Dados do Resumo

Título

Epigenetic Inhibition of CPB/p300 Rejuvenates Exhausted Tumor-Infiltrating Lymphocytes in Clear Cell Renal Carcinoma

Introdução

Clear cell renal cell carcinoma (ccRCC) is highly prevalent and curative treatment for this type of tumor, particularly in advanced stages, remains rare. Adoptive therapies (AT) with chimeric antigen receptor T cells (CAR-T) and tumor-infiltrating lymphocytes (TIL) have emerged as an option for the treatment of solid tumors, including ccRCC, however, the rates of complete response are still considered low. Therefore, alternative strategies that can enhance the antitumor function of TIL in ccRCC may represent an innovative approach, aiming greater efficacy in ccRCC treatment.

Objetivo

Considering that TIL undergo a complex process of cellular differentiation and epigenetic commitment that leads them to terminal exhaustion, we hypothesize that epigenetic inhibition of the CBP/p300 complex could rescue terminally exhausted ccRCC TILs, converting them into a less differentiated phenotype with enhanced antitumor activity.

Métodos

ccRCC tumor fragments were collected and digested in a collagenase IV cocktail (Research Ethics Committee - 3223/22). The cell suspension was then processed using a Cell Sorter (BD FACSAria) to isolate the total population of TIL (CD45+CD3+CD56-). Subsequently, to assess the epigenetic inhibitor targeting CBP/p300 modulatory capacity on TIL effector function, they were stimulated with anti-CD3 and anti-CD28 Dynabeads, as well as rhIL-2 in the presence or absence of the epigenetic inhibitor. After 24 hours of treatment, T cell subpopulations, activation and exhaustion were evaluated using multiparametric flow cytometry (BD FACSymphony).

Resultados

The preliminary results showed that epigenetic inhibition of the CBP/p300 complex induced both CD4 and CD8 T cell populations to a less differentiated (naïve/stem cell-like memory) and more effector phenotype compared to the control. Additionally, there was a dramatic reduction of inhibitory marker expressions, such as PD-1, LAG-3, TIGIT, TIM-3, and CD39 in both populations. Analysis of the frequency of cells expressing 0 to 5 inhibitory markers in the CD4 and CD8 cell populations revealed that inhibition of the CBP/p300 complex reduced the frequency of cells expressing 2, 3, 4, or 5 inhibitory markers and increased the frequency of cells expressing no inhibitory markers compared to the control treatment.

Conclusões

Based on the detailed characterization of TILs in ccRCC, our data show that the epigenetic inhibition of the CBP/p300 complex modulates the phenotype of TILs, changing their status from terminally exhausted cells to less differentiated and more effector-like cells. Therefore, these data suggest that the epigenetic remodeling of TILs could emerge as an innovative strategy for treating ccRCC.

Financiador do resumo

FAPESP, CAPES, CNPq

Palavras Chave

immunotherapy; epigenetics; Tumor Infiltrating Lymphocytes (TIL)