Isoproterenol Infusion Enhances Composition and Function of G-CSF Mobilized Allogeneic Peripheral Blood Hematopoietic Cell Grafts.

Graft-versus-host disease (GvHD) and relapse remain critical challenges in allogeneic hematopoietic cell transplantation (alloHCT). Graft composition is pivotal, with naïve T cells increasing GvHD risk and NK cells improving graft-versus-leukemia (GvL) effects. Acute beta-adrenergic receptor activation mobilizes effector lymphocytes, favorably altering circulating immune cell composition. This study investigated whether infusing the non-selective beta-agonist isoproterenol (ISO) after granulocyte colony-stimulating factor (G-CSF) mobilization enhances peripheral blood hematopoietic cell (PBHC) graft composition and outcomes. Blood samples were collected from 10 healthy volunteers (age 27-41 yrs) after five days of G-CSF hematopoietic cell mobilization, before and after infusion with Isoproteranol (ISO). Isolated PBMCs underwent single cell RNA sequencing (scRNAseq) and gene expression analysis was performed on 26 identified clusters