Antibody‐mediated in‐vivo cytotoxicity to Trichinella spiralis newborn larvae in immune rats

Abstract

The antibody-dependent cell-mediated larvicidal response of AO rats against Trichinella spiralis newborn larvae was studied in vivo. Rats were immunized with 2000-3000 muscle larvae orally and then challenged 6-20 days later with 10,000-20,000 newborn larvae intraperitoneally. Newborn larvae recovery from the peritoneal cavity decreased significantly and was accompanied by cuticular cell adherence and killing of newborn larvae by day 9 of infection. Similar effects were observed when newborn larvae were incubated with blood obtained from immunized rats. The cell adherence and larvicidal responses reached their peak by day 16 of the primary infection. Passive transfer experiments demonstrated that newborn larvae infectivity was substantially impaired once cell adherence occurred. Cuticular adherence took place in vitro only when immune serum was added to the incubation medium. Complete destruction of newborn larvae in vivo after passive transfer, as measured by muscle larvae burden was only evident after exposure to both immune serum and immune cells, not to either alone. Non-specific stimulation of the peritoneal cavity with a sterile intestinal infection failed to induce cuticular adherence or larval killing in these rats. We conclude that a stage-specific antibody-dependent cell-mediated larvicidal response is rapidly generated in vivo after the host is exposed to newborn larvae. It is a systemic response which impairs the infectivity of newborn larvae and can destroy them before they reach muscle tissue.

Trichinella spiralis : in vitro cytotoxicity of peritoneal cells against synchronous newborn larvae of different age

“…These antigens are stage speci®c and also abundant in both excretions/secretions and on the larval cuticular surface. Wang and Bell (1988) demonstrated that antibodies were produced during the early immune response against NBL, and antibody-mediated cell adherence to NBL signi®cantly inhibited the infectivity of older T. spiralis NBL. Therefore, the decrease in infectivity of older sNBL mentioned by Wranicz et al (1998b) corresponds to the results obtained here in the ADCC test, where the percentage of killed sNBL rose after 24 h.…”

“…Wang and Bell (1988) demonstrated that NBL possessed similar infectivity up to 24 h of age, but Binaghi et al (1985) and GansmuÈ ller et al (1987) showed the highest infectivity by 20-h-old NBL. The results obtained by Wranicz et al(1998b) revealed that greatest infectivity was observed when larvae were up to 10 h old.…”

Trichinella spiralis reinfection: changes in cellular and humoral immune response in BALB/c mice

“…Larvae survive in nurse cells in close association with macrophages, CD8+ and CD4+ T lymphocytes, and B lymphocytes (Beiting et al, 2004). B lymphocytes secreting antibodies, particularly IgG and IgE, may lead to an effecttive antibody-dependent cell mediated cytotoxic reaction against T. spiralis newborn larvae (Moloney & Denham, 1979;Wang & Bell, 1988;Dvorožňáková et al, 2010). Our study was aimed at development of T-cell response and specific antibody response in mice after reinfection with larvae of Trichinella spiralis in relation to the parasite burden.…”

Kinetics of specific humoral immune response of mice infected with low doses of Trichinella spiralis, T. britovi, and T. pseudospiralis larvae

“…Parasites survive in nurse cells in close association with macrophages, CD8+ and CD4+ T lymphocytes, and B lymphocytes (Beiting et al, 2004). B lymphocytes secreting antibodies, particularly IgG and IgE, may lead to an effective antibody-dependent cell mediated cytotoxic reaction against T. spiralis newborn larvae (Moloney & Denham, 1979;Wang & Bell, 1988). The earlier specific antibodies are bound to Trichinella antigens and form immune complexes, which are present in infected host at the beginning of the infection (Dziemian & Machnicka, 2000;Feldmeier et al, 1987).…”