InVivoMAb anti-mouse PD-1 (CD279)
Product Details
The J43 monoclonal antibody reacts with mouse PD-1 (programmed death-1) also known as CD279. PD-1 is a 50-55 kDa cell surface receptor encoded by the Pdcd1 gene that belongs to the CD28 family of the immunoglobulin superfamily. PD-1 is transiently expressed on CD4 and CD8 thymocytes as well as activated T and B lymphocytes and myeloid cells. PD-1 expression declines after successful elimination of antigen. Additionally, Pdcd1 mRNA is expressed in developing B lymphocytes during the pro-B-cell stage. PD-1ās structure includes a ITIM (immunoreceptor tyrosine-based inhibitory motif) suggesting that PD-1 negatively regulates TCR signals. PD-1 signals via binding its two ligands, PD-L1 and PD-L2 both members of the B7 family. Upon ligand binding, PD-1 signaling inhibits T-cell activation, leading to reduced proliferation, cytokine production, and T-cell death. Additionally, PD-1 is known to play key roles in peripheral tolerance and prevention of autoimmune disease in mice as PD-1 knockout animals show dilated cardiomyopathy, splenomegaly, and loss of peripheral tolerance. Induced PD-L1 expression is common in many tumors including squamous cell carcinoma, colon adenocarcinoma, and breast adenocarcinoma. PD-L1 overexpression results in increased resistance of tumor cells to CD8 T cell mediated lysis. In mouse models of melanoma, tumor growth can be transiently arrested via treatment with antibodies which block the interaction between PD-L1 and its receptor PD-1. For these reasons anti-PD-1 mediated immunotherapies are currently being explored as cancer treatments. The J43 antibody has been shown to block the binding of both mouse PD-L1-Ig and mouse PD-L2-Ig to PD-1.Specifications
| Isotype | Armenian hamster IgG |
|---|---|
| Recommended Isotype Control(s) | InVivoMAb polyclonal Armenian hamster IgG |
| Recommended Dilution Buffer | InVivoPure pH 6.5 Dilution Buffer |
| Conjugation | This product is unconjugated. Conjugation is available via our Antibody Conjugation Services. |
| Immunogen | Syrian Hamster BKH cells transfected with mouse PD-1 cDNA |
| Reported Applications |
in vivo blocking of PD-1/PD-L signaling in vitro PD-1 neutralization Western blot |
| Formulation |
PBS, pH 6.5 Contains no stabilizers or preservatives |
| Endotoxin |
<2EU/mg (<0.002EU/Ī¼g) Determined by LAL gel clotting assay |
| 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_1107747 |
| Molecular Weight | 150 kDa |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C. Do not freeze. |
Additional Formats
Recommended Products
-
Recommended Isotype Control(s)
InVivoMAb polyclonal Armenian hamster IgG
-
Recommended Dilution Buffer
InVivoPure pH 6.5 Dilution Buffer
in vivo blocking of PD-1/PD-L signaling
Li, J., et al. (2018). "Co-inhibitory Molecule B7 Superfamily Member 1 Expressed by Tumor-Infiltrating Myeloid Cells Induces Dysfunction of Anti-tumor CD8(+) T Cells" Immunity 48(4): 773-786 e775. PubMed
The molecular mechanisms whereby CD8(+) T cells become āexhaustedā in the tumor microenvironment remain unclear. Programmed death ligand-1 (PD-L1) is upregulated on tumor cells and PD-1-PD-L1 blockade has significant efficacy in human tumors; however, most patients do not respond, suggesting additional mechanisms underlying T cell exhaustion. B7 superfamily member 1 (B7S1), also called B7-H4, B7x, or VTCN1, negatively regulates T cell activation. Here we show increased B7S1 expression on myeloid cells from human hepatocellular carcinoma correlated with CD8(+) T cell dysfunction. B7S1 inhibition suppressed development of murine tumors. Putative B7S1 receptor was co-expressed with PD-1 but not T cell immunoglobulin and mucin-domain containing-3 (Tim-3) at an activated state of early tumor-infiltrating CD8(+) T cells, and B7S1 promoted T cell exhaustion, possibly through Eomes overexpression. Combinatorial blockade of B7S1 and PD-1 synergistically enhanced anti-tumor immune responses. Collectively, B7S1 initiates dysfunction of tumor-infiltrating CD8(+) T cells and may be targeted for cancer immunotherapy.
in vivo blocking of PD-1/PD-L signaling
Li, C., et al. (2015). "ADAP and SKAP55 deficiency suppresses PD-1 expression in CD8+ cytotoxic T lymphocytes for enhanced anti-tumor immunotherapy" EMBO Mol Med 7(6): 754-769. PubMed
PD-1 negatively regulates CD8(+) cytotoxic T lymphocytes (CTL) cytotoxicity and anti-tumor immunity. However, it is not fully understood how PD-1 expression on CD8(+) CTL is regulated during anti-tumor immunotherapy. In this study, we have identified that the ADAP-SKAP55 signaling module reduced CD8(+) CTL cytotoxicity and enhanced PD-1 expression in a Fyn-, Ca(2+)-, and NFATc1-dependent manner. In DC vaccine-based tumor prevention and therapeutic models, knockout of SKAP55 or ADAP showed a heightened protection from tumor formation or metastases in mice and reduced PD-1 expression in CD8(+) effector cells. Interestingly, CTLA-4 levels and the percentages of tumor infiltrating CD4(+)Foxp3(+) Tregs remained unchanged. Furthermore, adoptive transfer of SKAP55-deficient or ADAP-deficient CD8(+) CTLs significantly blocked tumor growth and increased anti-tumor immunity. Pretreatment of wild-type CD8(+) CTLs with the NFATc1 inhibitor CsA could also downregulate PD-1 expression and enhance anti-tumor therapeutic efficacy. Together, we propose that targeting the unrecognized ADAP-SKAP55-NFATc1-PD-1 pathway might increase efficacy of anti-tumor immunotherapy.
in vivo blocking of PD-1/PD-L signaling
Imai, Y., et al. (2015). "Cutting Edge: PD-1 Regulates Imiquimod-Induced Psoriasiform Dermatitis through Inhibition of IL-17A Expression by Innate gammadelta-Low T Cells" J Immunol 195(2): 421-425. PubMed
Programmed cell death 1 (PD-1) is a key regulatory molecule that has been targeted in human cancers, including melanoma. In clinical testing, Abs against PD-1 have resulted in psoriasiform dermatitis (PsD). To determine whether PD-1 regulates PsD, we compared skin responses of PD-1-deficient (PD-1KO) mice and wild-type (WT) controls in an imiquimod (IMQ)-induced murine model of psoriasis. PD-1KO mice showed severe epidermal hyperplasia, greater neutrophilic infiltration, and higher expression of Th17 cytokines (versus WT mice). IMQ exposure increased PD-1 expression by skin gammadelta-low (GDL) T cells and enhanced expression of PD-L1 by keratinocytes. Three-fold increases in the percentage of IL-17A(+) GDL T cells were observed in skin cell suspensions derived from IMQ-treated PD-1KO mice (versus WT controls), suggesting that the lack of PD-1 has a functional effect not only on alphabeta T cells, but also on GDL T cells, and that PD-1 may play a regulatory role in PsD.
