanted B16 melanoma model, and further investigated the mechanism of action of F1/F3 using monoclonal antibodies to deplete relevant cells, gene knockout mice and flow cytometry. We show that F1/F3 is able to inhibit the growth of melanoma B16 tumour cells both in vitro and in vivo. Depletion of macrophages, blockade of IFNĪ± receptor, and Stat1 inhibition each abolishes F1/F3-mediated antitumor responses. Subsequent analysis reveals that F1/F3 increases the tumour infiltration of inflammatory macrophages, upregulates the level of IFNĪ± receptor, and promotes the secretion of IFNĪ± by macrophages. Interestingly, F1/F3 upregulates CD47 level on tumour cells; and blocking CD47 increases F1/F3-mediated antitumor responses. Furthermore, F1/F3 intratumor injection, CD47 blockade, and therapeutic vaccination significantly increases the survival time of B16 tumour-bearing mice. These results indicate that F1/F3 may be effective to improve the efficacy of ICB and therapeutic vaccine-based immunotherapy for human epithelial cancers and warrants consideration for clinical trials. Ā© 2025. The Author(s).
Brucella abortus impairs T lymphocyte responsiveness by mobilizing IL-1RA-secreting omental neutrophils.
In Nature Communications on 20 January 2025 by Pellegrini, J. M., GonzƔlez-Espinoza, G., et al.
Immune evasion strategies of Brucella, the etiologic agent of brucellosis, a global zoonosis, remain partially understood. The omentum, a tertiary lymphoid organ part of visceral adipose tissue, has never been explored as a Brucella reservoir. We report that B. abortus infects and replicates within murine omental macrophages. Throughout the chronic phase of infection, the omentum accumulates macrophages, monocytes and neutrophils. The maintenance of PD-L1+Sca-1+ macrophages, monocytes and neutrophils in the omentum depends on the wadC-encoded determinant of Brucella LPS. We demonstrate that PD-L1+Sca-1+ murine omental neutrophils produce high levels of IL-1RA leading to T cell hyporesponsiveness. These findings corroborate brucellosis patient analysis of whole blood displaying upregulation of PDL1 and Ly6E genes, and of serum exhibiting high levels of IL-1RA. Overall, the omentum, a reservoir for B. abortus, promotes bacterial persistence and causes CD4+ and CD8+ T cell immunosuppression by IL-1RA secreted by PD-L1+Sca-1+ neutrophils. Ā© 2025. The Author(s).
- Cancer Research,
- Immunology and Microbiology
MerTK+ macrophages promote melanoma progression and immunotherapy resistance through AhR-ALKAL1 activation.
In Science Advances on 4 October 2024 by Wu, N., Li, J., et al.
Despite our increasing understanding of macrophage heterogeneity, drivers of macrophage phenotypic and functional polarization in the microenvironment are not fully elucidated. Here, our single-cell RNA sequencing data identify a subpopulation of macrophages expressing high levels of the phagocytic receptor MER proto-oncogene tyrosine kinase (MerTK+ macrophages), which is closely associated with melanoma progression and immunotherapy resistance. Adoptive transfer of the MerTK+ macrophages into recipient mice notably accelerated tumor growth regardless of macrophage depletion. Mechanistic studies further revealed that ALK And LTK Ligand 1 (ALKAL1), a target gene of aryl hydrocarbon receptor (AhR), facilitated MerTK phosphorylation, resulting in heightened phagocytic activity of MerTK+ macrophages and their subsequent polarization toward an immunosuppressive phenotype. Specifically targeted delivery of AhR antagonist to tumor-associated macrophages with mannosylated micelles could suppress MerTK expression and improved the therapeutic efficacy of anti-programmed cell death ligand 1 therapy. Our findings shed light on the regulatory mechanism of MerTK+ macrophages and provide strategies for improving the efficacy of melanoma immunotherapy.
- Cancer Research,
- Immunology and Microbiology
The type 2 cytokine Fc-IL-4 revitalizes exhausted CD8+ T cells against cancer.
In Nature on 1 October 2024 by Feng, B., Bai, Z., et al.
