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：1973
卷号：70
期号：10
页码：2879-2883
DOI：10.1073/pnas.70.10.2879
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Surface proteins of mouse thymus and spleen cells were radioiodinated with lactoperoxidase. After solubilization, the labeled proteins were precipitated by antibodies directed against mouse immunoglobulin chains; the precipitates were analyzed by radioautography after Na dodecyl sulfate-gel electrophoresis. Radioactive {micro} and L chains were absent from thymocyte extracts and conspicuous in spleen-cell extracts. The following cells were biosynthetically labeled for 4 hr [35S]methionine or 24 hr with [14C]leucine: (1) Thymocytes, (2) cortisoneresistant thymocytes [both treated with rabbit antisera cytotoxic to bone marrow-derived (B) lymphocytes and IgM-containing plasma cells, to kill possible contaminating nonthymus-derived cells], (3) "activated thymocytes" (allogeneic cell cultures of cortisone-resistant thymocytes), (4) human Daudi cells (a B lymphoblastic cell line), and (5) purified mouse B spleen lymphocytes devoid of plasma cells. Again no {micro} and L chains could be detected in thymocyte or thymus-derived cell extracts by immune precipitation and gel electrophoresis, while these chains were conspicuous in B-cell extracts. "Educated thymocytes," obtained from spleens of lethally irradiated mice injected with syngeneic thymocytes and antigen, synthesized {micro} and L chains under similar conditions; this synthesis resulted from contamination of these cells by IgM-containing plasma cells.