in vitro PD-1 neutralization
Verhagen, J. and D. C. Wraith. (2014). "Blockade of LFA-1 augments in vitro differentiation of antigen-induced Foxp3(+) Treg cells" J Immunol Methods 414: 58-64. PubMed
Adoptive transfer of antigen-specific, in vitro-induced Foxp3(+) Treg (iTreg) cells protects against autoimmune disease. To generate antigen-specific iTreg cells at high purity, however, remains a challenge. Whereas polyclonal T cell stimulation with anti-CD3 and anti-CD28 antibody yields Foxp3(+) iTreg cells at a purity of 90-95%, antigen-induced iTreg cells typically do not exceed a purity of 65-75%, even in a TCR-transgenic model. In a similar vein to thymic Treg cell selection, iTreg cell differentiation is influenced not only by antigen recognition and the availability of TGF-beta but also by co-factors including costimulation and adhesion molecules. In this study, we demonstrate that blockade of the T cell integrin Leukocyte Function-associated Antigen-1 (LFA-1) during antigen-mediated iTreg cell differentiation augments Foxp3 induction, leading to approximately 90% purity of Foxp3(+) iTreg cells. This increased efficacy not only boosts the yield of Foxp3(+) iTreg cells, it also reduces contamination with activated effector T cells, thus improving the safety of adoptive transfer immunotherapy.
in vivo blocking of PD-1/PD-L signaling
Rabenstein, H., et al. (2014). "Differential kinetics of antigen dependency of CD4+ and CD8+ T cells" J Immunol 192(8): 3507-3517. PubMed
Ag recognition via the TCR is necessary for the expansion of specific T cells that then contribute to adaptive immunity as effector and memory cells. Because CD4+ and CD8+ T cells differ in terms of their priming APCs and MHC ligands we compared their requirements of Ag persistence during their expansion phase side by side. Proliferation and effector differentiation of TCR transgenic and polyclonal mouse T cells were thus analyzed after transient and continuous TCR signals. Following equally strong stimulation, CD4+ T cell proliferation depended on prolonged Ag presence, whereas CD8+ T cells were able to divide and differentiate into effector cells despite discontinued Ag presentation. CD4+ T cell proliferation was neither affected by Th lineage or memory differentiation nor blocked by coinhibitory signals or missing inflammatory stimuli. Continued CD8+ T cell proliferation was truly independent of self-peptide/MHC-derived signals. The subset divergence was also illustrated by surprisingly broad transcriptional differences supporting a stronger propensity of CD8+ T cells to programmed expansion. These T cell data indicate an intrinsic difference between CD4+ and CD8+ T cells regarding the processing of TCR signals for proliferation. We also found that the presentation of a MHC class II-restricted peptide is more efficiently prolonged by dendritic cell activation in vivo than a class I bound one. In summary, our data demonstrate that CD4+ T cells require continuous stimulation for clonal expansion, whereas CD8+ T cells can divide following a much shorter TCR signal.
in vivo blocking of PD-1/PD-L signaling
Sarraj, B., et al. (2014). "Impaired selectin-dependent leukocyte recruitment induces T-cell exhaustion and prevents chronic allograft vasculopathy and rejection" Proc Natl Acad Sci U S A 111(33): 12145-12150. PubMed
Selectin-selectin ligand interactions mediate the initial steps in leukocyte migration, an integral part of immune responses. Fucosyltransferase-VII (FucT-VII), encoded by Fut7, is essential for biosynthesis of selectin ligands. In an established model of cardiac allograft vasculopathy and chronic rejection, Fut7(-/-) recipients exhibited long-term graft survival with minimal vasculopathy compared with WT controls. Graft survival was associated with CD4 T-cell exhaustion in the periphery, characterized by impaired effector cytokine production, defective proliferation, increased expression of inhibitory receptors programmed death-1 (PD-1) and T cell Ig- and mucin-domain-containing molecule-3 (Tim-3), low levels of IL-7Ralpha on CD4 T cells, and reduced migration of polyfunctional CD4 memory T cells to the allograft. Blocking PD-1 triggered rejection only in Fut7(-/-) recipients, whereas depleting regulatory T cells had no effect in either Fut7(-/-) or WT recipients. Adoptive transfer experiments confirmed that this CD4 T cell-exhausted phenotype is seen primarily in Fut7(-/-) CD4 T cells. These data suggest that impaired leukocyte recruitment is a novel mechanism leading to CD4 T-cell exhaustion. Our experimental system serves as an excellent model to study CD4 T-cell exhaustion as a dominant mechanism of transplant tolerance. Further, targeting FucT-VII may serve as a promising strategy to prevent chronic allograft rejection and promote tolerance.
in vivo blocking of PD-1/PD-L signaling
Van der Jeught, K., et al. (2014). "Intratumoral administration of mRNA encoding a fusokine consisting of IFN-beta and the ectodomain of the TGF-beta receptor II potentiates antitumor immunity" Oncotarget 5(20): 10100-10113. PubMed
It is generally accepted that the success of immunotherapy depends on the presence of tumor-specific CD8(+) cytotoxic T cells and the modulation of the tumor environment. In this study, we validated mRNA encoding soluble factors as a tool to modulate the tumor microenvironment to potentiate infiltration of tumor-specific T cells. Intratumoral delivery of mRNA encoding a fusion protein consisting of interferon-beta and the ectodomain of the transforming growth factor-beta receptor II, referred to as Fbeta(2), showed therapeutic potential. The treatment efficacy was dependent on CD8(+) T cells and could be improved through blockade of PD-1/PD-L1 interactions. In vitro studies revealed that administration of Fbeta(2) to tumor cells resulted in a reduced proliferation and increased expression of MHC I but also PD-L1. Importantly, Fbeta(2) enhanced the antigen presenting capacity of dendritic cells, whilst reducing the suppressive activity of myeloid-derived suppressor cells. In conclusion, these data suggest that intratumoral delivery of mRNA encoding soluble proteins, such as Fbeta(2), can modulate the tumor microenvironment, leading to effective antitumor T cell responses, which can be further potentiated through combination therapy.
