The role of autologous helper and suppressor T cells in the regulation of human granulopoiesis

Helper and suppressor T cells play a physiological role in immunoregulation and possibly in other biological systems. Previous studies have suggested that unfractionated T cells influence human blood cell formation in vitro. Subpopulations of such cells (TM and TG cells) were prepared by immune ox erythrocyte rosetting techniques. Co-cultures were established in semi-solid agar with autologous null lymphocytes as a source of granulocyte-macrophage progenitor cells (CFU-GM). TM(helper) cells produced an increase and TG (suppressor) cells a decrease in the expression of CFU-GM as reflected in the number of GM colonies generated by comparison with cultures of null lymphocytes alone. These data point to a contribution from T lymphocyte subpopulations to the physiological regulation of human granulopoiesis.