Survival and tissue localization of xenogeneic human lymphocytes in hypothymic nude mice: observations in normal subjects and multiple sclerosis.

The feasibility of using the hypothymic nude mouse as a transfer system for the study of cellular autoimmunity, by injection and tracing of 51chromium (Cr) or fluorescein labelled lymphocytes from humans, allogeneic or syngeneic mice was investigated. The localization of the injected cells was studied by radioisotopic counting or microscopy. For mouse cells there was better survival of syngeneic than allogeneic cells, and the pattern of distribution of injected mouse lymphocytes differed markedly from that of xenogeneic human lymphocytes. Thus, the lymph nodes and spleen were the predominant sites of localization of transferred syngeneic (BALB/c) lymphocytes, indicative of long recirculation of these cells, whereas the liver was the predominant site of localization of transferred human lymphocytes, and there was no evidence for recirculation of these cells. In studies on patients with multiple sclerosis, lymphocytes did not localize in neural tissue. The data indicate that the nude mouse is unlikely to be useful for the study of the tissue distribution of dispersed xenogeneic (human) lymphocytes.