Current cancer immunotherapy predominately focuses on eliciting type 1 immune responses fighting cancer; however, long-term complete remission remains uncommon1,2. A pivotal question arises as toĀ whether type 2 immunity can be orchestrated alongside type 1-centric immunotherapy to achieve enduring response against cancer3,4. Here we show that an interleukin-4 fusion protein (Fc-IL-4), a typical type 2 cytokine, directly acts on CD8+ T cells and enriches functional terminally exhausted CD8+ T (CD8+ TTE) cells in the tumour. Consequently, Fc-IL-4 enhances antitumour efficacy of type 1 immunity-centric adoptive T cell transfer or immune checkpoint blockade therapies and induces durable remission across several syngeneic and xenograft tumour models. Mechanistically, we discovered that Fc-IL-4 signals through both signal transducer and activator of transcription 6 (STAT6) and mammalian target of rapamycin (mTOR)Ā pathways, augmenting the glycolytic metabolism and the nicotinamide adenine dinucleotide (NAD) concentration of CD8+ TTE cells in a lactate dehydrogenase A-dependent manner. The metabolic modulation mediated by Fc-IL-4 is indispensable for reinvigorating intratumoural CD8+ TTE cells. These findings underscore Fc-IL-4 as a potent type 2 cytokine-based immunotherapy that synergizes effectively with type 1 immunity to elicit long-lasting responses against cancer. Our study not only sheds light on the synergy between these two types of immune responses, but also unveils an innovative strategy for advancing next-generation cancer immunotherapy by integrating type 2 immune factors. Ā© 2024. The Author(s).
- Cancer Research,
- Immunology and Microbiology,
- Stem Cells and Developmental Biology
Novel Arf1 Inhibitors Drive Cancer Stem Cell Aging and Potentiate Anti-Tumor Immunity.
In Advanced Science (Weinheim, Baden-Wurttemberg, Germany) on 1 October 2024 by Wang, Y., Li, Q., et al.
The small G protein Arf1 has been identified as playing a selective role in supporting cancer stem cells (CSCs), making it an attractive target for cancer therapy. However, the current Arf1 inhibitors have limited translational potential due to their high toxicity and low specificity. In this study, two new potent small-molecule inhibitors of Arf1, identified as DU101 and DU102, for cancer therapy are introduced. Preclinical tumor models demonstrate that these inhibitors triggered a cascade of aging in CSCs and enhance anti-tumor immunity in mouse cancer and PDX models. Through single-cell sequencing, the remodeling of the tumor immune microenvironment induced by these new Arf1 inhibitors is analyzed and an increase in tumor-associated CD8+ CD4+ double-positive T (DPT) cells is identified. These DPT cells exhibit superior features of active CD8 single-positive T cells and a higher percentage of TCF1+PD-1+, characteristic of stem-like T cells. The frequency of tumor-infiltrating stem-like DPT cells correlates with better disease-free survival (DFS) in cancer patients, indicating that these inhibitors may offer a novel cancer immunotherapy strategy by converting the cold tumor immune microenvironment into a hot one, thus expanding the potential for immunotherapy in cancer patients. Ā© 2024 The Author(s). Advanced Science published by WileyāVCH GmbH.
- Immunology and Microbiology
Id2 levels determine the development of effector vs. exhausted tissue-resident memory CD8+T cells during CNS chronic infection
Preprint on BioRxiv : the Preprint Server for Biology on 30 July 2024 by Coulibaly, A. S. K., Nozeran, L., et al.
ABSTRACT Tissue-resident memory T cells (Trm) are essential for regional immunity in non-lymphoid tissues. Although single-cell transcriptomics have revealed Trm heterogeneity in various diseases, the molecular mechanisms behind this diversity are unclear. To investigate this, we used Toxoplasma gondii ( T. gondii ) infection, which persists in the central nervous system (CNS) and is controlled by brain CD8 + Trm. Our single-cell transcriptomic analysis of brain CD8 + T cells from T. gondii -infected mice showed heterogeneous expression of the transcriptional regulator Id2, correlating with different functional states. Using mixed bone marrow chimeras, we found that Id2-deficiency in T cells caused parasite-specific Trm to develop an altered phenotype with diminished effector functions and reduced expression of CD49a. Furthermore, loss of Id2 in brain-infiltrating CD8 + T cells led to the accumulation of exhausted PD1 + Tox + CD8 + Trm cells, while Id2 overexpression repressed T cell exhaustion. Overall, our study shows that Id2 levels dictate the acquisition of effector vs. exhausted phenotypes in CD8 + Trm during chronic CNS infection. One sentence Summary Id2 expression level regulates the functional heterogeneity of brain Trm during CNS chronic infection
- Biochemistry and Molecular biology,
- Cancer Research,
- Cell Biology,
- Immunology and Microbiology
Metabolic Reprogramming of Tumor-Associated Macrophages Using Glutamine Antagonist JHU083 Drives Tumor Immunity in Myeloid-Rich Prostate and Bladder Cancers.
