Genetic control of the in vitro responses of rat blood lymphocytes. I. Comparison of in vitro and in vivo responses.

Nielsen, H. E. & Koch, C. Genetic Control of the In Vitro Responses of Rat Blood Lymphocytes. I. Comparison of In Vitro and In Vivo Responses, Scand. J. Immunol. 4, 31-36, 1975. In vitro DNA synthetic responses of blood lymphocytes from the inbred rat strains BN, Lewis, and AS were compared with each other after stimulation with allogeneic lymphocytes, human lymphocytes, phytohemagglutinin, and anti-Ig antibodies. BN lymphocytes responded less well than AS and Lewis lymphocytes regardless of the stimulus used. The responses of the congenic strains Lewis and Lewis. BN were identical, suggesting that H-1 (Ag-B)-linked loci do not determine in vitro responsiveness in these strains. In vivo, AS and BN rats were equally able to reject third-party skin grafts and to induce graft-versus-host reactions in F1 hybrids. We conclude that the interstrain differences found in vitro reflect genetically determined differences in in vitro kinetics, possibly related to the fraction of short-lived lymphocytes present rather than to demonstrable differences in the frequency of reactive lymphocytes.