in vivo blocking of PD-1/PD-L signaling, in vitro PD-1 neutralization
Park, S. J., et al. (2014). "Negative role of inducible PD-1 on survival of activated dendritic cells" J Leukoc Biol 95(4): 621-629. PubMed
PD-1 is a well-established negative regulator of T cell responses by inhibiting proliferation and cytokine production of T cells via interaction with its ligands, B7-H1 (PD-L1) and B7-DC (PD-L2), expressed on non-T cells. Recently, PD-1 was found to be expressed in innate cells, including activated DCs, and plays roles in suppressing production of inflammatory cytokines. In this study, we demonstrate that PD-1 KO DCs exhibited prolonged longevity compared with WT DCs in the dLNs after transfer of DCs into hind footpads. Interestingly, upon LPS stimulation, WT DCs increased the expression of PD-1 and started to undergo apoptosis. DCs, in spleen of LPS-injected PD-1 KO mice, were more resistant to LPS-mediated apoptosis in vivo than WT controls. Moreover, treatment of blocking anti-PD-1 mAb during DC maturation resulted in enhanced DC survival, suggesting that PD-1:PD-L interactions are involved in DC apoptosis. As a result, PD-1-deficient DCs augmented T cell responses in terms of antigen-specific IFN-gamma production and proliferation of CD4 and CD8 T cells to a greater degree than WT DCs. Moreover, PD-1 KO DCs exhibited increased MAPK1 and CD40-CD40L signaling, suggesting a possible mechanism for enhanced DC survival in the absence of PD-1 expression. Taken together, our findings further extend the function of PD-1, which plays an important role in apoptosis of activated DCs and provides important implications for PD-1-mediated immune regulation.
in vitro PD-1 neutralization
Schwager, K., et al. (2013). "The immunocytokine L19-IL2 eradicates cancer when used in combination with CTLA-4 blockade or with L19-TNF" J Invest Dermatol 133(3): 751-758. PubMed
Systemic high-dose IL2 promotes long-term survival in a subset of metastatic melanoma patients, but this treatment is accompanied by severe toxicities. The immunocytokine L19-IL2, in which IL2 is fused to the human L19 antibody capable of selective accumulation on tumor neovasculature, has recently shown encouraging clinical activity in patients with metastatic melanoma. In this study, we have investigated the therapeutic performance of L19-IL2, administered systemically in combination with a murine anti-CTLA-4 antibody or with a second clinical-stage immunocytokine (L19-TNF) in two syngeneic immunocompetent mouse models of cancer. We observed complete tumor eradications when L19-IL2 was used in combination with CTLA-4 blockade. Interestingly, mice cured from F9 tumors developed new lesions when rechallenged with tumor cells after therapy, whereas mice cured from CT26 tumors were resistant to tumor rechallenge. Similarly, L19-IL2 induced complete remissions when administered in a single intratumoral injection in combination with L19-TNF, whereas the two components did not lead to cures when administered as single agents. These findings provide a rationale for combination trials in melanoma, as the individual therapeutic agents have been extensively studied in clinical trials, and the antigen recognized by the L19 antibody has an identical sequence in mouse and man.
in vitro PD-1 neutralization
Noval Rivas, M., et al. (2009). "Reviving function in CD4+ T cells adapted to persistent systemic antigen" J Immunol 183(7): 4284-4291. PubMed
In bone marrow-transplanted patients, chronic graft-versus-host disease is a complication that results from the persistent stimulation of recipient minor histocompatibility Ag (mHA)-specific T cells contained within the graft. In this study, we developed a mouse model where persistent stimulation of donor T cells by recipientās mHA led to multiorgan T cell infiltration. Exposure to systemic mHA, however, deeply modified T cell function and chronically stimulated T cells developed a long-lasting state of unresponsiveness, or immune adaptation, characterized by their inability to mediate organ immune damages in vivo. However, analysis of the gene expression profile of adapted CD4+ T cells revealed the specific coexpression of genes known to promote differentiation and function of Th1 effector cells as well as genes coding for proteins that control T cell activity, such as cell surface-negative costimulatory molecules and regulatory cytokines. Strikingly, blockade of negative costimulation abolished T cell adaptation and stimulated strong IFN-gamma production and severe multiorgan wasting disease. Negative costimulation was also shown to control lethal LPS-induced toxic shock in mice with adapted T cells, as well as the capacity of adapted T cells to reject skin graft. Our results demonstrate that negative costimulation is the molecular mechanism used by CD4+ T cells to adapt their activity in response to persistent antigenic stimulation. The effector function of CD4+ T cells that have adapted to chronic Ag presentation can be activated by stimuli strong enough to overcome regulatory signals delivered to the T cells by negative costimulation.
- Immunology and Microbiology,
PD-1 Impairs CD8+ T Cell Granzyme B Production in Aged Mice during Acute Viral Respiratory Infection.
In ImmunoHorizons on 1 November 2023 by Parks, O. B., Antos, D., et al.
PubMed
CD8+ T cell dysfunction contributes to severe respiratory viral infection outcomes in older adults. CD8+ T cells are the primary cell type responsible for viral clearance. With increasing age, CD8+ T cell function declines in conjunction with an accumulation of cytotoxic tissue-resident memory (TRM) CD8+ T cells. We sought to elucidate the role of PD-1 signaling on aged CD8+ T cell function and accumulation of CD8+ TRM cells during acute viral respiratory tract infection, given the importance of PD-1 regulating CD8+ T cells during acute and chronic infections. PD-1 blockade or genetic ablation in aged mice yielded improved CD8+ T cell granzyme B production comparable to that in young mice during human metapneumovirus and influenza viral infections. Syngeneic transplant and adoptive transfer strategies revealed that improved granzyme B production in aged Pdcd1-/- CD8+ T cells was primarily cell intrinsic because aged wild-type CD8+ T cells did not have increased granzyme B production when transplanted into a young host. PD-1 signaling promoted accumulation of cytotoxic CD8+ TRM cells in aged mice. PD-1 blockade of aged mice during rechallenge infection resulted in improved clinical outcomes that paralleled reduced accumulation of CD8+ TRM cells. These findings suggest that PD-1 signaling impaired CD8+ T cell granzyme B production and contributed to CD8+ TRM cell accumulation in the aged lung. These findings have implications for future research investigating PD-1 checkpoint inhibitors as a potential therapeutic option for elderly patients with severe respiratory viral infections. Copyright Ā© 2023 The Authors.
- Mus musculus (House mouse),
- Immunology and Microbiology,
- Stem Cells and Developmental Biology
Reciprocal transmission of activating and inhibitory signals and cell fate in regenerating TĀ cells.
In Cell Reports on 31 October 2023 by Wang, P. H., Washburn, R. S., et al.