In Cancer Immunology Research on 2 July 2024 by Praharaj, M., Shen, F., et al.
Glutamine metabolism in tumor microenvironments critically regulates antitumor immunity. Using the glutamine-antagonist prodrug JHU083, we report potent tumor growth inhibition in urologic tumors by JHU083-reprogrammed tumor-associated macrophages (TAMs) and tumor-infiltrating monocytes. We show JHU083-mediated glutamine antagonism in tumor microenvironments induced by TNF, proinflammatory, and mTORC1 signaling in intratumoral TAM clusters. JHU083-reprogrammed TAMs also exhibited increased tumor cell phagocytosis and diminished proangiogenic capacities. In vivo inhibition of TAM glutamine consumption resulted in increased glycolysis, a broken tricarboxylic acid (TCA) cycle, and purine metabolism disruption. Although the antitumor effect of glutamine antagonism on tumor-infiltrating T cells was moderate, JHU083 promoted a stem cell-like phenotype in CD8+ T cells and decreased the abundance of regulatory T cells. Finally, JHU083 caused a global shutdown in glutamine-utilizing metabolic pathways in tumor cells, leading to reduced HIF-1Ī±, c-MYC phosphorylation, and induction of tumor cell apoptosis, all key antitumor features. Altogether, our findings demonstrate that targeting glutamine with JHU083 led to suppressed tumor growth as well as reprogramming of immunosuppressive TAMs within prostate and bladder tumors that promoted antitumor immune responses. JHU083 can offer an effective therapeutic benefit for tumor types that are enriched in immunosuppressive TAMs. Ā©2024 The Authors; Published by the American Association for Cancer Research.
- In Vivo,
- Mus musculus (House mouse),
- Biochemistry and Molecular biology,
- Cell Biology,
- Immunology and Microbiology
A CD36-dependent non-canonical lipid metabolism program promotes immune escape and resistance to hypomethylating agent therapy in AML.
In Cell Reports Medicine on 18 June 2024 by Guo, H. Z., Feng, R. X., et al.
Environmental lipids are essential for fueling tumor energetics, but whether these exogenous lipids transported into cancer cells facilitate immune escape remains unclear. Here, we find that CD36, a transporter for exogenous lipids, promotes acute myeloid leukemia (AML) immune evasion. We show that, separately from its established role in lipid oxidation, CD36 on AML cells senses oxidized low-density lipoprotein (OxLDL) to prime the TLR4-LYN-MYD88-nuclear factor ĪŗB (NF-ĪŗB) pathway, and exogenous palmitate transfer via CD36 further potentiates this innate immune pathway by supporting ZDHHC6-mediated MYD88 palmitoylation. Subsequently, NF-ĪŗB drives the expression of immunosuppressive genes that inhibit anti-tumor TĀ cell responses. Notably, high-fat-diet or hypomethylating agent decitabine treatment boosts the immunosuppressive potential of AML cells by hijacking CD36-dependent innate immune signaling, leading to a dampened therapeutic effect. This work is of translational interest because lipid restriction by US Food and Drug Administration (FDA)-approved lipid-lowering statin drugs improves the efficacy of decitabine therapy by weakening leukemic CD36-mediated immunosuppression. Copyright Ā© 2024 The Authors. Published by Elsevier Inc. All rights reserved.
- Biochemistry and Molecular biology,
- Immunology and Microbiology
Immunogenicity and efficacy of CNA25 as a potential whole-cell vaccine against systemic candidiasis.
In EMBO Molecular Medicine on 1 June 2024 by Sahu, S. R., Dutta, A., et al.
