Study of RGS1's role in T cells from AML patients after allo-HSCT

Disease relapse is a major cause of death in acute myeloid leukemia (AML) patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Resolving characteristics of T cells is critical for predicting clinical responses and developing strategies for immunotherapy. We used single-cell RNA sequencing to resolve the T cells profiles of AML patients who relapsed (RL) or reached remission (CR) after HSCT and for the first time addressed the characteristics of T cells at molecular level under HSCT scenario. Ten canonical T cell sub-types were identified and the dissimilar compositional patterns between RL and CR group were drawn. Of note, we identified a novel CD8 TEFF sub-cluster featured a high level of regulator of G-protein signaling 1 (RGS1) expression enriching in CR group. Higher levels of RGS1 in CD8+ TEFF, CD8+ T and CD3+ T cells were significantly associated with remission after HSCT in AML patients, which could also predict clinical outcomes after allo-HSCT. And the elevation of RGS1 levels in CD8+ T cells increased cytotoxic factor production, possibly by activating the NF-KB signaling pathway. These findings provide valuable insights into T cell characteristics under allo-HSCT and identify RGS1 as a new marker potentially predicting clinical responses for AML after allo-HSCT.