PubMed
The ability of activated progenitor TĀ cells to self-renew while producing differentiated effector cell descendants may underlie immunological memory and persistent responses to ongoing infection. The nature of stem-like TĀ cells responding to cancer and during treatment with immunotherapy is not clear. The subcellular organization of dividing progenitor CD8+ TĀ cells from mice challenged with syngeneic tumors is examined here. Three-dimensional microscopy reveals an activating hub composed of polarized CD3, CD28, and phosphatidylinositol 3-kinase (PI3K) activity at the putative immunological synapse with an inhibitory hub composed of polarized PD-1 and CD73 at the opposite pole of mitotic blasts. Progenitor TĀ cells from untreated and inhibitory checkpoint blockade-treated mice yield a differentiated TCF1- daughter cell, which inherits the PI3K activation hub, alongside a discordantly fated, self-renewing TCF1+ sister cell. Dynamic organization of opposite activating and inhibitory signaling poles in mitotic lymphocytes may account for the enigmatic durability of specific immunity. Copyright Ā© 2023 The Author(s). Published by Elsevier Inc. All rights reserved.
- Cancer Research,
- Immunology and Microbiology
Synergism Between IL21 and Anti-PD-1 Combination Therapy is Underpinned by the Coordinated Reprogramming of the Immune Cellular Network in the Tumor Microenvironment.
In Cancer Res Commun on 1 August 2023 by Wu, S., Huang, H., et al.
PubMed
T cell-stimulating cytokines and immune checkpoint inhibitors (ICI) are an ideal combination for increasing response rates of cancer immunotherapy. However, the results of clinical trials have not been satisfying. It is important to understand the mechanism of synergy between these two therapeutic modalities. Here, through integrated analysis of multiple single-cell RNA sequencing (scRNA-seq) datasets of human tumor-infiltrating immune cells, we demonstrate that IL21 is produced by tumor-associated T follicular helper cells and hyperactivated/exhausted CXCL13+CD4+ T cells in the human tumor microenvironment (TME). In the mouse model, the hyperactivated/exhausted CD4+ T cell-derived IL21 enhances the helper function of CD4+ T cells that boost CD8+ T cell-mediated immune responses during PD-1 blockade immunotherapy. In addition, we demonstrated that IL21's antitumor activity did not require T-cell trafficking. Using scRNA-seq analysis of the whole tumor-infiltrating immune cells, we demonstrated that IL21 treatment in combination with anti-PD-1 blockade synergistically drives tumor antigen-specific CD8+ T cells to undergo clonal expansion and differentiate toward the hyperactive/exhausted functional state in the TME. In addition, IL21 treatment and anti-PD-1 blockade synergistically promote dendritic cell (DC) activation and maturation to mature DC as well as monocyte to type 1 macrophage (M1) differentiation in the TME. Furthermore, the combined treatment reprograms the immune cellular network by reshaping cell-cell communication in the TME. Our study establishes unique mechanisms of synergy between IL21 and PD-1-based ICI in the TME through the coordinated promotion of type 1 immune responses. This study reveals how cytokine and checkpoint inhibitor therapy can be combined to increase the efficacy of cancer immunotherapy. Ā© 2023 The Authors; Published by the American Association for Cancer Research.
- Immunology and Microbiology,
- Cancer Research
The GPCR-GĪ±s-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 GĪ±s-coupled GPCRs on exhausted CD8+ T cells. These include EP2, EP4, A2AR, Ī²1AR and Ī²2AR, all of which promote T cell dysfunction. We also developed transgenic mice expressing a chemogenetic CD8-restricted GĪ±s-DREADD to activate CD8-restricted GĪ±s signaling and show that a GĪ±s-PKA signaling axis promotes CD8+ T cell dysfunction and immunotherapy failure. These data indicate that GĪ±s-GPCRs are druggable immune checkpoints that might be targeted to enhance the response to ICB immunotherapies. Ā© 2023. The Author(s), under exclusive licence to Springer Nature America, Inc.
- Cancer Research,
- Immunology and Microbiology
Nigericin Boosts Anti-Tumor Immune Response via Inducing Pyroptosis in Triple-Negative Breast Cancer.
In Cancers on 16 June 2023 by Wu, L., Bai, S., et al.
PubMed
Although immune checkpoint inhibitors improved the clinical outcomes of advanced triple negative breast cancer (TBNC) patients, the response rate remains relatively low. Nigericin is an antibiotic derived from Streptomyces hydrophobicus. We found that nigericin caused cell death in TNBC cell lines MDA-MB-231 and 4T1 by inducing concurrent pyroptosis and apoptosis. As nigericin facilitated cellular potassium efflux, we discovered that it caused mitochondrial dysfunction, leading to mitochondrial ROS production, as well as activation of Caspase-1/GSDMD-mediated pyroptosis and Caspase-3-mediated apoptosis in TNBC cells. Notably, nigericin-induced pyroptosis could amplify the anti-tumor immune response by enhancing the infiltration and anti-tumor effect of CD4+ and CD8+ T cells. Moreover, nigericin showed a synergistic therapeutic effect when combined with anti-PD-1 antibody in TNBC treatment. Our study reveals that nigericin may be a promising anti-tumor agent, especially in combination with immune checkpoint inhibitors for advanced TNBC treatment.
- Mus musculus (House mouse)
Human Metapneumovirus Reinfection in Aged Mice Recapitulates Increased Disease Severity in Elderly Humans Infected with Human Metapneumovirus.
In ImmunoHorizons on 1 June 2023 by Parks, O. B., Eddens, T., et al.
PubMed
Human metapneumovirus (HMPV) is a leading cause of respiratory infection in adults >65 y. Nearly all children worldwide are seropositive for HMPV by age 5 y, but reinfections occur throughout life, and there is no licensed vaccine. Recurrent HMPV infection is mild and self-resolving in immunocompetent individuals. However, elderly individuals develop severe respiratory disease on HMPV reinfection that leads to a high risk for morbidity and mortality. In this study, we developed a mouse model to mirror HMPV reinfection in elderly humans. C57BL/6J mice were infected with HMPV at 6-7 wk old, aged in-house, and rechallenged with high-dose virus at 70 wk. Aged rechallenged mice had profound weight loss similar to primary infected mice, increased lung histopathology, and accumulated cytotoxic CD8+CD44+CD62L-CD69+CD103+ memory cells despite having undetectable lung virus titer. When aged mice 14 mo postinfection (p.i.) or young mice 5 wk p.i. were restimulated with HMPV cognate Ag to mimic epitope vaccination, aged mice had an impaired CD8+ memory response. Convalescent serum transfer from young naive or 5 wk p.i. mice into aged mice on day of infection did not protect. Aged mice vaccinated with UV-inactivated HMPV also exhibited diminished protection and poor CD8+ memory response compared with young mice. These results suggest aged individuals with HMPV reinfection have a dysregulated CD8+ memory T cell response that fails to protect and exacerbates disease. Moreover, aged mice exhibited a poor memory response to either epitope peptide or UV-inactivated vaccination, suggesting that aged CD8+ T cell dysfunction presents a barrier to effective vaccination strategies. Copyright Ā© 2023 The Authors.