Disseminated fungal infections account for ~1.5 million deaths per year worldwide, and mortality may increase further due to a rise in the number of immunocompromised individuals and drug-resistance fungal species. Since an approved antifungal vaccine is yet to be available, this study explored the immunogenicity and vaccine efficacy of a DNA polymerase mutant strain of Candida albicans. CNA25 is a pol32ĪĪ strain that exhibits growth defects and does not cause systemic candidiasis in mice. Immunized mice with live CNA25 were fully protected against C. albicans and C. parapsilosis but partially against C. tropicalis and C. glabrata infections. CNA25 induced steady expression of TLR2 and Dectin-1 receptors leading to a faster recognition and clearance by the immune system associated with the activation of protective immune responses mostly mediated by neutrophils, macrophages, NK cells, B cells, and CD4+ and CD8+ T cells. Molecular blockade of Dectin-1, IL-17, IFNĪ³, and TNFĪ± abolished resistance to reinfection. Altogether, this study suggested that CNA25 collectively activates innate, adaptive, and trained immunity to be a promising live whole-cell vaccine against systemic candidiasis. Ā© 2024. The Author(s).
- Immunology and Microbiology,
- COVID-19
A T cell-based SARS-CoV-2 spike protein vaccine provides protection without antibodies.
In JCI Insight on 8 March 2024 by Shi, J., Zheng, J., et al.
PubMed
SARS-CoV-2 spike-based vaccines are used to control the COVID-19 pandemic. However, emerging variants have become resistant to antibody neutralization and further mutations may lead to full resistance. We tested whether T cells alone could provide protection without antibodies. We designed a T cell-based vaccine in which SARS-CoV-2 spike sequences were rearranged and attached to ubiquitin. Immunization of mice with the vaccine induced no specific antibodies, but strong specific T cell responses. We challenged mice with SARS-CoV-2 wild-type strain or an Omicron variant after the immunization and monitored survival or viral titers in the lungs. The mice were significantly protected against death and weight loss caused by the SARS-CoV-2 wild-type strain, and the viral titers in the lungs of mice challenged with the SARS-CoV-2 wild-type strain or the Omicron variant were significantly reduced. Importantly, depletion of CD4+ or CD8+ T cells led to significant loss of the protection. Our analyses of spike protein sequences of the variants indicated that fewer than one-third presented by dominant HLA alleles were mutated and that most of the mutated epitopes were in the subunit 1 region. As the subunit 2 region is conservative, the vaccines targeting spike protein are expected to protect against future variants due to the T cell responses.
The efficacy of chemotherapy is limited by intratumoral senescent cells expressing PD-L2.
In Nature Cancer on 1 March 2024 by Chaib, S., Lopez-Dominguez, J. A., et al.
Chemotherapy often generates intratumoral senescent cancer cells that strongly modify the tumor microenvironment, favoring immunosuppression and tumor growth. We discovered, through an unbiased proteomics screen, that the immune checkpoint inhibitor programmed cell death 1 ligand 2 (PD-L2) is highly upregulated upon induction of senescence in different types of cancer cells. PD-L2 is not required for cells to undergo senescence, but it is critical for senescent cells to evade the immune system and persist intratumorally. Indeed, after chemotherapy, PD-L2-deficient senescent cancer cells are rapidly eliminated and tumors do not produce the senescence-associated chemokines CXCL1 and CXCL2. Accordingly, PD-L2-deficient pancreatic tumors fail to recruit myeloid-derived suppressor cells and undergo regression driven by CD8 T cells after chemotherapy. Finally, antibody-mediated blockade of PD-L2 strongly synergizes with chemotherapy causing remission of mammary tumors in mice. The combination of chemotherapy with anti-PD-L2 provides a therapeutic strategy that exploits vulnerabilities arising from therapy-induced senescence. Ā© 2024. The Author(s).
- Immunology and Microbiology
LRP11 promotes stem-like T cells via MAPK13-mediated TCF1 phosphorylation, enhancing anti-PD1 immunotherapy.
In Journal for Immunotherapy of Cancer on 25 January 2024 by Sun, L., Ma, Z., et al.
