Men Show Significantly Higher T Lymphocyte Mediated Immune Responses Against H-Y Than Multiparous Women: Results From A Cross-Sectional Analysis In 114 Volunteer Blood Donors And Implications For Immunotherapy

Background: Immune responses against Y-chromosomal encoded epitopes are well known as a driving force for both strong graft-versus-host (GvH) and graft-versus-leukemia (GvL) effects in female-into-male allogeneic hematopoietic stem cell transplantations (HSCT). Female donors with a history of pregnancies with male infants are likely to carry T lymphocyte based immune responses against minor histocompatibility antigens derived from the Y chromosome (H-Y antigens). A feto-maternal cell transfer and consecutive immunization of the mother forms the likely basis of this phenomenon. Interestingly, male individuals may carry T lymphocyte based immune responses against H-Y as well. So far, little is known about their frequency, their origin and their functionality particularly in light of allogeneic immunotherapy. Therefore, we screened a group of volunteer blood donors including men and women for H-Y responses. This group has been previously reported for immune responses against tumor-associated antigens (Lutz M et al, ASH 2012).