Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros











Base de dados
Intervalo de ano de publicação
1.
Nat Rev Drug Discov ; 21(7): 509-528, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-34937915

RESUMO

Cancer immunity, and the potential for cancer immunotherapy, have been topics of scientific discussion and experimentation for over a hundred years. Several successful cancer immunotherapies - such as IL-2 and interferon-α (IFNα) - have appeared over the past 30 years. However, it is only in the past decade that immunotherapy has made a broad impact on patient survival in multiple high-incidence cancer indications. The emergence of immunotherapy as a new pillar of cancer treatment (adding to surgery, radiation, chemotherapy and targeted therapies) is due to the success of immune checkpoint blockade (ICB) drugs, the first of which - ipilimumab - was approved in 2011. ICB drugs block receptors and ligands involved in pathways that attenuate T cell activation - such as cytotoxic T lymphocyte antigen 4 (CTLA4), programmed cell death 1 (PD1) and its ligand, PDL1 - and prevent, or reverse, acquired peripheral tolerance to tumour antigens. In this Review we mark the tenth anniversary of the approval of ipilimumab and discuss the foundational scientific history of ICB, together with the history of the discovery, development and elucidation of the mechanism of action of the first generation of drugs targeting the CTLA4 and PD1 pathways.


Assuntos
Inibidores de Checkpoint Imunológico , Neoplasias , Antígeno CTLA-4 , Humanos , Imunoterapia , Ipilimumab/farmacologia , Ipilimumab/uso terapêutico , Receptor de Morte Celular Programada 1
2.
J Exp Med ; 218(12)2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34709351

RESUMO

HVEM is a TNF (tumor necrosis factor) receptor contributing to a broad range of immune functions involving diverse cell types. It interacts with a TNF ligand, LIGHT, and immunoglobulin (Ig) superfamily members BTLA and CD160. Assessing the functional impact of HVEM binding to specific ligands in different settings has been complicated by the multiple interactions of HVEM and HVEM binding partners. To dissect the molecular basis for multiple functions, we determined crystal structures that reveal the distinct HVEM surfaces that engage LIGHT or BTLA/CD160, including the human HVEM-LIGHT-CD160 ternary complex, with HVEM interacting simultaneously with both binding partners. Based on these structures, we generated mouse HVEM mutants that selectively recognized either the TNF or Ig ligands in vitro. Knockin mice expressing these muteins maintain expression of all the proteins in the HVEM network, yet they demonstrate selective functions for LIGHT in the clearance of bacteria in the intestine and for the Ig ligands in the amelioration of liver inflammation.


Assuntos
Antígenos CD/metabolismo , Receptores Imunológicos/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/química , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo , Animais , Antígenos CD/química , Antígenos CD/genética , Cristalografia por Raios X , Drosophila/citologia , Drosophila/genética , Feminino , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Complexos Multiproteicos/química , Complexos Multiproteicos/metabolismo , Mutação , Receptores Imunológicos/química , Receptores Imunológicos/genética , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/química , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Yersiniose/genética , Yersiniose/patologia
3.
Structure ; 28(11): 1197-1205.e2, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-32795404

RESUMO

Herpes virus entry mediator (HVEM) regulates positive and negative signals for T cell activation through co-signaling pathways. Dysfunction of the HVEM co-signaling network is associated with multiple pathologies related to autoimmunity, infectious disease, and cancer, making the associated molecules biologically and therapeutically attractive targets. HVEM interacts with three ligands from two different superfamilies using two different binding interfaces. The engagement with ligands CD160 and B- and T-lymphocyte attenuator (BTLA), members of immunoglobulin superfamily, is associated with inhibitory signals, whereas inflammatory responses are regulated through the interaction with LIGHT from the TNF superfamily. We computationally redesigned the HVEM recognition interfaces using a residue-specific pharmacophore approach, ProtLID, to achieve switchable-binding specificity. In subsequent cell-based binding assays the new interfaces, designed with only single or double mutations, exhibited selective binding to only one or two out of the three cognate ligands.


Assuntos
Antígenos CD/química , Receptores Imunológicos/química , Membro 14 de Receptores do Fator de Necrose Tumoral/química , Receptores Virais/química , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/química , Antígenos CD/genética , Antígenos CD/metabolismo , Sítios de Ligação , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Expressão Gênica , Células HEK293 , Herpesvirus Humano 1/genética , Herpesvirus Humano 1/metabolismo , Humanos , Cinética , Simulação de Dinâmica Molecular , Mutação , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Engenharia de Proteínas/métodos , Domínios e Motivos de Interação entre Proteínas , Receptores Imunológicos/genética , Receptores Imunológicos/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia Estrutural de Proteína , Linfócitos T/metabolismo , Linfócitos T/virologia , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/genética , Membro 14 da Superfamília de Ligantes de Fatores de Necrose Tumoral/metabolismo
4.
PLoS One ; 15(6): e0233578, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497097

