Protein deficiency impairs ADCC mechanism against NBL in lungs during Trichinella spiralis infection

VILA, CC; SARACINO, MP; LOMBARDO, T; FALDUTO, GH; DIAZ, M; PALLARO, A; BALDI, PC

Ciudad del Cabo

Simposio; Keystone Symposium Helminths: New Insights from Immunity to Global Health; 2019

Keystone Symposia

On their way to skeletal muscle cells, Trichinella spiralis newborn larvae (NBL) travel along the lungs, among other sites. Our previous studies demonstrated that lung mucosa leukocytes can kill NBL by ADCC mechanism. In rats fed a protein deficient diet (PD), we observed an impaired mucosal immune response in intestine and lungs. The aim of this work was to assess the effect of the PD diet during T. spiralis infection on ADCC ex vivo using lung cell suspensions (LCS). For that purpose, two groups of weaning Wistar rats received PD diet (6.5% casein) and other two received control diet (C, 20% casein); 10 days later one group of each diet was orally infected (PDI, CI). Animals were euthanized at 6 and 13 days p.i. to obtain LCS and lung tissue extracts (LTE). Antibodies (Abs) against NBL in LTE, rat cytotoxic sera (RCS, positive control) and non-infected rat sera (NIRS, negative control) were measured by indirect IFA. LCS were concentrated and stained with Giemsa to determine the leukocyte formula. In ADCC assays, NBL were incubated with LCS from infected or non-infected rats (PD, C) or peritoneal cells from non-infected C rats in the presence of LTE, RCS or NIRS, and NBL mortality percentage (%M) was evaluated. Titers of specific Abs in LTE were lower in PDI than CI. In ADCC assays with peritoneal cells, %M was lower with LTE from PDI compared to CI at day 13 p.i. (21.2±2.83 vs. 29.66±2.22, P