Role of the thymus in control of autoreactivity or allotolerance in syngeneic and allogeneic bone marrow chimeras treated with bacterial adjuvants
Taniguchi, K.; Gondo, H.; Nomoto, K.
Journal of Immunology 133(4): 1735-1739
1984
ISSN/ISBN: 0022-1767 PMID: 6088626 Document Number: 231135
Thy-1-bone marrow (BM) cells from C57BL/6 (B6) mice were transferred into thymectomized or nonthymectomized syngeneic B6 .fwdarw. B6, allogeneic B6 .fwdarw. C3H or semiallogeneic B6 .fwdarw. (B6 .times. C3H)F1, irradiated mice after which bacterial substances (BCG or Bordetella pertussis chimeras that had been left without BCG treatment, irrespective of host/donor combination or thymectomy. The development of wasting syndrome as well as autoreactivity in BCG-treated B6 .fwdarw. B6 mice could be prevented by thymectomizing the recipients before reconstitution or co-cultivating the donor BM cells with syngeneic spleen cells before reconstitution of nonthymectomized recipients. In the allogeneic or semiallogeneic combinations, the BCG treatment resulted in a wasting syndrome and CML/MLC reactivity toward C3H or (C3H .times. B6)F1 host-derived cells irrespective of thymic presence or absence. No breakdown of allotolerance was retarded in the thymectomized mice, and it could be prevented by co-cultivation of donor BM cells with splenocytes of recipient genotype only if the cells were used to reconstitute thymectomized recipients. The breakdown of allotolerance in B6 .fwdarw. C3H chimera was never accompanied by autoreactivity against B6 target cells. Thus, induction of autoreactivity and GvH in BCG-treated syngeneic BM chimeras, probably reflecting the breakdown of autotolerance, is strictly thymus dependent. In contrast, induction of anti-host reactivity in BCG-treated allogeneic chimeras may occur in the absence of a thymus and without concomitant autoreactivity, suggesting 2 independent levels of controls: 1 that is thymus dependent for the breakdown of auto- as well as allotolerance, and 1 that is thymus independent, unique for the breakdown of allotolerance.