The RMP1-14 monoclonal antibody reacts with mouse PD-1（programmed death-1）also known as CD279。PD-1is a50-55kDa cell surface receptor encoded by the Pdcdcd1gene that belongs to the CD28family of the Ig superfamily.PD-1is transiently expressed on CD4and CD8thymocytes as well as activated T and velymphocytes and myeloid cells.PD-1expression declines after successfuinal in in in in in in of Addigations cd1mRNA is expressed in developing B lymphocytes during the pro-B-cell stage.PD-1’s structure includes a ITIM（immunoreceptor tyrosine-based inhibitory motif）suggesting that PD-1negatively regulates TCR signals。PD-1signals via binding its two ligands，PD-L1and PD-L2both members of the B7family.Upon ligand binding，PD-1signaling inhibits T-cell activation，leading to reduced proliferation，cytokine production，and T-cell death.Additionally，PD-1is know to play proliferation，cytokine production production，T-cel death.Additionaly to plance of opertivance immune disease in mice as PD-1knockout animals show dilated cardiomyopathy，splenomegaly，and loss of peripheral tolerance.Induced PD-L1expression is common in many tumors including squamous cell carcinoma，colon adenocarcinoma，and breast adenocarcinoma.PD-L1overexpression ression ression ress increased resstance of tumoted is.In mouse models of melanoma，tumor growth can be transiently arrested via treatment with antibodies which block the interaction between PD-L1and its receptor PD-1.For these reasons anti-PD-1mediated immunotherapies are currently being explored as cancer treatments.Like the J43antibody the RMP1-14 antibody habody showns of being PD-L1-Ig and mouse PD-L2-Ig to PD-1。
Triplett，T.A.，et al.（2018）。“Reversal of indoleamine2,3-dioxygenase-mediated cancer immune suppression bysystemic kynurenine depletion with a therapeutic enzyme”Nat Biotechnol36（8）：758-764。PubMed
Increased tryptophan（Trp）catabolismin the tumor microenvironment（TME）can mediate immune suppression by upregulation of interferon（IFN）-gamma-inducible indoleamine2,3-dioxygenase（IDO1）and/orectopic expression of the predominantly liver-restricted enzytryptophane3，TDo3）。Whether these effects are due to Trp depletion in the TME or mediated by the accumulation of the IDO1and/or TDO（hereafter referred to as IDO1/TDO）product kynurenine（Kyn）remains controversial。PEGylated kynureninase；hereafter referred to as PEG-KYNase）that degrades Kyninto 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 effect when combined with approved checkpoint inhibitors or with a cancer vaccine for the treatment of large B16-F10melanoma，4T1breast carcinoma or CT26colon carcinom a tumors.PEG-KYNase mediated prolonged deed of Kly in in the dulse in in in in in in effects of IDO 1/TDO upregulation in the TME。
in vivoPD-1/PD-L信号
Grasselly，C.，et al.（2018）。“The Antitumor Activity of Combinations of Cytotoxic Chemotherapy and Immune Checkpoint Inhibitors Is Model-Dependent”Front Immunol9:2100。PubMed
In spite of impressive response rates in multiple cancer types，immune checkpoint inhibitors（ICIs）are active in only a minority of patients。Alternative strategies currently aim to combine immunotherapies with conventional agents such ascytotoxic chemotherapies.Here，we performed a study of PD-1or PDL-1blockade in combination with reference chemotherapies in four fully immunocompetent mouse models of cancer.We analyzed both thein vivoantitumor response，and the tumor immune infiltrate4days after the first treatment。in vivotumor growth experiments revealed variable responsiveness to ICIs between models.We observed enhanced antitumor effects of the combination of immunotherapy with chemotherapy in the MC 38colon and MB 49bladder models，a lack of response in the 4T1breast model，and an inhibition of ICIs activity in the MBT-2blalyflalyflytow.sof tumor samples showed significant differences in all models between untreated and treated mice.At baseline，all the tumor models studied were predominantly infiltrated with cells harboring an immunosuppressive phenotype.Early alterations of the tumor immune infiltrate after treatment wend ound of of of wend ound of wend outable.平衡，平衡between effector cells and immunosuppressive cells in the tumor microenvironment could be altered with some treatment combinations，but this effect was not always correlated with an impact onin vivotumor growth.These results show that the combination of cytotoxic chemotherapy with ICIs may result in enhanced，similar or reduced antitumor activity，in a model-and regimen-dependent fashion.The present investigations should help to select appropriate combination regimens for Is。