- FC/FACS,
- Cancer Research,
- Immunology and Microbiology,
- Mus musculus (House mouse)
Endosialin-positive tumor-derived pericytes promote tumor progression through impeding the infiltration of CD8+ T cells in clear cell renal cell carcinoma.
In Cancer Immunology, Immunotherapy : CII on 1 June 2023 by Lu, T., Zhang, J., et al.
PubMed
Immune checkpoint blockade (ICB) therapy can be effective against clear cell renal cell carcinoma (ccRCC), but many patients show no benefit. Tumor-derived pericytes (TDPs) may promote tumor progression by influencing T cells and are an immunotherapy target; however, they may comprise functionally distinct subtypes. We aimed to identify markers of tumor-promoting TDPs and develop TDP-targeting strategies to enhance ICB therapy effectiveness against ccRCC. We analyzed the relationship between endosialin (EN) expression and cytotoxic T-lymphocyte (CTL) infiltration in ccRCC tumor samples using flow cytometry and in a ccRCC-bearing mice inhibited for EN via knockout or antibody-mediated blockade. The function of ENhigh TDPs in CTL infiltration and tumor progression was analyzed using RNA-sequencing (RNA-seq) data from ccRCC tissue-derived TDPs and single-cell RNA-seq (scRNA-seq) data from an online database. The role of EN in TDP proliferation and migration and in CTL infiltration was examined in vitro. Finally, we examined the anti-tumor effect of combined anti-EN and anti-programmed death 1 (PD-1) antibodies in ccRCC-bearing mice. High EN expression was associated with low CTL infiltration in ccRCC tissues, and inhibition of EN significantly increased CTL infiltration in ccRCC-bearing mice. RNA-seq and scRNA-seq analyses indicated that high EN expression represented the TDP activation state. EN promoted TDP proliferation and migration and impeded CTL infiltration in vitro. Finally, combined treatment with anti-EN and anti-PD-1 antibodies synergistically enhanced anti-tumor efficacy. ENhigh TDPs are in an activated state and inhibit CTL infiltration into ccRCC tissues. Combined treatment with anti-EN and anti-PD-1 antibodies may improve ICB therapy effectiveness against ccRCC. Ā© 2023. The Author(s).
- Cancer Research,
- Immunology and Microbiology,
- In Vivo,
- Mus musculus (House mouse)
Arginase 1 is a key driver of immune suppression in pancreatic cancer.
In eLife on 2 February 2023 by Menjivar, R. E., Nwosu, Z. C., et al.
PubMed
An extensive fibroinflammatory stroma rich in macrophages is a hallmark of pancreatic cancer. In this disease, it is well appreciated that macrophages are immunosuppressive and contribute to the poor response to immunotherapy; however, the mechanisms of immune suppression are complex and not fully understood. Immunosuppressive macrophages are classically defined by the expression of the enzyme Arginase 1 (ARG1), which we demonstrated is potently expressed in pancreatic tumor-associated macrophages from both human patients and mouse models. While routinely used as a polarization marker, ARG1 also catabolizes arginine, an amino acid required for T cell activation and proliferation. To investigate this metabolic function, we used a genetic and a pharmacologic approach to target Arg1 in pancreatic cancer. Genetic inactivation of Arg1 in macrophages, using a dual recombinase genetically engineered mouse model of pancreatic cancer, delayed formation of invasive disease, while increasing CD8+ T cell infiltration. Additionally, Arg1 deletion induced compensatory mechanisms, including Arg1 overexpression in epithelial cells, namely Tuft cells, and Arg2 overexpression in a subset of macrophages. To overcome these compensatory mechanisms, we used a pharmacological approach to inhibit arginase. Treatment of established tumors with the arginase inhibitor CB-1158 exhibited further increased CD8+ T cell infiltration, beyond that seen with the macrophage-specific knockout, and sensitized the tumors to anti-PD1 immune checkpoint blockade. Our data demonstrate that Arg1 drives immune suppression in pancreatic cancer by depleting arginine and inhibiting T cell activation. Ā© 2023, Menjivar et al.
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Notch signaling regulates immunosuppressive tumor-associated macrophage function in pancreatic cancer
Preprint on BioRxiv : the Preprint Server for Biology on 13 January 2023 by Yan, W., Steele, N. G., et al.
PubMed
Pancreatic ductal adenocarcinoma (PDA) continues to have a dismal prognosis. The poor survival of patients with PDA has been attributed to a high rate of early metastasis and low efficacy of current therapies, which partly result from its complex immunosuppressive tumor microenvironment. Previous studies from our group and others have shown that tumor-associated macrophages (TAMs) are instrumental in maintaining immunosuppression in PDA. Here, we explored the role of Notch signaling, a key regulator of immune response, within the PDA microenvironment. We identified Notch pathway components in multiple immune cell types within human and mouse pancreatic cancer. TAMs, the most abundant immune cell population in the tumor microenvironment, express high levels of Notch receptors with cognate ligands such as JAG1 expressed on tumor epithelial cells, endothelial cells and fibroblasts. TAMs with activated Notch signaling expressed higher levels of immunosuppressive mediators including arginase 1 ( Arg1 ) suggesting that Notch signaling plays a role in macrophage polarization within the PDA microenvironment. Combination of Notch inhibition with PD-1 blockade resulted in increased cytotoxic T cell infiltration, tumor cell apoptosis, and smaller tumor size. Our work implicates macrophage Notch signaling in the establishment of immunosuppression and indicates that targeting the Notch pathway may improve the efficacy of immune-based therapies in PDA patients.
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Host stimulator of interferon genes is essential for the efficacy of anti-programmed cell death protein 1 inhibitors in non-small cell lung cancer.
In Immunology on 1 December 2022 by Zhou, L., Xu, Q., et al.
PubMed
The stimulator of interferon genes (STING) pathway is important for anticancer immune responses. However, the relative contributions of host and tumour STING in anti-programmed cell death protein 1 (anti-PD-1) inhibitor responses in non-small cell lung cancer (NSCLC) are unknown. STING expression in tumour and blood was associated with anti-PD-1 therapy in NSCLC patients; Moreover, loss of PD-1 inhibitor therapeutic potency was demonstrated in STING KO (knock out)Ā splenocytes and STING KO mice. STING knock-down in tumour cells had no effect. STING on CD8+ T cells and host cells, not tumour cells, correlated with clinical effect of anti-PD-1 therapy in NSCLC patients. Finally, adoptive transfer of CD8+ T cells restored PD-1 inhibitor anticancer effects. STING in host cells but not in tumour cells mediates anti-PD-1 inhibitor responses in cancer immunotherapy and could be used to select advantageous NSCLC patients from immunotherapy. Ā© 2022 John Wiley Sons Ltd.
