Trichinella spiralis: killing of newborn larvae by lung cells

Abstract

The migratory stage of Trichinella spiralis, the newborn larva (NBL), travels along the pulmonary microvascular system on its way to the skeletal muscle cells. The present work studies the capability of lung cells to kill NBL. For this purpose, in vitro cytotoxicity assays were performed using NBL, lung cell suspensions from Wistar rats, rat anti-NBL surface sera, and fresh serum as complement source. The cytotoxic activity of lung cells from rats infected on day 6 p.i. was compared with that from noninfected rats. Two and 20 h-old NBL (NBL2 and NBL20) were used as they had shown to exhibit different surface antigens altering their biological activity. Sera antibodies were analyzed by indirect immunofluorescence assay, and cell populations used in each assay were characterized by histological staining. The role of IgE in the cytotoxic attack against NBL was analyzed using heated serum. The FcεRI expression on cell suspensions was examined by flow cytometry. Results showed that lung cells were capable of killing NBL by antibody-dependent cell-mediated cytotoxicity (ADCC). Lung cells from infected animals yielded the highest mortality percentages of NBL, with NBL20 being the most susceptible to such attack. IgE yielded a critical role in the cytotoxic attack. Regarding the analysis of cell suspensions, cells from infected rats showed an increase in the percentage of eosinophils, neutrophils, and the number of cells expressing the FcεRI receptor. We conclude that lung cells are capable of killing NBL in the presence of specific antibodies, supporting the idea that the lung is one of the sites where the NBL death occurs due to ADCC.

Characterization of a serine protease inhibitor from Trichinella spiralis and its participation in larval invasion of host’s intestinal epithelial cells

“…Previous studies demonstrated that ADCC-mediated destruction of T. spiralis NBL was dependent on specific anti- Trichinella IgG [ 62 , 63 ]. Cytotoxicity against NBL in the lungs of T. spiralis- infected mice was found to be IgE-mediated by Falduto et al [ 64 ]. To investigate the cytotoxicity of anti-rTsSPI antibodies, an in vitro ADCC test was also performed in the present study.…”

Influence of adjuvant formulation on inducing immune response in mice immunized with a recombinant serpin from Trichinella spiralis

“…Research both in vivo and in vitro has proved that eosinophil‐damage and neutrophil‐mediated damage of new‐born larvae (NBL) of T. spiralis are dependent on parasite‐specific IgG . Cytotoxic attack against NBLs in the lung of infected mice is IgE dependent . It has been reported that IgM involved in dislodging several kinds of worms.…”

“…33 Cytotoxic attack against NBLs in the lung of infected mice is IgE dependent. 34 It has been reported that IgM involved in dislodging several kinds of worms. For example, IgM antibodies were protective against S. stercoralis, Brugia pahangi and Brugia malayi.…”

Cellular and molecular changes and immune response in the intestinal mucosa during Trichinella spiralis early infection in rats

“…Newborn larvae (NBL) were obtained as described previously [21]. Briefly, AW were recovered from the intestine of rats 5-6 days after oral infection with 7000 ML.…”