Clonal Deletion of Donor-Reactive T Cell Subsets in Prenatal Allogeneic Chimeras is Preserved During Potent Viral Infection

Abstract

Long-term engraftment following in utero hematopoietic stem cell transplantation (IUHCT) requires the development of T cell tolerance through the deletion of alloreactive T cell clones and anergy in the remaining non-deleted clones. In response to viral illness, however, a dramatic T cell expansion occurs which may include the expansion of anergic alloreactive T cells. Expansion of these subsets could result in an abrupt rejection of previously engrafted donor cells, permitting devastating relapse of disease in the patient.