Abstract
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 immunooglobulin-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 γ 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.
Original language | English (US) |
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Pages (from-to) | 775-779 |
Number of pages | 5 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 88 |
Issue number | 3 |
State | Published - 1991 |
Externally published | Yes |
Keywords
- Cell differcntiation
- Cell-cell interaction
- Directed secretion
- Double immunofluorescence microscopy
ASJC Scopus subject areas
- General