title: IgA from HIV+ haemophilic patients triggers intracellular signals coupled to the cholinergic system of the intestine.
abstract: IgA was obtained from HIV-infected haemophilic patients and the intracellular signals triggered by its reaction with isolated rat intestinal strips were studied. HIV+ IgA stained intestinal microvilli with a granular immunofluorescence pattern and bound to the muscarinic acetylcholine receptor (mAChR), displacing the specific muscarinic cholinergic antagonist QNB in a non-competitive manner. It triggered the signals that are the consequence of mAChR stimulation in the intestine. Thus, it decreased cAMP synthesis and increased guanosine 3':5'-cyclic monophosphate (cGMP) formation and phosphoinositide (PI) turnover of the intestine. In addition, it stimulated prostaglandin E2(PGE2) synthesis by intestinal strips. Through its effect on PGE2 synthesis, HIV+ IgA could have a dual action. On the one hand, it could enhance immunosuppression at a local level, favouring pathogen growth and subsequent intestinal dysfunction. On the other hand, PGE2 could directly increase intestinal motility and electrolyte/fluid loss. Both effects could be involved in intestinal damage in AIDS.
authors.affiliation: CEFYBO-CONICET and School of Dentistry, University of Buenos Aires, Argentina.
authors.forename: M E
authors.initials: ME
authors.lastname: Sales
authors.forename: L
authors.initials: L
authors.lastname: Sterin-Borda
authors.forename: M M
authors.initials: MM
authors.lastname: de Bracco
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez
authors.forename: M
authors.initials: M
authors.lastname: Narbaitz
authors.forename: E
authors.initials: E
authors.lastname: Borda
mesh_terms: D000818:Animals; D017615:Enteric Nervous System / Q000276:immunology*; D015658:HIV Infections / Q000150:complications / Q000276:immunology*; D006467:Hemophilia A / Q000150:complications / Q000276:immunology*; D006801:Humans; D018928:Immunity, Mucosal; D007070:Immunoglobulin A / Q000276:immunology* / Q000494:pharmacology; D007413:Intestinal Mucosa / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D011976:Receptors, Muscarinic / Q000276:immunology / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects / Q000276:immunology*
chemical_list: D007070:Immunoglobulin A; D011976:Receptors, Muscarinic