This study deals with the effect of natural thymocytotoxic autoantibody (NTA) of NZB mouse serum and of specifically prepared antilymphocyte serum upon the tissue distribution of 51Cr-labeled mouse lymph node cells in syngeneic recipients. By cytotoxicity test both sera were found to be cytotoxic for the same population of lymph node cells, which were believed to be thymus dependent lymphocytes (T-cells). C57BL/6J mice were injected intravenously with syngeneic 51Cr-labeled lymph node cells which had been previously incubated at 4°C for 60 min with either of these sera, in the absence of complement, or with normal control sera. Twenty-four hours after injection, a substantial decrease in migration to lymph nodes and spleen and an increase in migration to liver were observed with 51Cr-labeled cells which had been treated with either the NTA-positive NZB mouse serum or the antilymphocyte serum as compared with control groups. These findings are consistent with the hypothesis that NTA has a causal relation to the observed age decrease of recirculating T-cells in NZB mice and that T-cell depletion is mediated by a continuous process of autosensitization phagocytosis.
This work was supported by grants from the National Institute for Arthritis and Metabolic Disease, National Institutes of Health, the Susan Greenwall Foundation, Inc., and the Virginia and D. K. Ludwig Foundation, Inc. This work is Research Department Publication 445.