Colonizing Capacity of Lymphoid Cells Injected into Syngeneic Hosts

Abstract

Suspensions of lymphoid cells from different tissues (spleen, lymph nodes, thymus and bone marrow) injected neonatally into syngeneic hosts yield low proportions of dividing donor cells in the spleen, thymus and bone marrow. In contrast, the ability of various inocula to colonize the lymph nodes differs greately and can in general be correlated with the content of circulating lymphocytes within the inoculum. The higher the proportion of circulating lymphocytes in the inoculum the higher the ability of that inoculum to colonize the host lymph nodes (1). However, the capacity of spleen inoculum to colonize the lymph nodes can be increased several fold if the neonatal recipient is thymectomized prior to cell injection (2). This phenomenon is shown to be specific, since the ability of the inoculum to colonize the other lymphoid organs remains unlatered (2,3). Thus, it was suggested that thymus, through unknown mechanism ensures selective entry of circulating lymphocytes into the lymph nodes.