- IHC,
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Targeting the CD47/thrombospondin-1 signaling axis regulates immune cell bioenergetics in the tumor microenvironment to potentiate antitumor immune response.
In Journal for Immunotherapy of Cancer on 1 November 2022 by Stirling, E. R., Terabe, M., et al.
PubMed
CD47 is an integral membrane protein that alters adaptive immunosurveillance when bound to the matricellular glycoprotein thrombospondin-1 (TSP1). We examined the impact of the CD47/TSP1 signaling axis on melanoma patient response to anti-PD-1 therapy due to alterations in T cell activation, proliferation, effector function, and bioenergetics. A syngeneic B16 mouse melanoma model was performed to determine if targeting CD47 as monotherapy or in combination with anti-PD-1 impacted tumor burden. Cytotoxic (CD8+) T cells from Pmel-1 transgenic mice were used for T cell activation, cytotoxic T lymphocyte, and cellular bioenergetic assays. Single-cell RNA-sequencing, ELISA, and flow cytometry was performed on peripheral blood mononuclear cells and plasma of melanoma patients receiving anti-PD-1 therapy to examine CD47/TSP1 expression. Human malignant melanoma tissue had increased CD47 and TSP1 expression within the tumor microenvironment compared with benign tissue. Due to the negative implications CD47/TSP1 can have on antitumor immune responses, we targeted CD47 in a melanoma model and observed a decrease in tumor burden due to increased tumor oxygen saturation and granzyme B secreting CD8+ T cells compared with wild-type tumors. Additionally, Pmel-1 CD8+ T cells exposed to TSP1 had reduced activation, proliferation, and effector function against B16 melanoma cells. Targeting CD47 allowed CD8+ T cells to overcome this TSP1 interaction to sustain these functions. TSP1 exposed CD8+ T cells have a decreased rate of glycolysis; however, targeting CD47 restored glycolysis when CD8+ T cells were exposed to TSP1, suggesting CD47 mediated metabolic reprogramming of T cells. Additionally, non-responding patients to anti-PD-1 therapy had increased T cells expressing CD47 and circulating levels of TSP1 compared with responding patients. Since CD47/TSP1 signaling axis negatively impacts CD8+ T cells and non-responding patients to anti-PD-1 therapy have increased CD47/TSP1 expression, we targeted CD47 in combination with anti-PD-1 in a melanoma model. Targeting CD47 in combination with anti-PD-1 treatment further decreased tumor burden compared with monotherapy and control. CD47/TSP1 expression could serve as a marker to predict patient response to immune checkpoint blockade treatment, and targeting this pathway may preserve T cell activation, proliferation, effector function, and bioenergetics to reduce tumor burden as a monotherapy or in combination with anti-PD-1. Ā© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
FBW7-mediated ubiquitination and destruction of PD-1 protein primes sensitivity to anti-PD-1 immunotherapy in non-small cell lung cancer.
In Journal for Immunotherapy of Cancer on 1 September 2022 by Liu, J., Wei, L., et al.
PubMed
Activation of the programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) pathway has been extensively described as a pivotal mechanism to escape immune surveillance and elicits suppressive effect on antitumor immunity. Blockade of the PD-1/PD-L1 interaction by checkpoint inhibitors has been shown to result in tumor shrinkage and prolong patient survival. However, regulatory machinery for PD-1/PD-L1 expression is largely unknown. We used bioinformatic tools and biochemical methods to investigate the significance of F-box and WD repeat domain containing 7 (FBW7) in regulating PD-1 protein stability. By generating a panel of FBW7 and PD-1 encoding plasmids, we expressed FBW7 and PD-1 or their mutants to performed immunoprecipitation and immunoblotting assays. The efficacy of cotargeting FBW7 to enhance antitumor immunity was evaluated in C57BL/6J mice. These laboratory findings were further validated in tumor samples obtained from patients with non-small cell lung cancer (NSCLC). We identified FBW7 as a E3 ubiquitin ligase for PD-1 protein, in which FBW7 promotes the K48-linked polyubiquitination of PD-1 protein at Lys233 residue. Cotargeting FBW7 accelerates PD-1 protein degradation and enhances antitumor immunity in vivo. Moreover, we demonstrated that cyclin-dependent kinase 1-mediated phosphorylation of Ser261 residue primes PD-1 protein nucleus translocation and binding with FBW7. Higher expression of FBW7 characterizes a 'hot' tumor microenvironment and confers more favorable responses to PD-1 blockade therapy. This study highlights the critical role of FBW7 in determining PD-1 protein stability. FBW7 ubiquitinates PD-1 in a phosphorylation-dependent manner, as a consequence, leading to PD-1 protein degradation and cytotoxic lymphocytes infiltrating the tumor microenvironment. Screening FBW7 status would predict clinical response to anti-PD-1 immunotherapy in patients with NSCLC, and targeting FBW7 is a promising strategy to enhance antitumor immunity. Ā© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
- Cancer Research,
- Immunology and Microbiology
Endosialin positive tumor derived pericytes promote tumor progression through impeding the infiltration of CD8 + T cells in clear cell renal cell carcinoma
Preprint on Research Square on 5 August 2022 by Lu, T., Zhang, J., et al.
PubMed
h4>Background: /h4> Clear cell renal cell carcinoma (ccRCC) is considered to be an immunogenic tumor, and immune checkpoint blockade (ICB) therapy provides effective option for RCC treatment. However, a large proportion of patients do not benefit from ICB therapy. Tumor derived pericytes (TDPs) are an important component in tumor microenvironment (TME), and may promote tumor progression through the regulation on T cells. TDPs has been considered as ideal target for tumor treatment. However, like CAFs, TDPs are also heterogeneous, different subclusters may have distinct function. Here, we aimed to identify new specific marker for tumor promoting TDPs and to develop novel TDPs targeting therapeutic strategies to enhance the efficacy of ICB therapy in ccRCC. h4>Methods: /h4> To analyze the relationship between endosialin (EN) expression and the infiltration of CD8 + T cells in ccRCC, we performed flow cytometry using freshly isolated tumor specimens from ccRCC patients. Then, their correlation was verified in ccRCC-bearing wildtype and endosialin knockout mice, and also by antibody mediated blockade of endosialin. RNA-sequencing (RNA-seq) using EN-high and EN-low TDPs from ccRCC tissues and published single-cell RNA-sequencing (scRNA-seq) data of ccRCC were analyzed to figure out the potential functions of EN-high TDPs in CD8 + T cell infiltration and tumor progression. Function of endosialin in the regulation of cell proliferation and migration of TDPs, and CD8 + T cells infiltration was examined in vitro . Combined treatment with endosialin antibody and PD-1 blockade was applied to treat ccRCC-bearing mice and the anti-tumor effect was examined. h4>Results: /h4> We found that high endosialin expression was associated with low infiltration of CD8 + T cells in clinical ccRCC tissues. Endosialin knockout or antibody blockade could significantly increase the infiltration of CD8 + T cells in ccRCC-bearing model. RNA-seq and scRNA-seq analysis indicated that high EN-high TDPs represent an activated state of TDPs. We also demonstrated that endosialin could promote the proliferation and migration of TDPs and impede the infiltration of CD8 + T cells in vitro . At last, we showed that combined treatment with anti-endosialin antibody could enhance the anti-tumor efficacy of PD-1 blockade. h4>Conclusion: /h4> We reported EN-high TDPs represent an activated state of TDPs and inhibit the infiltration of CD8 + T cells into ccRCC tissues. Combined treatment with anti-endosialin antibody and PD-1 antibody provided a rational strategy to improve effect of ICB therapy in ccRCC.
