Maturation of Immunological Responsiveness to Transplantation Antigens1

The “homograft reactivity” of isolated spleen cells was measured by the Simonsen spleen and liver assay. Ten million spleen cells from C57BL/6, CBA and A mice, ranging in age from 5 to 30 days, were injected into newborn homologous homozygous or F1 hybrid assay mice. Using different strain variations we have been able to measure the effect of immunological maturity and genetic relationship between host and donor strain on the expression of “homograft reactivity”. The results suggest that neonatal mice from different strains vary in their immunological response to transplantation antigens. This variation in neonatal mice is largely influenced by the genetic relationship between host and donor. The rate of immunological maturation, with respect to transplantation antigens, varies among the different mouse strains. These differences are due to the genetic disparity between host and donor.