RESUMO

The B7 family represents one of the best-studied subgroups within the Ig superfamily, yet new interactions continue to be discovered. However, this binding promiscuity represents a major challenge for defining the biological contribution of each specific interaction. We developed a strategy for addressing these challenges by combining cell microarray and high-throughput FACS methods to screen for promiscuous binding events, map binding interfaces, and generate functionally selective reagents. Applying this approach to the interactions of mPD-L1 with its receptor mPD-1 and its ligand mB7-1, we identified the binding interface of mB7-1 on mPD-L1 and as a result generated mPD-L1 mutants with binding selectivity for mB7-1 or mPD-1. Next, using a panel of mB7-1 mutants, we mapped the binding sites of mCTLA-4, mCD28 and mPD-L1. Surprisingly, the mPD-L1 binding site mapped to the dimer interface surface of mB7-1, placing it distal from the CTLA-4/CD28 recognition surface. Using two independent approaches, we demonstrated that mPD-L1 and mB7-1 bind in cis, consistent with recent reports from Chaudhri A et al. and Sugiura D et al. We further provide evidence that while CTLA-4 and CD28 do not directly compete with PD-L1 for binding to B7-1, they can disrupt the cis PD-L1:B7-1 complex by reorganizing B7-1 on the cell surface. These observations offer new functional insights into the regulatory mechanisms associated with this group of B7 family proteins and provide new tools to elucidate their function in vitro and in vivo.


Assuntos
Complexo Antígeno-Anticorpo/metabolismo , Antígeno B7-1/metabolismo , Antígeno B7-H1/metabolismo , Proteínas Mutantes/metabolismo , Animais , Antígenos de Superfície/metabolismo , Antígeno B7-1/genética , Antígeno B7-H1/genética , Sítios de Ligação , Antígenos CD28/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Antígeno CTLA-4/metabolismo , Células HEK293 , Humanos , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica , Transfecção
5.
Sci Transl Med ; 11(485)2019 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-30918115

RESUMO

Early clinical results of chimeric antigen receptor (CAR) T cell therapy targeting B cell maturation antigen (BCMA) for multiple myeloma (MM) appear promising, but relapses associated with residual low-to-negative BCMA-expressing MM cells have been reported, necessitating identification of additional targets. The orphan G protein-coupled receptor, class C group 5 member D (GPRC5D), normally expressed only in the hair follicle, was previously identified as expressed by mRNA in marrow aspirates from patients with MM, but confirmation of protein expression remained elusive. Using quantitative immunofluorescence, we determined that GPRC5D protein is expressed on CD138+ MM cells from primary marrow samples with a distribution that was similar to, but independent of, BCMA. Panning a human B cell-derived phage display library identified seven GPRC5D-specific single-chain variable fragments (scFvs). Incorporation of these into multiple CAR formats yielded 42 different constructs, which were screened for antigen-specific and antigen-independent (tonic) signaling using a Nur77-based reporter system. Nur77 reporter screen results were confirmed in vivo using a marrow-tropic MM xenograft in mice. CAR T cells incorporating GPRC5D-targeted scFv clone 109 eradicated MM and enabled long-term survival, including in a BCMA antigen escape model. GPRC5D(109) is specific for GPRC5D and resulted in MM cell line and primary MM cytotoxicity, cytokine release, and in vivo activity comparable to anti-BCMA CAR T cells. Murine and cynomolgus cross-reactive CAR T cells did not cause alopecia or other signs of GPRC5D-mediated toxicity in these species. Thus, GPRC5D(109) CAR T cell therapy shows potential for the treatment of advanced MM irrespective of previous BCMA-targeted therapy.


Assuntos
Imunoterapia Adotiva/métodos , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/terapia , Receptores de Antígenos Quiméricos/metabolismo , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/imunologia , Animais , Especificidade de Anticorpos , Antígeno de Maturação de Linfócitos B/antagonistas & inibidores , Antígeno de Maturação de Linfócitos B/imunologia , Linhagem Celular Tumoral , Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Mieloma Múltiplo/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Acoplados a Proteínas G/genética , Anticorpos de Cadeia Única/uso terapêutico , Pesquisa Translacional Biomédica , Ensaios Antitumorais Modelo de Xenoenxerto
6.
Mol Ther ; 26(6): 1447-1456, 2018 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-29678657

RESUMO

B cell maturation antigen (BCMA) has recently been identified as an important multiple myeloma (MM)-specific target for chimeric antigen receptor (CAR) T cell therapy. In CAR T cell therapy targeting CD19 for lymphoma, host immune anti-murine CAR responses limited the efficacy of repeat dosing and possibly long-term persistence. This clinically relevant concern can be addressed by generating a CAR incorporating a human single-chain variable fragment (scFv). We screened a human B cell-derived scFv phage display library and identified a panel of BCMA-specific clones from which human CARs were engineered. Despite a narrow range of affinity for BCMA, dramatic differences in CAR T cell expansion were observed between unique scFvs in a repeat antigen stimulation assay. These results were confirmed by screening in a MM xenograft model, where only the top preforming CARs from the repeat antigen stimulation assay eradicated disease and prolonged survival. The results of this screening identified a highly effective CAR T cell therapy with properties, including rapid in vivo expansion (>10,000-fold, day 6), eradication of large tumor burden, and durable protection to tumor re-challenge. We generated a bicistronic construct including a second-generation CAR and a truncated-epithelial growth factor receptor marker. CAR T cell vectors stemming from this work are under clinical investigation.


