Role of serum and mucosal antibodies in cellular cytotoxicity mechanism during Trichinella spiralis infection in protein deficient rats

BALDI, PC; SARACINO, MP; PALLARO, AN; VILA, CC; FALDUTO, GH

Congreso; LXIII Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC), LXVI Reunión Científica Anual de la Sociedad Argentina de Inmunología (SAI) y Reunión Anual de la Sociedad Argentina de Fisiología (SAFIS); 2018

We have previously demonstrated that protein deficient rats infected with Trichinella spiralis suffer a severe infection with a delayed expulsion of adult worms (AW) from the gut and a higher parasite burden in muscles.Intestinal Trichinella-specific IgE and IgA are known to reduce the fecundity of the AW.The aim of this work was to analyze the effect of a protein deficient diet on the production of intestinal anti-Trichinella antibodies and on AW fecundity index.Weaning Wistar rats received protein deficient (PD, 6.5% casein) or control (C, 20% casein) diets. After ten days, both groups were orally infected with T. spiralis muscle larvae (PDI and CI groups, respectively). Intestine tissue extracts were obtained (PERFEXT method) and specific antibodies against AW excretory/secretory products (AW-ESP) were detected by ELISA. To determine the fecundity index AW were obtained from the intestine of PDI and CI groups and were incubated during 3 h in RPMI medium. Female AW and newborn larvae (NBL) shed by female AW were counted. The fecundity index was calculated as the number of NBL/female AW. Results were analyzed using the two-way ANOVA test.All antibody isotypes against AW-ESP were increased in intestinal extracts of the CI group but only IgG2a had a significant rise in PDI. The PDI group had a higher fecundity index than CI starting at day 9 p.i. (30.58 ± 3.39 vs. 14.32 ± 2.95, NBL/female AWP< 0.05). At day 20 p.i., only the AW obtained from the PDI group continued to release NBL (14.05±2.30 vs. 0.00±0.00 NBL/female AWP< 0.05). Overall, these results suggest that the higher parasite burden previously found in the PDI group may be associated with the longer persistence of AW in the intestine and the higher fecundity index of female AW due to the lower specific immune response in these animals.