Mega-scale single-cell profiling reveals novel biomarkers associated with acute GvHD after allogeneic hematopoietic stem cell transplantation

BACKGROUND: Alloreactive T cells mediate graft-versus-leukemia (GvL) reactions and acute graft-versus-host disease (aGvHD) in AML patients following allogeneic hematopoietic stem cell transplantation. METHODS: leukocytes in total by combinatorial barcoding-based mega-scale single-cell RNA sequencing. RESULTS: T helper cells. MDGA1 expression on T cells and NK cells emerged as a novel biomarker potentially associated with aGvHD. Additionally, we observed a significant deficiency of ADGRG1 expression, a marker of alloreactive cytotoxic T cells, by αβ and γδ T cells from relapsed patients. CONCLUSIONS: In conclusion, mega-scale single-cell monitoring of graft and hematopoietic immune cell reconstitution allowed us to demonstrate that MDGA1 and ADGRG1 may function as complementary biomarkers expressed by distinct circulating T cells that are associated with divergent outcomes in AML patients, enabling precise risk stratification of alloHSCT outcomes and presenting potential therapeutic targets.