RESUMO
The efficacy of T cell-based immunotherapies is limited by immunosuppressive pressures in the tumor microenvironment. Here we show a predominant role for the interaction between BTLA on effector T cells and HVEM (TNFRSF14) on immunosuppressive tumor microenvironment cells, namely regulatory T cells. High BTLA expression in chimeric antigen receptor (CAR) T cells correlated with poor clinical response to treatment. Therefore, we deleted BTLA in CAR T cells and show improved tumor control and persistence in models of lymphoma and solid malignancies. Mechanistically, BTLA inhibits CAR T cells via recruitment of tyrosine phosphatases SHP-1 and SHP-2, upon trans engagement with HVEM. BTLA knockout thus promotes CAR signaling and subsequently enhances effector function. Overall, these data indicate that the BTLA-HVEM axis is a crucial immune checkpoint in CAR T cell immunotherapy and warrants the use of strategies to overcome this barrier.
Assuntos
Imunoterapia Adotiva , Receptores de Antígenos Quiméricos , Receptores Imunológicos , Membro 14 de Receptores do Fator de Necrose Tumoral , Microambiente Tumoral , Animais , Humanos , Imunoterapia Adotiva/métodos , Membro 14 de Receptores do Fator de Necrose Tumoral/metabolismo , Membro 14 de Receptores do Fator de Necrose Tumoral/imunologia , Membro 14 de Receptores do Fator de Necrose Tumoral/genética , Camundongos , Microambiente Tumoral/imunologia , Receptores de Antígenos Quiméricos/imunologia , Receptores de Antígenos Quiméricos/metabolismo , Receptores de Antígenos Quiméricos/genética , Receptores Imunológicos/metabolismo , Receptores Imunológicos/genética , Linfócitos T Reguladores/imunologia , Transdução de Sinais , Linhagem Celular Tumoral , Neoplasias/imunologia , Neoplasias/terapia , Camundongos KnockoutRESUMO
Cell surface molecules transiently upregulated on activated T cells can play a counter-regulatory role by inhibiting T cell function. Deletion or blockade of such immune checkpoint receptors has been investigated to improve the function of engineered immune effector cells. CD38 is upregulated on activated T cells, and although there have been studies showing that CD38 can play an inhibitory role in T cells, how it does so has not fully been elucidated. In comparison with molecules such as PD1, CTLA4, LAG3, and TIM3, we found that CD38 displays more sustained and intense expression following acute activation. After deleting CD38 from human chimeric antigen receptor (CAR) T cells, we showed relative resistance to exhaustion in vitro and improved anti-tumor function in vivo. CD38 is a multifunctional ectoenzyme with hydrolase and cyclase activities. Reintroduction of CD38 mutants into T cells lacking CD38 provided further evidence supporting the understanding that CD38 plays a crucial role in producing the immunosuppressive metabolite adenosine and utilizing nicotinamide adenine dinucleotide (NAD) in human T cells. Taken together, these results highlight a role for CD38 as an immunometabolic checkpoint in T cells and lead us to propose CD38 deletion as an additional avenue for boosting CAR T cell function.