PubMed
Tumor-infiltrating T cells enter an exhausted or dysfunctional state, which limits antitumor immunity. Among exhausted T cells, a subset of cells with features of progenitor or stem-like cells has been identified as TCF1+ CD8+ T cells that respond to immunotherapy. In contrast to the finding that TCF1 controls epigenetic and transcriptional reprogramming in tumor-infiltrating stem-like T cells, little is known about the regulation of TCF1. Emerging data show that elevated body mass index is associated with outcomes of immunotherapy. However, the mechanism has not been clarified. We investigated the proliferation of splenic lymphocytes or CD8+ T cells induced by CD3/CD28 stimulation in vitro. We evaluated the effects of low-density lipoprotein (LDL) and LRP11 inhibitors, as well as MAPK13 inhibitors. Additionally, we used shRNA technology to validate the roles of LRP11 and MAPK13. In an in vivo setting, we employed male C57BL/6J injected with B16 cells or MC38 cells to build a tumor model to assess the effects of LDL and LRP11 inhibitors, LRP11 activators, MAPK13 inhibitors on tumor growth. Flow cytometry was used to measure cell proportions and activation status. Molecular interactions and TCF1 status were examined using Western blotting. Moreover, we employed RNA sequencing to investigate the effects of LDL stimulation and MAPK13 inhibition in CD8+ T cells. By using a tumor-bearing mouse model, we found that LDL-induced tumor-infiltrating TCF1+PD1+CD8+ T cells. Using a cell-based chimeric receptor screening system, we showed that LRP11 interacted with LDL and activated TCF1. LRP11 activation enhanced TCF1+PD1+CD8+ T-cell-mediated antitumor immunity, consistent with LRP11 blocking impaired T-cell function. Mechanistically, LRP11 activation induces MAPK13 activation. Then, MAPK13 phosphorylates TCF1, leading to increase of stem-like T cells. LRP11-MAPK13-TCF1 enhanced antitumor immunity and induced tumor-infiltrating stem-like T cells. Ā© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Immunology and Microbiology
Anti-PD-L1 therapy altered inflammation but not survival in a lethal murine hepatitis virus-1 pneumonia model.
In Frontiers in Immunology on 23 January 2024 by Curran, C. S., Cui, X., et al.
PubMed
Because prior immune checkpoint inhibitor (ICI) therapy in cancer patients presenting with COVID-19 may affect outcomes, we investigated the beta-coronavirus, murine hepatitis virus (MHV)-1, in a lethal pneumonia model in the absence (Study 1) or presence of prior programmed cell death ligand-1 (PD-L1) antibody (PD-L1mAb) treatment (Study 2). In Study 1, animals were inoculated intratracheally with MHV-1 or vehicle and evaluated at day 2, 5, and 10 after infection. In Study 2, uninfected or MHV-1-infected animals were pretreated intraperitoneally with control or PD-L1-blocking antibodies (PD-L1mAb) and evaluated at day 2 and 5 after infection. Each study examined survival, physiologic and histologic parameters, viral titers, lung immunophenotypes, and mediator production. Study 1 results recapitulated the pathogenesis of COVID-19 and revealed increased cell surface expression of checkpoint molecules (PD-L1, PD-1), higher expression of the immune activation marker angiotensin converting enzyme (ACE), but reduced detection of the MHV-1 receptor CD66a on immune cells in the lung, liver, and spleen. In addition to reduced detection of PD-L1 on all immune cells assayed, PD-L1 blockade was associated with increased cell surface expression of PD-1 and ACE, decreased cell surface detection of CD66a, and improved oxygen saturation despite reduced blood glucose levels and increased signs of tissue hypoxia. In the lung, PD-L1mAb promoted S100A9 but inhibited ACE2 production concomitantly with pAKT activation and reduced FOXO1 levels. PD-L1mAb promoted interferon-Ī³ but inhibited IL-5 and granulocyte-macrophageĀ colony-stimulating factor (GM-CSF) production, contributing to reduced bronchoalveolar lavage levels of eosinophils and neutrophils. In the liver, PD-L1mAb increased viral clearance in association with increased macrophage and lymphocyte recruitment and liver injury. PD-L1mAb increased the production of virally induced mediators of injury, angiogenesis, and neuronal activity that may play role in COVID-19 and ICI-related neurotoxicity. PD-L1mAb did not affect survival in this murine model. In Study 1 and Study 2, ACE was upregulated and CD66a and ACE2 were downregulated by either MHV-1 or PD-L1mAb. CD66a is not only the MHV-1 receptor but also an identified immune checkpoint and a negative regulator of ACE. Crosstalk between CD66a and PD-L1 or ACE/ACE2 may provide insight into ICI therapies. These networks may also play role in the increased production of S100A9 and neurological mediators in response to MHV-1 and/or PD-L1mAb, which warrant further study. Overall, these findings support observational data suggesting that prior ICI treatment does not alter survival in patients presenting with COVID-19. Copyright Ā© 2024 Curran, Cui, Li, Jeakle, Sun, Demirkale, Minkove, Hoffmann, Dhamapurkar, Chumbris, Bolyard, Iheanacho, Eichacker and Torabi-Parizi.