in vivoPD-1/PD-L信号
Moynihan，K.D.，et al.（2016）。“Eradication of large established tumors in mice by combination immunotherapy that engages innate and adaptive immune responses”Nat Med.doi:10.1038/nm.4200。PubMed
PDCD1；also known as PD-1）elicits durable tumor regression in metastatic cancer，but these dramatic responses are confined to a minority of patients.This suboptimal outcome is probably due in part to the complex network of immunosuppressive pathways present in advanced tumors，wch hich unlikely to sintive by gnaling checkpoint.Here we describe a combination immunotherapy that recruits a variety of innate and adaptive immune cells to eliminate large tumor burdens in syngeneic tumor models and agenetical engineered mouse of melanoma；toour knowledge tumors of this size have not previously becuments immunity.Maximalantitumor efficacy required four components:atumor-antigen-targeting antibody，arecombinant interleukin-2with an extended half-life，anti-PD-1and a powerful T cell vaccine.Depletion experiments revealed that CD8+T cells，cross-presenting denitic cells and severname required for tumor regression.Effectivetreatment induced infiltration of immune cells and production of inflammatory cytokines in the tumor，enhanced antibody-mediated tumor antigen uptake and promoted antigen spreading.These results demonstrate the capacity of anelicited endogenous immune responsse to destroy large，established turesticent of combination immunotherapies that are capable of curing a majority of tumors in experimental settings typically viewed as intractable。
in vivoPD-1/PD-L信号
Ngiow，S.F.，et al.（2015）。“A Threshold Level of Intratumor CD8+T-cell PD1 Expression Dictates Therapeutic Response to Anti-PD1”Cancer Res75（18）：3800-3811。PubMed
Despite successes，thus far，a significant proportion of the patients treated with anti-PD1antibodies have failed to respond.We use mouse tumor models of anti-PD1 sensitivity and resistance and flow cytometry to assess tumor-infiltrating immune cells immediately after therapy.Wemonstress of 1（PD1（lo）），myeloid，and T-cell PDL1（PDL1（hi））in the tumor microenvironment inversely correlate and dictate the efficicacy of anti-PD1mAb and function of intratumor CD8（+）T cells。In sensitive tumors，we reveal a threshold for PD1downregulation on tumor-infiltrating CD8（+）T cells below which the release of adaptive immune resistance is achieved。In contrast，PD1（hi）T cells in resistant tumors fail to be rescued by anti-PD1therapy and remain dysfunctional unless intratumor PDL1（lo）immune cells are targeted。Intratumor Tregs are partly responsible for the development of anti-PD1-resistant tumors and PD1（hi）CD8（+）T cells。Our analyses provide a framework to interrogate intratumor CD8（+）T-cell PD1and immune PDL1levels and response in human cancer。cancer Res；75（18）；3800-11。（c）2015AACR。
in vivoPD-1/PD-L信号
Evans，E.E.，et al.（2015）。“Antibody Blockade of Semaphorin4D Promotes Immune Infiltration into Tumor and Enhances Response to Other Immunomodulatory Therapies”Cancer Immunol Res3（6）：689-701。PubMed
