Diacylglycerol kinase α inactivation is an integral component of the costimulatory pathway that amplifies TCR signals.
Cancer Immunol Immunother
; 67(6): 965-980, 2018 06.
Article
en En
| MEDLINE
| ID: mdl-29572701
ABSTRACT
The arsenal of cancer therapies has evolved to target T lymphocytes and restore their capacity to destroy tumor cells. T cells rely on diacylglycerol (DAG) to carry out their functions. DAG availability and signaling are regulated by the enzymes diacylglycerol kinase (DGK) α and ζ, whose excess function drives T cells into hyporesponsive states. Targeting DGKα is a promising strategy for coping with cancer; its blockade could reinstate T-cell attack on tumors while limiting tumor growth, due to positive DGKα functions in several oncogenic pathways. Here, we made a side-by-side comparison of the effects of commercial pharmacological DGK inhibitors on T-cell responses with those promoted by DGKα and DGKζ genetic deletion or silencing. We show the specificity for DGKα of DGK inhibitors I and II and the structurally similar compound ritanserin. Inhibitor treatment promoted Ras/ERK (extracellular signal-regulated kinase) signaling and AP-1 (Activator protein-1) transcription, facilitated DGKα membrane localization, reduced the requirement for costimulation, and cooperated with enhanced activation following DGKζ silencing/deletion. DGKiII and ritanserin had similar effects on TCR proximal signaling, but ritanserin counteracted long-term T-cell activation, an effect that was potentiated in DGKα-/- cells. In contrast with enhanced activation triggered by pharmacological inhibition, DGKα silencing/genetic deletion led to impaired Lck (lymphocyte-specific protein tyrosine kinase) activation and limited costimulation responses. Our results demonstrate that pharmacological inhibition of DGKα downstream of the TCR provides a gain-of-function effect that amplifies the DAG-dependent signaling cascade, an ability that could be exploited therapeutically to reinvigorate T cells to attack tumors.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Linfocitos T
/
Diacilglicerol Quinasa
/
Inmunoterapia
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Cancer Immunol Immunother
Asunto de la revista:
ALERGIA E IMUNOLOGIA
/
NEOPLASIAS
/
TERAPEUTICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
España