RESUMEN
Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of T-cell receptor signaling and as such is an attractive target for cancer immunotherapy. Although the role of the HPK1 kinase domain (KD) has been extensively characterized, the function of its citron homology domain (CHD) remains elusive. Through a combination of structural, biochemical, and mechanistic studies, we characterize the structure-function of CHD in relationship to KD. Crystallography and hydrogen-deuterium exchange mass spectrometry reveal that CHD adopts a seven-bladed ß-propellor fold that binds to KD. Mutagenesis associated with binding and functional studies show a direct correlation between domain-domain interaction and negative regulation of kinase activity. We further demonstrate that the CHD provides stability to HPK1 protein in cells as well as contributes to the docking of its substrate SLP76. Altogether, this study highlights the importance of the CHD in the direct and indirect regulation of HPK1 function.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Serina-Treonina Quinasas , Fosforilación , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/química , Humanos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/química , Fosfoproteínas/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Unión Proteica , Dominios Proteicos , Cristalografía por Rayos X , Células HEK293RESUMEN
Dual blockade of the PD-1 and TIGIT coinhibitory receptors on T cells shows promising early results in cancer patients. Here, we studied the mechanisms whereby PD-1 and/or TIGIT blockade modulate anti-tumor CD8+ T cells. Although PD-1 and TIGIT are thought to regulate different costimulatory receptors (CD28 and CD226), effectiveness of PD-1 or TIGIT inhibition in preclinical tumor models was reduced in the absence of CD226. CD226 expression associated with clinical benefit in patients with non-small cell lung carcinoma (NSCLC) treated with anti-PD-L1 antibody atezolizumab. CD226 and CD28 were co-expressed on NSCLC infiltrating CD8+ T cells poised for expansion. Mechanistically, PD-1 inhibited phosphorylation of both CD226 and CD28 via its ITIM-containing intracellular domain (ICD); TIGIT's ICD was dispensable, with TIGIT restricting CD226 co-stimulation by blocking interaction with their common ligand PVR (CD155). Thus, full restoration of CD226 signaling, and optimal anti-tumor CD8+ T cell responses, requires blockade of TIGIT and PD-1, providing a mechanistic rationale for combinatorial targeting in the clinic.
Asunto(s)
Linfocitos T CD8-positivos , Neoplasias , Antígenos de Diferenciación de Linfocitos T/metabolismo , Antígenos CD28/metabolismo , Humanos , Neoplasias/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Receptores Inmunológicos/metabolismoRESUMEN
Inhibitors of the programmed cell death-1 (PD-1/PD-L1) signaling axis are approved to treat non-small cell lung cancer (NSCLC) patients, based on their significant overall survival (OS) benefit. Using transcriptomic analysis of 891 NSCLC tumors from patients treated with either the PD-L1 inhibitor atezolizumab or chemotherapy from two large randomized clinical trials, we find a significant B cell association with extended OS with PD-L1 blockade, independent of CD8+ T cell signals. We then derive gene signatures corresponding to the dominant B cell subsets present in NSCLC from single-cell RNA sequencing (RNA-seq) data. Importantly, we find increased plasma cell signatures to be predictive of OS in patients treated with atezolizumab, but not chemotherapy. B and plasma cells are also associated with the presence of tertiary lymphoid structures and organized lymphoid aggregates. Our results suggest an important contribution of B and plasma cells to the efficacy of PD-L1 blockade in NSCLC.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Antígeno B7-H1/genética , Antígeno B7-H1/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/patología , Humanos , Inhibidores de Puntos de Control Inmunológico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Células Plasmáticas/patologíaRESUMEN
BACKGROUND: CD8+ tissue-resident memory T (TRM) cells, marked by CD103 (ITGAE) expression, are thought to actively suppress cancer progression, leading to the hypothesis that their presence in tumors may predict response to immunotherapy. METHODS: Here, we test this by combining high-dimensional single-cell modalities with bulk tumor transcriptomics from 1868 patients enrolled in lung and bladder cancer clinical trials of atezolizumab (anti-programmed cell death ligand 1 (PD-L1)). RESULTS: ITGAE was identified as the most significantly upregulated gene in inflamed tumors. Tumor CD103+ CD8+ TRM cells exhibited a complex phenotype defined by the expression of checkpoint regulators, cytotoxic proteins, and increased clonal expansion. CONCLUSIONS: Our analyses indeed demonstrate that the presence of CD103+ CD8+ TRM cells, quantified by tracking intratumoral CD103 expression, can predict treatment outcome, suggesting that patients who respond to PD-1/PD-L1 blockade are those who exhibit an ongoing antitumor T-cell response.
Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Antígenos CD/genética , Antígeno B7-H1/antagonistas & inhibidores , Biomarcadores de Tumor/genética , Linfocitos T CD8-positivos/inmunología , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Cadenas alfa de Integrinas/genética , Neoplasias Pulmonares/tratamiento farmacológico , Linfocitos Infiltrantes de Tumor/inmunología , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados/efectos adversos , Antígeno B7-H1/inmunología , Ensayos Clínicos Fase II como Asunto , Ensayos Clínicos Fase III como Asunto , Bases de Datos Genéticas , Perfilación de la Expresión Génica , Humanos , Inhibidores de Puntos de Control Inmunológico/efectos adversos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/inmunología , Fenotipo , Ensayos Clínicos Controlados Aleatorios como Asunto , Factores de Tiempo , Resultado del Tratamiento , Microambiente Tumoral , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/inmunologíaRESUMEN
Despite the resounding clinical success in cancer treatment of antibodies that block the interaction of PD1 with its ligand PDL11, the mechanisms involved remain unknown. A major limitation to understanding the origin and fate of T cells in tumour immunity is the lack of quantitative information on the distribution of individual clonotypes of T cells in patients with cancer. Here, by performing deep single-cell sequencing of RNA and T cell receptors in patients with different types of cancer, we survey the profiles of various populations of T cells and T cell receptors in tumours, normal adjacent tissue, and peripheral blood. We find clear evidence of clonotypic expansion of effector-like T cells not only within the tumour but also in normal adjacent tissue. Patients with gene signatures of such clonotypic expansion respond best to anti-PDL1 therapy. Notably, expanded clonotypes found in the tumour and normal adjacent tissue can also typically be detected in peripheral blood, which suggests a convenient approach to patient identification. Analyses of our data together with several external datasets suggest that intratumoural T cells, especially in responsive patients, are replenished with fresh, non-exhausted replacement cells from sites outside the tumour, suggesting continued activity of the cancer immunity cycle in these patients, the acceleration of which may be associated with clinical response.
Asunto(s)
Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/metabolismo , Neoplasias/patología , Variantes Farmacogenómicas , Receptores de Antígenos de Linfocitos T/genética , Linfocitos T/citología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Antineoplásicos/uso terapéutico , Células Clonales , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/inmunología , Linfocitos T/metabolismo , TranscriptomaRESUMEN
CD96 is a member of the poliovirus receptor (PVR, CD155)-nectin family that includes T cell Ig and ITIM domain (TIGIT) and CD226. While CD96, TIGIT, and CD226 have important roles in regulating NK cell activity, and TIGIT and CD226 have also been shown to regulate T cell responses, it is unclear whether CD96 has inhibitory or stimulatory function in CD8+ T cells. Here, we demonstrate that CD96 has co-stimulatory function on CD8+ T cells. Crosslinking of CD96 on human or mouse CD8+ T cells induced activation, effector cytokine production, and proliferation. CD96 was found to transduce its activating signal through the MEK-ERK pathway. CD96-mediated signaling led to increased frequencies of NUR77- and T-bet-expressing CD8+ T cells and enhanced cytotoxic effector activity, indicating that CD96 can modulate effector T cell differentiation. Antibody blockade of CD96 or genetic ablation of CD96 expression on CD8+ T cells impaired expression of transcription factors and proinflammatory cytokines associated with CD8+ T cell activation in in vivo models. Taken together, CD96 has a co-stimulatory role in CD8+ T cell activation and effector function.
Asunto(s)
Antígenos CD/inmunología , Linfocitos T CD8-positivos/inmunología , Diferenciación Celular/inmunología , Activación de Linfocitos , Sistema de Señalización de MAP Quinasas/inmunología , Modelos Inmunológicos , Animales , Antígenos CD/genética , Diferenciación Celular/genética , Línea Celular Tumoral , Humanos , Sistema de Señalización de MAP Quinasas/genética , Ratones , Ratones NoqueadosRESUMEN
TRIAL REGISTRATION: ClinicalTrials.gov Clinical Trial NCT00594880.