SUPPRESSOR CELLS INDUCED BY BCG RELEASE NON-SPECIFIC FACTORS INVITRO WHICH INHIBIT DNA-SYNTHESIS AND INTERLEUKIN-2 PRODUCTION

  • 1 January 1984
    • journal article
    • research article
    • Vol. 51  (1) , 65-71
Abstract
Mice injected i.v. with a high dose (5 .times. 107) of BCG failed to develop delayed hypersensitivity to BCG. Spleen cells from these mice released factors on culture which suppress DNA synthesis induced by concanavalin A [Con A] in vitro. Cell separation experiments showed that macrophages and T cells produce inhibitory factors. The macrophage factor had a MW of 10,000-30,000; the T cell factor had a MW of 50,000-70,000. Further evidence that these 2 factors are different was provided by the kinetics of their action. The T cell factor only acted when given within 12 h of stimulation with Con A; the macrophage factor acted even when given at 48 h. In the case of the T cell factor, the inhibition of DNA synthesis may be attributed to its ability to block the interleukin 2 production induced by Con A. As similar T cell and macrophage factors are produced in mice responding to simple chemically reactive haptenes (contact sensitizers), it is possible that a similar suppressor circuit is involved in the control of the response to contact sensitizers and in the production of unresponsiveness (anergy) in mice given large doses of BCG.