Regulation of T-cell proliferative responses by cells from solid lung tissue of M. tuberculosis-infected mice.

We have studied proliferative responses to mycobacterial antigen preparation (PPD) and to non-specific stimuli of interstitial cells from the lungs of Mycobacterium tuberculosis-infected CBA mice. PPD-reactive lymphocytes appeared in the lung wall tissue in the course of chronic infection, but their proliferative capacity was totally inhibited by the lung macrophages. The latter were also able to suppress the proliferation of immune lymph node T cells. The mechanism of suppression clearly had two components, one being infection-specific and the other non-specific. Non-specific suppression was mediated mainly by prostaglandin E(PGE), whereas the specific mechanism showed only a weak influence of PGE and depended on the presence of I-J+ Lyt-2- nylon-wool-adherent cells in the responder population. Interstitial lung T or B lymphocytes were not involved in specific suppression.