Semaphorin4D（SEMA4D，CD100）and its receptor plexin-B1（PLXNB1）are broadly expressed in murine and human tumors，and their expression has been shown to correlate with invasive disease in several human tumors.SEMA 4D normally functions to regulate the motility and differentation of multiple cell types，including those of the immune，vascular，and nervous systems.in the setting of cancer，SEMA 4D-PLXNB1interactions have bertedlization and transactivation of ERBB2，but effects on immune-cell trafficking in the tumor microenvironment（TME）have not been investigated。We describe a novel immunomodulatory function of SEMA4D，whereby strong expression of SEMA4D at the invasive margins of actively growing tumors influences the infiltration and distribution of leukocytes in the TME.Antibody neutralization of SEMA4D disrupts this gradient of expression，enhances recruitment of moytes of在，在to the tumor，and shifts the balance of cells and cytokines toward a proinflammatory and antitumor milieu within the TME.This orchestrated change in the tumor architecture was associated with durable tumor rejection in murine Colon26and ERBB2（+）mammary carcinoma models。The immunomodulatory activity of anti-SEMA4D antibody can be enhanced by combination with other immunotherapies，including immune checkpoint inhibition and chemotherapy.Strikingly，the combination of anti-SEMA4D antibody with antibody to CTLA-4acts synergistically to promote complete tur rejectand survivition of ntsnovel mechanism and therapeutic strategy to promote functional immune infiltration into the TME and inhibit tumor progression。
in vivoPD-1/PD-L信号
Zelenay，S.，et al.（2015）。“Cyclooxygenase-Dpendent Tumor Growth through Evasion of Immunity”Cell162（6）：1257-1270。PubMed
The mechanisms by which melanoma and other cancer cells evade anti-tumor immunity remain incompletely understood.Here，we show that the growth of tumors formeed by mutant Braf（V600E）mouse melanomcells inanimmunocompetent host requires their production of prostaglandin E2，which suppresses immunity and fuels tumor-promoting inflammation.Genetic ablation of cyclooxygenases（COX）or prostaglandin E synthases in Braf（V600E）mouse melanoma cells，as well as in Nras（G12D）melanoma or in breast or colorectal cancer cells，renders themsusceptible to immune control and provokes a shift in the tumor inflammatory profile toward classic anti-cancer immune pathways.This mouse COX-dependent inflammatory signature is remarkably conserved in human cutaneous melanoma biopsies，arguing for COX activity as driver of immune suppressions incress incess-pressions ta demonstrate that inhibition of COX synergizes with anti-PD-1blockade in ininducing eradication of tumors，implying that COX inhibitors could be useful adjuvants forimmune-based therapies in cancer patients。
in vivoPD-1/PD-L信号
Zander，R.A.，et al.（2015）。“PD-1 Co-inhibitory and OX40 Co-stimulatory Crosstalk Regulates Helper T Cell Differentiation and Anti-Plasmodium Humoral Immunity”Cell Host Microbe17（5）：628-641。PubMed
The differentiation and protective capacity of Plasmodium-specific T cells are regulated by both positive and negative signals during malaria，but the molecular and cellular details remain poorly defined.Here we show that malaria patients and Plasmodium-infected rodents exhibit atypical expressory of 40 ON CD4T cells and that therapeutic enhancement of OX40signaling enhances helper CD4T cell activity，humoral immunity，and parasite clearance in rodents.However，these beneficial effects of OX40signaling are abrogated following coordinate blockade of PD-1co-inhibitory pathways，wch are sougurigated and已安装的零件emia.Co-administration of biologics blocking PD-1 and promoting OX40signaling induces excessive interferon-gamma that directly limits helper T cell-mediated support of humoral immunity and decreases parasite control.Our results show that targeting OX40can enhance Plasmodium control and hibit to to to to to to to bebit and co-stimulatory pathways in pathogen-specific CD4T cells can impact pathogen clearance。
in vivoPD-1/PD-L信号