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Arginase 1 is a key driver of immune suppression in pancreatic cancer
Preprint on BioRxiv : the Preprint Server for Biology on 24 June 2022 by Menjivar, R. E., Nwosu, Z. C., et al.
PubMed
An extensive fibroinflammatory stroma rich in macrophages is a hallmark of pancreatic cancer. In this disease, it is well appreciated that macrophages are immunosuppressive and contribute to the poor response to immunotherapy; however, the mechanisms of immune suppression are complex and not fully understood. Immunosuppressive macrophages are classically defined by expression of the enzyme Arginase 1 (Arg1), which we demonstrated is potently expressed in pancreatic tumor associated macrophages from both human patients and mouse models. While routinely used as a polarization marker, Arg1 also catabolizes arginine, an amino acid required for T cell activation and proliferation. To investigate this metabolic function, we used a genetic and a pharmacologic approach to target Arg1 in pancreatic cancer. Genetic inactivation of Arg1 in macrophages, using a dual recombinase genetically engineered mouse model of pancreatic cancer, delayed formation of invasive disease, while increasing CD8 + T cell infiltration. Treatment of established tumors with the arginase inhibitor CB-1158 exhibited further increased CD8 + T cell infiltration, beyond that seen with the macrophage-specific knockout, and sensitized the tumors to anti-PD1 immune checkpoint blockade. Thus, our data demonstrate that Arg1 is more than simply a marker of macrophage function. Rather, Arg1 is also a driver of immune suppression and represents a promising immunotherapeutic target for pancreatic cancer.
- Mus musculus (House mouse),
- Cancer Research,
- Immunology and Microbiology
Neuropilin-1 cooperates with PD-1 in CD8+ TĀ cells predicting outcomes in melanoma patients treated with anti-PD1.
In IScience on 17 June 2022 by Rossignol, J., Belaid, Z., et al.
PubMed
Targeting immune checkpoints, such as Programmed cell Death 1 (PD1), has improved survival in cancer patients by restoring antitumor immune responses. Most patients, however, relapse or are refractory to immune checkpoint blocking therapies. Neuropilin-1 (NRP1) is a transmembrane glycoprotein required for nervous system and angiogenesis embryonic development, also expressed in immune cells. We hypothesized that NRP1 could be an immune checkpoint co-receptor modulating CD8+ TĀ cells activity in the context of the antitumor immune response. Here, we show that NRP1 is recruited in the cytolytic synapse of PD1+CD8+ TĀ cells, cooperates and enhances PD-1 activity. In mice, CD8+ TĀ cells specific deletion of Nrp1 improves anti-PD1 antibody antitumor immune responses. Likewise, in human metastatic melanoma, the expression of NRP1 in tumor infiltrating CD8+ TĀ cells predicts poor outcome of patients treated with anti-PD1. NRP1 is a promising target to overcome resistance to anti-PD1 therapies.Ā© 2022.
- Biochemistry and Molecular biology,
- Cell Biology,
- Immunology and Microbiology
SENP7 senses oxidative stress to sustain metabolic fitness and antitumor functions of CD8+ T cells.
In The Journal of Clinical Investigation on 1 April 2022 by Wu, Z., Huang, H., et al.
PubMed
The functional integrity of CD8+ T cells is tightly coupled to metabolic reprogramming, but how oxidative stress directs CD8+ T cell metabolic fitness in the tumor microenvironment (TME) remains elusive. Here, we report that SUMO-specific protease 7 (SENP7) senses oxidative stress to maintain the CD8+ T cell metabolic state and antitumor functions. SENP7-deficient CD8+ T cells exhibited decreased glycolysis and oxidative phosphorylation, resulting in attenuated proliferation in vitro and dampened antitumor functions in vivo. Mechanistically, CD8+ T cell-derived ROS triggered cytosolic SENP7-mediated PTEN deSUMOylation, thereby promoting PTEN degradation and preventing PTEN-dependent metabolic defects. Importantly, lowering T cell-intrinsic ROS restricted SENP7 cytosolic translocation and repressed CD8+ T cell metabolic and functional activity in human colorectal cancer samples. Our findings reveal that SENP7, as an oxidative stress sensor, sustains CD8+ T cell metabolic fitness and effector functions and unveil an oxidative stress-sensing machinery in tumor-infiltrating CD8+ T cells.
The Tankyrase Inhibitor OM-153 Demonstrates Antitumor Efficacy and a Therapeutic Window in Mouse Models.
In Cancer Res Commun on 1 April 2022 by Waaler, J., Amundsen-Isaksen, E., et al.
PubMed
The catalytic enzymes tankyrase 1 and 2 (TNKS1/2) alter protein turnover by poly-ADP-ribosylating target proteins, which earmark them for degradation by the ubiquitin-proteasomal system. Prominent targets of the catalytic activity of TNKS1/2 include AXIN proteins, resulting in TNKS1/2 being attractive biotargets for addressing of oncogenic WNT/Ī²-catenin signaling. Although several potent small molecules have been developed to inhibit TNKS1/2, there are currently no TNKS1/2 inhibitors available in clinical practice. The development of tankyrase inhibitors has mainly been disadvantaged by concerns over biotarget-dependent intestinal toxicity and a deficient therapeutic window. Here we show that the novel, potent, and selective 1,2,4-triazole-based TNKS1/2 inhibitor OM-153 reduces WNT/Ī²-catenin signaling and tumor progression in COLO 320DM colon carcinoma xenografts upon oral administration of 0.33-10 mg/kg twice daily. In addition, OM-153 potentiates anti-programmed cell death protein 1 (anti-PD-1) immune checkpoint inhibition and antitumor effect in a B16-F10 mouse melanoma model. A 28-day repeated dose mouse toxicity study documents body weight loss, intestinal damage, and tubular damage in the kidney after oral-twice daily administration of 100 mg/kg. In contrast, mice treated oral-twice daily with 10 mg/kg show an intact intestinal architecture and no atypical histopathologic changes in other organs. In addition, clinical biochemistry and hematologic analyses do not identify changes indicating substantial toxicity. The results demonstrate OM-153-mediated antitumor effects and a therapeutic window in a colon carcinoma mouse model ranging from 0.33 to at least 10 mg/kg, and provide a framework for using OM-153 for further preclinical evaluations. This study uncovers the effectiveness and therapeutic window for a novel tankyrase inhibitor in mouse tumor models. Ā© 2022 The Authors; Published by the American Association for Cancer Research.
