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：1991
卷号：88
期号：3
页码：775-779
DOI：10.1073/pnas.88.3.775
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：We describe the intracellular localization, by double immunofluorescence microscopy, of four cytokines that were produced during the prolonged interaction of cloned helper T cells with resting splenic B cells. When two rabbit immunoglobulin-specific helper-T-cell clones were mixed, either separately or together, with splenic B cells in the presence of the antigen rabbit anti-mouse immunoglobulin antibodies, stable T-cell-B-cell conjugates were seen up to 29 hr later. Microscopic observations of these cells revealed that interferon gamma and interleukin 2, inside one of the T-cell clones, and interleukins 4 and 5, inside the other T-cell clone, were concentrated very close to the T-cell-B-cell contact area. The cytokines were not seen in the T cells prior to their interaction with the B cells and their production was strictly antigen-specific. These studies show, at the single-cell level, that helper-T-cell clones can remain bound to splenic B cells long enough for the T cells to produce cytokines, which are synthesized near the bound B cells. We propose that the polarized synthesis of the cytokines may result in their directed secretion toward the bound B cells. By locally secreting the cytokines, which are not antigen-specific, at the contacting T-cell-B-cell membranes, where T- and B-cell surface receptors are engaged and clustered, the helper T cells can induce selective and specific B-cell responses.