Twyman-Saint Victor，C.，et al.（2015）。“Radiation and dual checkpoint blockade activate non-redundant immune mechanisms in cancer”Nature520（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 patientas metanathLA4antibody（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-L1on melanom cells and associated with T-cell exharduse actiming.noma and other cancer types requires radiation，anti-CTLA4andanti-PD-L1/PD-1.Anti-CTLA4predominantly inhibits T-regulatory cells（Treg cells），thereby increasing the CD8T-cell to Treg（CD8/Treg）ratio。Radiation enhances the diversity of the T-cell receptor（TCR）repertoire of intratumoral T cells。Together，anti-CTLA4promotes expansion of T cells，while radiation shapes the TCR repertoire of the expanded peripheral clones.Addition of PD-L1blockade reverses T-cell exhaustion to mitigate in the CD8/Treg ratio and further encourages oligoclonal T-cell expansion。钢轨，钢轨melanoma showing high PD-L1did not respond to radiation plus anti-CTLA4，demonstrated persistent T-cell exhaustion，and rapidly progressed.Thus，PD-L1on melanoma cells allows tumours to escape anti-CTLA4-based therapy，and the combination of radiation，anti-CTLA4andi-Pdrothl protes ugh distinct mechanism。
in vivoPD-1/PD-L信号
Vanpouille-Boox，C.，et al.（2015）。“TGFbeta Is a Master Regulator of Radiation Therapy-Iduced Antitumor Immunity”Cancer Res75（11）：2232-2242。PubMed
T cells directed to endogenous tumor antigens are powerful mediators of tumor regression.Recent immunotherapy advances have identified effective interventions to unleash tumor-specific T-cell activity in patients who naturally develop them.Eliciting T-cell responses to a patients’invital natual diturally develop them.e.Radiation therapy can induce immune responses to model antigens expressed by tumors，but it remains unclear whether it can effectively prime T cells specific for endogenous antigens expressed by poorly immunogenic tumors.We hypothesized that TGFbeta activity is a major obstacle hindering the ability of radiato national re，we show that antibody-mediated TGFbeta neutralization during radiation therapy effectively generates CD8（+）T-cell responses to multiple endogenous tumor antigens in poorly immunogenic mouse carcinomas。Generated T cells were effective at causing regression of irradiated tumors and nonirradiated lung metases or synchronous tumors（abscopal effect）。Gene signatures associated with IFNgamma and immune-mediated rejection were detected in tumors treated with radiation therapy and TGFbeta blockade in combination but as single agents.Upregulation of programmed death（PD），resulting in rapid recurrence.Addition of anti-PD-1antibodies extended survival achieved with radiation and TGFbeta blockade.Thus，TGFbeta is afundamental regulator of radiation therapy’s ability to generate an in situ tumor vaccine.The combination of local radiation thery with TGbetu vaccine of inout novalivel zed strategyfor vaccinating patients against their tumors。
in vivoPD-1/PD-L信号
Mittal，D.，et al.（2014）。“Antimetatic effects of blocking PD-1 and the adenosine A2A receptor”Cancer Res74（14）：3652-3658。PubMed
Adenosine targeting is an attractive new approach to cancer treatment，but no clinical study has yet examined adenosine inhibition in oncology despite the safe clinical profile of adenosine A2A receptor inhibitors（A2ARi）in Parkinson disease。Metastasis is the main cause of cancer-related deaths worldwide，and therefore we have studied experimental and spontaneous mouse models of melanoma and breast cancer metastasis to demonstrate the efficicacy and mechanismofa combination of A2ARi in combination with anti-PD-1monoclonaal boantidy（mAb）。This combination significantly reduces metastatic burden and prolongs the life of mice compared wither monotherapy alone.Importantly，the combination was only effective when the tumor expressed high levels of CD73，suggesting a tumor biomarker that a minimum could be used to stratify patiments that Thenatimenism of the combination therapy was critically dependent on NK cells and IFNgamma，and to a lesser extent，CD8（+）T cells and the effector molecule，perforin.Overall，these results provide a strong rationale to use A2ARi with anti-PD-1mAb for the treatment of minimal residual and metatic disease。
in vivoPD-1/PD-L信号
cGray，A.J.，et al.（2014）。“Immunotherapy-induced CD8+T cells instigate immune suppression in the tumor”Mol Ther22（1）：206-218。PubMed