- Cancer Research,
- Immunology and Microbiology
Lacticaseibacillus paracasei sh2020 induced antitumor immunity and synergized with anti-programmed cell death 1 to reduce tumor burden in mice.
In Gut Microbes on 9 March 2022 by Zhang, S. L., Han, B., et al.
PubMed
The gut microbiota was emerging as critical regulatory elements in shaping the outcome of cancer immunotherapy. However, the underlying mechanisms by which the gut commensal species enhance antitumor immunity remain largely unexplored. Here, we show that the gut microbiota from healthy individuals conferred considerable sensitivity to anti-PD-1 in the colorectal cancer (CRC) tumor-bearing mice, whereas gut microbiota from CRC patients failed to do so. By 16S rRNA gene sequencing, we identified Lactobacillus that was significantly increased in the mice with good response to anti-PD-1, and significantly correlated with anti-tumor immunity. After a series of screening, we isolated a novel Lacticaseibacillus strain, named L. paracasei sh2020. L. paracasei sh2020 showed the most notable anti-tumor immunity in the mice with gut dysbiosis. Mechanistically, the antitumor immune response elicited by L. paracasei sh2020 was dependent on CD8+ T cell. In vitro and in vivo studies revealed that L. paracasei sh2020 stimulation triggered the upregulated expression of CXCL10 in the tumors and subsequently enhanced CD8+ T cell recruitment. Meanwhile, the modulation of gut microbiota caused by L. paracasei sh2020 enhanced its antitumor effect and gut barrier function. Overall, our study offered novel insights into the mechanism by which gut microbiota shaped the outcome of cancer immunotherapy and, more importantly, the novel strain L. paracasei sh2020 might serve as an easy and effective way to promote anti-PD-1 effect in clinical practice.
- In Vitro,
- Mus musculus (House mouse),
- Cancer Research
eEF2K promotes PD-L1 stabilization through inactivating GSK3Ī² in melanoma.
In Journal for Immunotherapy of Cancer on 1 March 2022 by Chen, X., Wang, K., et al.
PubMed
Immune checkpoint blockade (ICB) targeting programmed death ligand-1 (PD-L1)/programmed cell death protein-1 (PD-1) pathway has become an attractive strategy for cancer treatment; however, unsatisfactory efficacy has limited its clinical benefits. Therefore, a more comprehensive understanding of the regulation of PD-L1 expression is essential for developing more effective cancer immunotherapy. Recent studies have revealed the important roles of eukaryotic elongation factor 2 kinase (eEF2K) in promoting epithelial-mesenchymal transition (EMT), angiogenesis, tumor cell migration and invasion; nevertheless, the exact role of eEF2K in the regulation of tumor immune microenvironment (TIME) remains largely unknown. In this study, we used a cohort of 38 patients with melanoma who received anti-PD-1 treatment to explore the association between eEF2K expression and immunotherapy efficacy against melanoma. Immunoprecipitation-mass spectrometry analysis and in vitro assays were used to examine the role and molecular mechanism of eEF2K in regulating PD-L1 expression. We also determined the effects of eEF2K on tumor growth and cytotoxicity of CD8+ T cells in TIME in a mouse melanoma model. We further investigated the efficacy of the eEF2K inhibition in combination with anti-PD-1 treatment in vivo. High eEF2K expression is correlated with better therapeutic response and longer survival in patients with melanoma treated with PD-1 monoclonal antibody (mAb). Moreover, eEF2K protein expression is positively correlated with PD-L1 protein expression. Mechanistically, eEF2K directly bound to and inactivated glycogen synthase kinase 3 beta (GSK3Ī²) by phosphorylating it at serine 9 (S9), leading to PD-L1 protein stabilization and upregulation, and subsequently tumor immune evasion. Knockdown of eEF2K decreased PD-L1 expression and enhanced CD8+ T cell activity, thus dramatically attenuating murine B16F10 melanoma growth in vivo. Clinically, p-GSK3Ī²/S9 expression is positively correlated with the expressions of eEF2K and PD-L1, and the response to anti-PD-1 immunotherapy. Furthermore, eEF2K inhibitor, NH125 treatment or eEF2K knockdown enhanced the efficacy of PD-1 mAb therapy in a melanoma mouse model. Our results suggest that eEF2K may serve as a biomarker for predicting therapeutic response and prognosis in patients receiving anti-PD-1 therapy, reveal a vital role of eEF2K in regulating TIME by controlling PD-L1 expression and provide a potential combination therapeutic strategy of eEF2K inhibition with ICB therapy. Ā© Author(s) (or their employer(s)) 2022. Re-use permitted under CC BY. Published by BMJ.
- Mus musculus (House mouse),
- Immunology and Microbiology
Lymphatic-Preserving Treatment Sequencing with Immune Checkpoint Inhibition Unleashes cDC1-Dependent Antitumor Immunity in HNSCC
Preprint on Research Square on 22 February 2022 by Gutkind, J. S., Saddawi-Konefka, R., et al.
PubMed
Despite the promise of immune checkpoint inhibition (ICI), therapeutic responses remain limited. This raises the possibility that standard of care treatments delivered in concert may compromise the tumor response. To address this, we employed tobacco-signature HNSCC murine models in which we mapped tumor-draining lymphatics and developed models for regional lymphablation with surgery or radiation. Remarkably, we found that lymphablation eliminates the tumor ICI response, significantly worsening overall survival and repolarizing the tumor- and peripheral- immune compartments. Mechanistically, within tumor-draining lymphatics, we observed an upregulation of cDC1 cells and IFN-I signaling and show that both are necessary for the ICI response and lost with lymphablation. Ultimately, we provide a mechanistic understanding of how standard oncologic therapies targeting regional lymphatics impact the tumor response to immune- oncology therapy in order to define rational, lymphatic-preserving treatment sequences that mobilize systemic antitumor immunity, achieve optimal tumor responses, control regional metastatic disease, and confer durable antitumor immunity.
