期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：3
页码：1195-1199
DOI：10.1073/pnas.74.3.1195
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Previous chemical studies attempting to demonstrate Ia antigens on mouse thymocytes have given contradictory results. We attempted to resolve the question of whether Ia antigens exist on thymocytes (defined as thymus cells that bear a T cell marker) by isolating strain C3H thymocytes free of other contaminating cells using the fluorescence-activated cell sorter, and then chemically testing the purified populations for Ia antigens. Immunoglobulin-negative thymus cells and thymus cells selected with a rabbit antiserum to mouse brain were the two populations of thymocytes labeled with [3H]leucine after sorting. Radiolabeled proteins were solubilized with the non-ionic detergent Nonidet P-40, reacted with anti-Ia antiserum, and analyzed by electrophoresis on discontinuous sodium dodecyl sulfate/polyacrylamide gels. Ia antigens were recovered from both cell populations. These antigens were synthesized by thymocytes and were found on molecules composed of two chains of molecular weight 33,000 and 25,000, respectively, similar to Ia antigens derived from spleen cells. Assuming that all thymocytes bear similar amounts of Ia antigens, we estimated that they have approximately 1/50 the amount of Ia antigens that spleen cells do.
