Quantitative analysis of the chimeric state in mice. 3. Comparison of the colonizing capacities of syngeneic cell suspensions from different sources.

Cytological analysis of the lymphoid organs of mice neonatally injected with syngeneic cell suspensions derived from different sources showed that the proportions of donor cells in the host spleen, thymus and bone marrow were low, irrespective of the type of suspension administered at birth. In contrast, the proportions of donor cells found in the host lymph nodes were for all inocula demonstrably higher than those found in other lymphoid organs. Various types of inocula, however, displayed different lymph node colonizing capacities depending upon the tissue from which the inoculum was prepared. The order of the lymph node colonizing properties showed a fair correlation with the known order of tolerance-conferring capacities of these inocula. Both phenomena are in accord with the hypothesis that the higher the content in recirculating small lymphocytes in a given tissue, the higher the capacity of the inoculum prepared from that tissue to colonize the host lymph node system and to induce tolerance.