Trypanosoma cruzi attachment to lymphocyte muscarinic cholinergic and beta adrenergic receptors modulates intracellular signal transduction.
Plasma membrane vesicles of Trypanosoma cruzi (PMVs) formed saturation binding isotherms with naive murine T lymphocytes. Parasite membrane attachment to the muscarinic cholinergic receptors of Lyt 2.2+T cells (suppressor cells) resulted in the synthesis of cGMP, attenuation of cAMP levels and in the secretion of prostaglandin E2, an immunoregulator effector substance. These T suppressor cell signals were blunted by atropine and by monospecific antibody against T. cruzi surface epitopes. The interaction of T. cruzi PMVs with the beta adrenergic receptors of Lyt L3T4+T cells (helper cells) resulted in the synthesis of cAMP and in the attenuation of cGMP levels. T helper cells did not secrete prostaglandin E2 when T. cruzi PMVs were added to this system. These T helper cell signals were blunted by propranolol and by monospecific antibody against T. cruzi surface epitopes. The interaction of T. cruzi with T lymphocytes may result, therefore, in the down-regulation of the immune response induced by prostaglandin E2 T suppressor cell secretion and by cAMP inhibition of proliferation of T helper cells.
Borda
E S
ES
Centro de Estudios Farmacologicos y de Botanica, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires, Argentina.
Sterin-Borda
L J
LJ
Pascual
J O
JO
Gorelik
G
G
Felix
J C
JC
von Kreuter
B F
BF
Santos-Buch
C A
CA
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology / Q000469:parasitology*; D002448:Cell Adhesion; D002462:Cell Membrane / Q000469:parasitology; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D011976:Receptors, Muscarinic / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology; D013601:T-Lymphocytes / Q000469:parasitology*; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism / Q000469:parasitology; D006377:T-Lymphocytes, Helper-Inducer / Q000469:parasitology; D050378:T-Lymphocytes, Regulatory / Q000378:metabolism / Q000469:parasitology; D014349:Trypanosoma cruzi / Q000502:physiology*
D011943:Receptors, Adrenergic, beta; D011976:Receptors, Muscarinic; D000242:Cyclic AMP; D006152:Cyclic GMP; D015232:Dinoprostone