Activation and signaling status of human lamina propria T lymphocytes.
In this study, proliferative responses of human lamina propria T lymphocytes were examined in vitro. The response of lamina propria T lymphocytes to Sepharose-bound anti-CD3 antibody plus interleukin 2 was significantly lower than the response of autologous peripheral blood T lymphocytes, whereas the responses of lamina propria T lymphocytes to anti-T11(2/3) antibodies plus sheep erythrocytes or anti-CD28 antibody plus interleukin 2 were largely preserved. After coculture with mucosa supernatant, peripheral blood T lymphocytes showed a similar pattern of reactivity as lamina propria T lymphocytes. This reduced reactivity to T-cell antigen receptor stimulation appears to exist at the level of signal transduction, because triggering of CD3 induces low amounts of intracellular inositol 1,4,5-triphosphate and no free calcium increase in lamina propria T lymphocytes when compared with peripheral blood T lymphocytes. This study indicates that the antigen receptor-dependent activation pathway of lamina propria T lymphocytes for proliferation is down-regulated by intestinal mucosa derived factor(s) and that the alternative pathways mediated by CD2 or CD28 are largely preserved. Based on previous data that lamina propria T lymphocytes can provide help to B cells, it is possible that these alternative activation pathways play an important role in T-B cell interaction in the gut.
Qiao
L
L
Department of Applied Immunology, German Cancer Research Center, Heidelberg.
Schürmann
G
G
Betzler
M
M
Meuer
S C
SC
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology; D001769:Blood / Q000276:immunology; D002455:Cell Division / Q000502:physiology; D003106:Colon / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D007376:Interleukin-2; D007413:Intestinal Mucosa / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000502:physiology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D007376:Interleukin-2