AUTHOR=Li Shuang , Zou Dawei , Chen Wenhao , Cheng Yating , Britz Gavin W. , Weng Yi-Lan , Liu Zhaoqian TITLE=Ablation of BATF Alleviates Transplant Rejection via Abrogating the Effector Differentiation and Memory Responses of CD8+ T Cells JOURNAL=Frontiers in Immunology VOLUME=13 YEAR=2022 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.882721 DOI=10.3389/fimmu.2022.882721 ISSN=1664-3224 ABSTRACT=

Allogeneic CD8+ T cells are prominently involved in allograft rejection, but how their effector differentiation and function are regulated at a transcriptional level is not fully understood. Herein, we identified the basic leucine zipper ATF-like transcription factor (BATF) as a key transcription factor that drives the effector program of allogeneic CD8+ T cells. We found that BATF is highly expressed in graft-infiltrating CD8+ T cells, and its ablation in CD8+ T cells significantly prolonged skin allograft survival in a fully MHC-mismatched transplantation model. To investigate how BATF dictates allogeneic CD8+ T cell response, BATF–/– and wild-type (WT) CD8+ T cells were mixed in a 1:1 ratio and adoptively transferred into B6.Rag1–/– mice 1 day prior to skin transplantation. Compared with WT CD8+ T cells at the peak of rejection response, BATF–/– CD8+ T cells displayed a dysfunctional phenotype, evident by their failure to differentiate into CD127–KLRG1+ terminal effectors, impaired proliferative capacity and production of pro-inflammatory cytokines/cytotoxic molecules, and diminished capacity to infiltrate allografts. In association with the failure of effector differentiation, BATF–/– CD8+ T cells largely retained TCF1 expression and expressed significantly low levels of T-bet, TOX, and Ki67. At the memory phase, BATF-deficient CD8+ T cells displayed impaired effector differentiation upon allogeneic antigen re-stimulation. Therefore, BATF is a critical transcriptional determinant that governs the terminal differentiation and memory responses of allogeneic CD8+ T cells in the transplantation setting. Targeting BATF in CD8+ T cells may be an attractive therapeutic approach to promote transplant acceptance.