Assuntos
Antígeno de Maturação de Linfócitos B/metabolismo , Imunoterapia Adotiva/métodos , Anticorpos de Cadeia Única/imunologia , Imunidade Adaptativa/fisiologia , Linfócitos T CD4-Positivos/metabolismo , Herpesvirus Humano 4/imunologia , Humanos , Receptores de Antígenos de Linfócitos T/metabolismo
7.
Proc Natl Acad Sci U S A ; 114(21): E4223-E4232, 2017 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-28484017

RESUMO

Rational modulation of the immune response with biologics represents one of the most promising and active areas for the realization of new therapeutic strategies. In particular, the use of function blocking monoclonal antibodies targeting checkpoint inhibitors such as CTLA-4 and PD-1 have proven to be highly effective for the systemic activation of the human immune system to treat a wide range of cancers. Ipilimumab is a fully human antibody targeting CTLA-4 that received FDA approval for the treatment of metastatic melanoma in 2011. Ipilimumab is the first-in-class immunotherapeutic for blockade of CTLA-4 and significantly benefits overall survival of patients with metastatic melanoma. Understanding the chemical and physical determinants recognized by these mAbs provides direct insight into the mechanisms of pathway blockade, the organization of the antigen-antibody complexes at the cell surface, and opportunities to further engineer affinity and selectivity. Here, we report the 3.0 Å resolution X-ray crystal structure of the complex formed by ipilimumab with its human CTLA-4 target. This structure reveals that ipilimumab contacts the front ß-sheet of CTLA-4 and intersects with the CTLA-4:Β7 recognition surface, indicating that direct steric overlap between ipilimumab and the B7 ligands is a major mechanistic contributor to ipilimumab function. The crystallographically observed binding interface was confirmed by a comprehensive cell-based binding assay against a library of CTLA-4 mutants and by direct biochemical approaches. This structure also highlights determinants responsible for the selectivity exhibited by ipilimumab toward CTLA-4 relative to the homologous and functionally related CD28.


Assuntos
Complexo Antígeno-Anticorpo/metabolismo , Antineoplásicos Imunológicos/farmacologia , Sítios de Ligação de Anticorpos/imunologia , Antígeno CTLA-4/antagonistas & inibidores , Ipilimumab/farmacologia , Melanoma/tratamento farmacológico , Fatores Biológicos/farmacologia , Antígeno CTLA-4/imunologia , Linhagem Celular , Cristalografia por Raios X , Células HEK293 , Humanos , Imunoterapia/métodos , Ligação Proteica , Estrutura Terciária de Proteína
8.
Cell Rep ; 9(3): 1089-98, 2014 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-25437562

RESUMO

B7x (B7-H4 or B7S1) is a member of the B7 family that can inhibit T cell function. B7x protein is absent in most normal human tissues and immune cells, but it is overexpressed in human cancers and often correlates with negative clinical outcome. The expression pattern and function of B7x suggest that it may be a potent immunosuppressive pathway in human cancers. Here, we determined the crystal structure of the human B7x immunoglobulin variable (IgV) domain at 1.59 Å resolution and mapped the epitopes recognized by monoclonal antibodies. We developed an in vivo system to screen therapeutic monoclonal antibodies against B7x and found that the clone 1H3 significantly inhibited growth of B7x-expressing tumors in vivo via multiple mechanisms. Furthermore, the surviving mice given 1H3 treatment were resistant to tumor rechallenge. Our data suggest that targeting B7x on tumors is a promising cancer immunotherapy and humanized 1H3 may be efficacious for immunotherapy of human cancers.


Assuntos
Imunoterapia , Neoplasias/imunologia , Neoplasias/terapia , Inibidor 1 da Ativação de Células T com Domínio V-Set/química , Inibidor 1 da Ativação de Células T com Domínio V-Set/imunologia , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais/farmacologia , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Modelos Animais de Doenças , Mapeamento de Epitopos , Epitopos/química , Epitopos/imunologia , Humanos , Terapia de Imunossupressão , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Camundongos Endogâmicos BALB C , Modelos Moleculares , Neoplasias/patologia , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Ressonância de Plasmônio de Superfície , Análise de Sobrevida , Linfócitos T/imunologia , Microambiente Tumoral/efeitos dos fármacos , Inibidor 1 da Ativação de Células T com Domínio V-Set/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA