T cells of the human intestinal lamina propria are high producers of interleukin-10.
OBJECTIVE
Some of the recently observed functional features characteristic of immunocompetent cells residing in the human intestinal lamina propria could be mediated by interleukin-10 (IL-10). To investigate the role of IL-10 in the human intestinal mucosa, the regulation of IL-10 production by lamina propria T lymphocytes (LPL-T) was determined and compared with that of peripheral blood T lymphocytes (PBL-T).


METHODS
Following activation by using different stimuli, IL-10 release by LPL-T and PBL-T into the supernatant was measured by enzyme linked immunosorbent assay (ELISA). In parallel, cell growth was determined by [3H]-thymidine incorporation.


RESULTS
Neither LPL-T nor PBL-T release IL-10 constitutively. Triggering through CD2 or the T cell receptor (TCR)/CD3 complex in the presence of autologous monocytes induces significantly greater IL-10 secretion by LPL-T than by PBL-T. Engagement of the CD45 receptor enhances IL-10 release and proliferation of CD2 triggered CD45RO+ PBL-T. In contrast, it reduces CD2 induced IL-10 production by LPL-T without altering cell growth significantly.


CONCLUSIONS
Activated LPL-T release relatively high amounts of IL-10. Enhanced IL-10 production by activated LPL-T, in comparison with activated PBL-T, is not only related to the presence of a higher proportion of CD45RO+ T cells in the intestinal lamina propria, but is also caused by increased sensitivity of LPL-T to CD2 co-stimulation. The differential responsiveness of LPL-T, compared with PBL-T, to CD45 engagement demonstrates that CD45 could be involved in the altered CD2 reactivity of LPL-T.
Braunstein
J
J
Institute of Immunology, University of Heidelberg, Germany.
Qiao
L
L
Autschbach
F
F
Schürmann
G
G
Meuer
S
S
D001769:Blood / Q000276:immunology; D018801:CD2 Antigens / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016753:Interleukin-10 / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000276:immunology*; D017493:Leukocyte Common Antigens / Q000276:immunology; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D017260:Receptor-CD3 Complex, Antigen, T-Cell / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
D018801:CD2 Antigens; D017260:Receptor-CD3 Complex, Antigen, T-Cell; D016753:Interleukin-10; D017493:Leukocyte Common Antigens