Despite clear evidence of immunogenicity，cancer vaccines only provide a modest clinical benefit.To evaluate the mechanisms that limit tumor regression following vaccination，we have investigated the weak efficacy of a highly immunogenic experimental vaccine using a murine melanommodel.Wescovered the weats the immuneattack instigated by tumor-specific CD8+T cells in the first few days following vaccination，resulting in the upregulation of a complex set of biological networks，including multiple immunosuppressive processes.This rapid adaptation acts to prevent sustained local immune attack，despite continued intumboration specific T cells.Combing vaccination with adoptive transfer of tumor-specific T cells produced complete regression of the treated tumors but did not prevent the adaptive immunosuppression.Infact，the adaptive immunosuppressive pathways were more highly induced in regressing tumors，commenssurate with the hanced of inactof tumor infiltrating T-cell functionality revealed that the adaptive immunosuppression leads to a progressive loss in T-cell function，even in in tumors that are regressing.These novel observations that T cells produced by therapeutic intervention can instigapid adaptive immunosuppressive response response within the tumortfor clinical implementation of immunotherapies。
in vivoPD-1/PD-L信号
John，L.B.，et al.（2013）。“Anti-PD-1antibody therapy potently enhances the eradication of established tumors by gene-modified T cells”Clin Cancer Res19（20）：5636-5646。PubMed
PURPOSE:To determine the antitumor efficicacy and toxicity of anovel combination approach involving adoptive T-cell immunotherapy using chimeric antigen receptor（CAR）T cells with an immunomodulatory reagent for blocking immunosuppression。EXPERIMENTAL DESIGN:We examined whether administration of a PD-1blocking antibody could increase the therapeutic activity of CAR T cells against two different Her-2（+）tumors。Theuse of a self-antigen mouse model enabled investigation into the efficacy，mechanism，and toxicity of this combination approach.RESULTS:In this study，we first showed a significant increase in the level of PD-1expressed on transduced anti-Her-2CD8（+T cells folllowing increase in in in in in in in in in in in in difice）tumor cells and that markers of activation and proliferation were increased in anti-Her-2T cells in the presence of anti-PD-1antibody。In adoptive transfer studies in Her-2transgenic recipient mice，we showed asignificant improvement in growth inhibition of two different Her-2（+）tumors treated with anti-Her-2T cells in combination with anti-PD-1antibody。Thetherapeutic effects observed correlated with increased function of anti-Her-2T cells following PD-1blockade.Strikingly，asignificant decrease in the percentage of Gr1（+）CD11b（+）myeloid-derived suppressor cells（MDSC）was observed in the tumor microenvironment of treation of nath。Importantly，increased antitumor effects were not associated with any autoimmune pathology in normal tissue expressing Her-2antigen.CONCLUSION:This study shows that specifically blocking PD-1immunosuppression can potently enhance CAR T-cell therapy that has significant plications for potealtimpouthery of is approacin patients with cancer。
in vivoPD-1/PD-L信号
Holmgaard，R.B.，et al.（2013）。“Indoleamine2,3-dioxygenase is a critical resistance mechanismin antitumor T cell immunotherapy targeting CTLA-4”J Exp Med210（7）：1389-1402。PubMed
ThecytotoxicTlymphocyte antigen-4（CTLA-4）-blocking antibody ipilimumab results in durable responses in metatic melanoma，though therapeutic benefit has been limited to a fraction of patients.This calls for identification of resistance mechanisms and development of combinatorial strategies.Here，we examine the inhibitory role of indoleamine2,3-dioxygenase（IDO）on the antitumor efficicacy of CTLA-4blockade。