- Mus musculus (House mouse)
Antitumor Effect of Platinum-Modified STING Agonist MSA-2.
In ACS Omega on 16 January 2024 by Wang, M., Cai, Y., et al.
PubMed
The stimulator of interferon genes (STING)-activated innate immune pathway is strong and durable for tumor immunotherapy. MSA-2 is an available non-nucleotide human STING agonist that promotes the tumor immunotherapy of STING activation. However, strategies for remolding and improving the immunotherapy effects of MSA-2 are of value for clinical applications. Here, we synthesized the platinum salt-modified MSA-2 (MSA-2-Pt) due to platinum salt being a classic chemotherapeutic drug. We found that MSA-2-Pt could achieve double-effect antitumor immunotherapy, including inducing cell death by platinum and activating the STING pathway by MSA-2. In the colon carcinoma MC38 model (sensitive to immune checkpoint immunotherapy tumor) and melanoma B16F10 model (poorly immunogenic and highly aggressive tumor), the MSA-2-Pt had a good antitumor effect, which was a little better than MSA-2 with intratumor injections. The results present a promising strategy for STING activation in tumor immunotherapy and broadening platinum-based drugs. Ā© 2024 The Authors. Published by American Chemical Society.
- Mus musculus (House mouse),
- Immunology and Microbiology
Electrostatic-driven Interactions Enhance Intratumoral Retention and Antitumor Efficacy of Immune Checkpoint Blockade Antibodies
Preprint on BioRxiv : the Preprint Server for Biology on 23 December 2023 by Mohanty, R. P., Pan, Y., et al.
ABSTRACT Tumor extracellular matrix (ECM) forms a net negative charged network that interacts with and hinders the transport of molecules partly based on electrostatic interactions. The focus on drug delivery in solid tumors has traditionally been on developing neutral charge coatings to minimize interactions with the ECM for improved transport. In contrast to this prior work, we recently found a cationic peptide that interacted electrostatically with the negatively charged components of the ECM, resulting in enhanced uptake and retention of nanoparticles in tumor ECM and tumor tissue. Based on this previous study, here, we hypothesize that the electrostatically driven interactions of the cationic peptide will improve the binding and retention of immune checkpoint blockade antibodies (ICBs), ultimately enhancing their antitumor immunogenic responses. We prepared peptide antibody (Ab) conjugates by conjugating the cationic peptide to ICBs, anti-cytotoxic T lymphocyte antigen 4 (ā-CTLA4) and anti-programmed cell death ligand-1 (ā-PD-L1) Abs, using copper-free click chemistry. We confirmed an average of 1 ā 2 peptides per Ab. The cationic peptide electrostatically interacted with the net negatively charged tumor ECM and improved the binding of the Abs to the tumor ECM without affecting their antigen recognition capacities. Modifying the Abs due to cationic peptide conjugation reduced the systemic exposure of the Abs and did not induce treatment-related toxicities. We quantified a significantly higher population of tumor-infiltrating CD8 + T cells and a significant depletion of regulatory T cells in the tumor and tumor-draining lymph nodes upon peptide conjugation, which resulted in a better therapeutic outcome of the ICBs. ONE SENTENCE SUMMARY Electrostatic interaction-based intratumoral retention enhances antitumor responses of immune checkpoint blockade antibodies upon local administration.
- Cancer Research,
- Cell Biology,
- Immunology and Microbiology
Fasting-Mimicking Diet Inhibits Autophagy and Synergizes with Chemotherapy to Promote T-Cell-Dependent Leukemia-Free Survival.
