Protection of young rats from acute Trypanosoma cruzi infection by interferon-gamma given to their mothers during pregnancy

DÁVILA H; REVELLI S; DIDOLI G; BERNABO J; WIETZERBIN J; FALCOFF E; BOTTASSO O; BOTTASSO OSCAR

AMERICAN JOURNAL OF TROPICAL MEDICINE AND HYGIENE

AMER SOC TROP MED & HYGIENE

Lugar: Atlanta; Año: 1996 vol. 54 p. 660 - 664

0002-9637

Cytokinestimulation during fetal life could play a role in the differentiation andmaturation of immunocompetent cells. In this setting,  and because IFN-γ is a pleiotropiccytokine whose major effect is to modulate the function of a variety of celltypes, particularly those involved with the immune response,  we next investigated whether administration of IFN-γ to pregnant rats,infected or not with T.cruzi, was likely to protect offspring from thetrypanosomal infection further induced in them. Upon mating with syngeneicsires, four groups of 70-day old female "l" rats were subjected toone of the following procedures: treatment with recombinant rat IFN-γ 50,000IU/rat each  5 times/week during 3 weeks;infection with 1 x 106 trypomastigotes of T.cruzi at 7, 14,and 21 days after mating plus IFN-γ treatment as given to the former group; thesame protocol but IFN-γ injections being replaced by saline physiologic ones; injectionwith saline physiologic (first group schedule). Offspring were nursed by theirmothers until weaning and then infected with a similar dose of T.cruzi.Pregnant rats showed no exacerbated infection but a self-resolving milddisease, regardless they had received IFN-γ or not. Maternalinfection with T.cruzi and/or IFN-γ treatment caused noaffectation of gestation outcome. Nevertheless, offspring born to both groupsof IFN-γ-treated mothers (more strikingly those delivered by infected andIFN-γ treated mothers) appeared almost fully protected from their acuteinfection, and showed higher levels of anti-T.cruzi IgG antibodies whencompared with young born to their respective IFN-γ-untreated mothers.Measurements of IFN-γ serum activities indicated that ameliorated acute disease, inoffspring whose mothers were given IFN-γ during gestation,was not associated with increased levels of endogenously produced IFN-γ.