Deficit of interleukin 2 production associated with impaired T-cell proliferative responses in Mycobacterium lepraemurium infection.
C57BL/6 and BALB/c mice were infected intravenously with 10(7) Mycobacterium lepraemurium (MLM). At various times after infection, spleen cells were tested for their capacity to proliferate in vitro in response to concanavalin A (ConA) and to allogeneic cells. The generation of alloreactive cytotoxic T lymphocytes was also studied. The mitogen- and allogeneic-cell-induced blastogenesis of splenocytes from MLM-infected C57BL/6 and BALB/c mice was shown to be depressed during infection. The maximal decrease occurred 6 months after infection. Conversely, no reduction in the ability to generate alloreactive cytotoxic T lymphocytes was observed even after 6 months of infection. At the same time, interleukin 2 (IL2) activity generated by ConA stimulation of infected splenocytes was measured in both strains. IL2 activity in the ConA-stimulated culture supernatants was decreased as early as 1 month after MLM inoculation as compared with supernatants from age-matched control mice. Thus, IL2 production by infected-mouse spleen cells was shown to decline earlier than their proliferative responses to ConA and to allogeneic cells. ConA-induced T-cell blasts from infected mice showed a reduced ability to proliferate when incubated with an IL2-containing reference supernatant from ConA-stimulated normal spleen cells. These data suggest that a defect in IL2 production and utilization might contribute to the impairment of T cell-mediated immunity observed in MLM-infected mice.
D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000276:immunology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009164:Mycobacterium Infections / Q000276:immunology*; D009167:Mycobacterium lepraemurium; D013045:Species Specificity; D013154:Spleen / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic
D007376:Interleukin-2; D003208:Concanavalin A