In Cancers on 16 December 2023 by Buono, R., Tucci, J., et al.
PubMed
Fasting mimicking diets (FMDs) are effective in the treatment of many solid tumors in mouse models, but their effect on hematologic malignancies is poorly understood, particularly in combination with standard therapies. Here we show that cycles of a 3-day FMD given to high-fat-diet-fed mice once a week increased the efficacy of vincristine to improve survival from BCR-ABL B acute lymphoblastic leukemia (ALL). In mice fed a standard diet, FMD cycles in combination with vincristine promoted cancer-free survival. RNA seq and protein assays revealed a vincristine-dependent decrease in the expression of multiple autophagy markers, which was exacerbated by the fasting/FMD conditions. The autophagy inhibitor chloroquine could substitute for fasting/FMD to promote cancer-free survival in combination with vincristine. In vitro, targeted inhibition of autophagy genes ULK1 and ATG9a strongly potentiated vincristine's toxicity. Moreover, anti-CD8 antibodies reversed the effects of vincristine plus fasting/FMD in promoting leukemia-free survival in mice, indicating a central role of the immune system in this response. Thus, the inhibition of autophagy and enhancement of immune responses appear to be mediators of the fasting/FMD-dependent cancer-free survival in ALL mice.
- Cancer Research,
- Immunology and Microbiology,
- Stem Cells and Developmental Biology
A SOX9-B7x axis safeguards dedifferentiated tumor cells from immune surveillance to drive breast cancer progression.
In Developmental Cell on 4 December 2023 by Liu, Y., John, P., et al.
How dedifferentiated stem-like tumor cells evade immunosurveillance remains poorly understood. We show that the lineage-plasticity regulator SOX9, which is upregulated in dedifferentiated tumor cells, limits the number of infiltrating T lymphocytes in premalignant lesions of mouse basal-like breast cancer. SOX9-mediated immunosuppression is required for the progression of in situ tumors to invasive carcinoma. SOX9 induces the expression of immune checkpoint B7x/B7-H4 through STAT3 activation and direct transcriptional regulation. B7x is upregulated in dedifferentiated tumor cells and protects them from immunosurveillance. B7x also protects mammary gland regeneration in immunocompetent mice. In advanced tumors, B7x targeting inhibits tumor growth and overcomes resistance to anti-PD-L1 immunotherapy. In human breast cancer, SOX9 and B7x expression are correlated and associated with reduced CD8+ TĀ cell infiltration. This study, using mouse models, cell lines, and patient samples, identifies a dedifferentiation-associated immunosuppression mechanism and demonstrates the therapeutic potential of targeting the SOX9-B7x pathway in basal-like breast cancer. Copyright Ā© 2023 Elsevier Inc. All rights reserved.
- Immunology and Microbiology
Interventional hydrogel microsphere vaccine as an immune amplifier for activated antitumour immunity after ablation therapy.
In Nature Communications on 11 July 2023 by Liu, X., Zhuang, Y., et al.
PubMed
The response rate of pancreatic cancer to chemotherapy or immunotherapy pancreatic cancer is low. Although minimally invasive irreversible electroporation (IRE) ablation is a promising option for irresectable pancreatic cancers, the immunosuppressive tumour microenvironment that characterizes this tumour type enables tumour recurrence. Thus, strengthening endogenous adaptive antitumour immunity is critical for improving the outcome of ablation therapy and post-ablation immune therapy. Here we present a hydrogel microsphere vaccine that amplifies post-ablation anti-cancer immune response via releasing its cargo of FLT3L and CD40L at the relatively lower pH of the tumour bed. The vaccine facilitates migration of the tumour-resident type 1 conventional dendritic cells (cDC1) to the tumour-draining lymph nodes (TdLN), thus initiating the cDC1-mediated antigen cross-presentation cascade, resulting in enhanced endogenous CD8+ T cell response. We show in an orthotopic pancreatic cancer model in male mice that the hydrogel microsphere vaccine transforms the immunologically cold tumour microenvironment into hot in a safe and efficient manner, thus significantly increasing survival and inhibiting the growth of distant metastases. Ā© 2023. The Author(s).
