Mucosal T cells provide helper function but do not proliferate when stimulated by specific antigen in lymphogranuloma venereum proctitis in nonhuman primates.
To study antigen-specific immune responses of gut-associated T lymphocytes after gastrointestinal infection, Cynomolgus monkeys were inoculated rectally with Chlamydia trachomatis of the L2 [lymphogranuloma venereum (LGV)] strain. Infected monkeys developed a chronic proctitis with the appearance of LGV-specific immunoglobulin G-antibodies in the serum. Lymphocytes isolated from the peripheral blood, the spleen, and draining lymph nodes had a vigorous antigen-specific proliferative response to LGV in vitro. Both T and B cells proliferated in response to stimulation with LGV, but B-cell proliferation was T-cell-dependent, as shown by cell separation techniques and cell-cycle analysis with dual-laser flow cytometry. Lymphocytes isolated from both involved and uninvolved lamina propria did not proliferate in response to LGV stimulation, whereas mitogen-induced proliferation was not different in lamina propria lymphocytes and the other lymphocyte populations. This lack of antigen-specific proliferation was not caused by a suppressor effect of mucosal T cells or monocytes or the absence of antigen-presenting cells. In contrast, lamina propria T lymphocytes from infected animals were able to provide antigen-specific help for polyclonal immunoglobulin synthesis by immune B lymphocytes after stimulation with LGV. Thus, in LGV proctitis in monkeys, mucosal antigen-reactive T cells differ from lymphocytes in other sites in that they can provide helper function, but are not able to proliferate in response to LGV antigens.
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000276:immunology; D003208:Concanavalin A / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes; D005260:Female; D005434:Flow Cytometry; D007136:Immunoglobulins / Q000096:biosynthesis; D007413:Intestinal Mucosa / Q000276:immunology*; D008213:Lymphocyte Activation; D008219:Lymphogranuloma Venereum / Q000276:immunology*; D008252:Macaca fascicularis; D008297:Male; D011349:Proctitis / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000939:Epitopes; D007136:Immunoglobulins; D003208:Concanavalin A