LYMPHOCYTE MUSCARINIC CHOLINERGIC ACTIVITY AND PGE(2) INVOLVEMENT IN EXPERIMENTAL TRYPANOSOMA-CRUZI INFECTION

In this paper, we demonstrated that the production of PGE(2) by CD8(+) T lymphocytes through muscarinic cholinergic receptor (mAChR) activat ion of lymphocytes from mice acutely infected with nonlethal Trypanoso ma cruzi CA-1 strain could enhance resistance to infection. Treatment in vivo with either atropine or cyclooxygenase inhibitors enhanced mor tality rates and parasitemia of mice infected with T. cruzi CA-1 strai n. The mechanism by which CD8(+) T lymphocytes released PGE(2) appears to involve the activation of the cells by circulating IgG present in mice infected with T. cruzi CA-1 strain. Binding of these antibodies t o mAChR on CD8(+) T lymphocytes triggered the release of large amounts of PGE(2). The results point to a role of serum antibodies against mA ChR in the protection of T. cruzi infection. The prostanoid acting as an immunomodulator contributed to the maintenance of the chronic cours e of experimental Chagas disease. (C) 1996 Academic Press, Inc.