In IDO knockout mice treated with anti-CTLA-4antibody，we demonstrate a striking delay in B16melanoma tumor growth and increased overall survival when compared with with wild-type mice.This was also observed with antibodies targeting PD-1-PD-L1 and GITR.To highlight the aputing，rewends of show that CTLA-4 blockade stronglysynergizes with IDO inhibitors to mediate rejection of both IDO-expressing and nonexpressing poorly immunogenic tumors，emphasizing the importance of the inhibitory role of both tumor-and host-derived IDO.This effect was T cell dependent，leading to enhanced infiltration of tumor-specifice ffect effector cet in in or to-regulatory T cell ratios in the tumors。Overall，these data demonstrate the immunosuppressive role of IDO in the context of immunotherapies targeting immune checkpoints and provide a strong incentive to clinically explore combination therapies using IDO inhibitors irrespective of IDO expression by the tumor cells。
in vivoPD-1/PD-L信号
van der Werf，N.，et al.（2013）。“Th2cell-intrinsic hypo-responsiveness determines susceptibility to helminth infection”PLoS Pathog9（3）：e1003215。PubMed
The suppression of protective Type2immunity is a principal factor driving the chronicity of helminth infections，and has been attributed to a range of Th2cell-extrinsic immune-regulators.However，the intrinsic fate of parasite-specific Th2cells within a chronic immune down-regulatory environment，the ges mayhave on host resistance is unknown.We used IL-4gfp reporter mice to demonstrate that during chronic helminfection with the filarial nematode Litomosoides sigmodontis，CD4（+）Th2cells are conditioned towards an intrinsically hypo-responsive phenotype，characterised by aloss of functional ability to proliferate and produce the cytokines IL-4，IL-5 and IL-2.Th2cell hypo-responsiveness was akey element determining susceptibility to L.sigmodontis infection，and could be reversedin vivoby blockade of PD-1resulting in long-term recovery of Th2cell functional quality and enhanced resistance.Contrasting with T cell dysfunction in Type1settings，the control of Th2cell hypo-responsiveness by PD-1was mediated through PD-L2，and not PD-L1.Thus，intrinc channic Thalines tionally hypo-responsive phenotype play akey role in determining susceptibility to filarial infection，and the therapeutic manipulation of Th2cell-intrinsic quality provides a potential avenue for promoting resistance to helminths。
in vivoPD-1/PD-L信号
Curran，M.A.，et al.（2010）。“PD-1and CTLA-4combination blockade expands infiltrating T cells and reduces regulatory T and myeloid cells within B16melanoma tumors”Proc Natl Acad Sci U S A107（9）：4275-4280。PubMed
Vaccination with irradiated B16melanoma cells expressing either GM-CSF（Gvax）or Flt3-ligand（Fvax）combined with antibody blockade of the negative T-cell costimulatory rececytotoxic T-lymphocyte antigen-4（CTLA-4）promotes rejection of preimplanted turs。Despite CTLA-4blockade，T-cell proliferation and cytokine production can be inhibited by the interaction of programmed death-1（PD-1）with its ligands PD-L1and PD-L2or by the interaction of PD-L1 with B7-1。Here，we show that the combination of CTLA-4and PD-1blockade is more than twice as effective as either alone in promoting the rejection of B16melanomas in conjunction with Fvax.Adding alphaPD-L1 to this regimen results in rejection of 65%of preimplanted tumors vs.10%with CTLA-4ckadalcombe and blockade increaseseffector T-cell（Teff）infiltration，resulting in highly advantageous Teff-to-regulatory T-cell ratios with the tumor.The fraction of tumor-infiltrating Teffs expressing CTLA-4and PD-1 increases，reflecting the proliferation and accumulation of cells that would otherwise be anergized.Combination blockade alsosynergisticallically of cells竖向受压器中心梁within B16melanomas.IFN-gamma production increases in both the tumor and vaccine draining lymph nodes，as does the frequency of IFN-gamma/TNF-alpha double-producing CD8（+）T cells within the tumor。These results suggest that combination blockade of the PD-1/PD-L1-and CTLA-4-negative costimulatory pathways allows tumor-specific T cells that would otherwise be inactivated to continue to expand and carry out effector functions，thereby shifting the tumor microenvironment from supportamative。
