Effect of splenectomy on the induction of high degrees of tolerance to skin allografts in rats

The effect of splenectomy on the induction of neonatal tolerance to histocompatibility antigens was studied. Newborn BN ($\text{Ag-B}{}^3\text{Ag-B}{}^3$) rats were splenectomized or sham splenectomized prior to transfer of a tolerance-inducing inoculum of Lewis/BN ($\text{Ag-B}{}^1\text{Ag-B}{}^3$) bone marrow cells. Twenty-two percent of the splenectomized animals were found to be highly tolerant of subsequent Lewis skin allografts, compared to 53.8% of the shamsplenectomized group. In addition seven of eight incompletely splenectomized animals were found to be highly tolerant. The relevance of these data to currently postulated mechanisms of classical neonatal tolerance induction is discussed.