Inflammatory response during the muscle phase of Trichinella spiralis and T. pseudospiralis infections

Abstract

An attempt was undertaken to determine whether a concurrent infection of Trichinella spiralis and T. pseudospiralis can reduce cellular in®ltrations against the former species during the muscle phase of worm development. BALB/c, nude and CBA/N mice were orally infected with either species or a mixture of both. New-born larvae (NBL) of either or both species were also injected subcutaneously into the right/left leg of BALB/c mice. In T. spiralis oral infection, myositis was strongest in BALB/c, intermediate in CBA/N and weakest in nude mice. In T. pseudospiralis oral infection, slight cellular in®ltrations were observed around the worms in BALB/c but not in nude or CBA/N mice. However, in mixed oral infections of two species, in®l-trations around the sites of T. spiralis were not reduced. In mice injected with T. pseudospiralis NBL, in®ltrations around the infective-stage larvae were mostly absent. However, in mice injected with T. spiralis NBL, prominent granulomatous reactions were observed near the sites of worms. The tissue reaction was substantially stronger than that in oral infections. In mice injected with NBL of both species (into dierent legs), a heavy in®ltration was also observed at the site of T. spiralis. A marked increase in levels of IL-4 and IL-6 was detected in the popliteal lymphocytes of BALB/c mice injected with either live or dead NBL of T. spiralis at days 15 and 20 post-injection. This indicated that the worms mainly elicited a T H 2 response during the muscle phase of development. An indirect¯uorescent antibody test and laser confocal microscopic studies demonstrated the presence of CD4 and CD8 cells in the cytoplasmic region of the nurse cell complex of T. spiralis.

Regulation of host immune cells and cytokine production induced byTrichinella spiralisinfection

“…The inflammatory and immune responses after 3 dpi helped to reduce the damage caused by parasites and establish long-term parasitism. The level of Th2 response in the spleen from 6 dpi was also significantly increased, which was consistent with published studies on T. spiralis immunology which show that infection induces a Th2-type-dominated immune response in the host [3, 18]. This reflects the complexity of host immune regulation in the early stages of Trichinella infection.…”

Immune responses in mice vaccinated with a DNA vaccine expressing serine protease-like protein from the new-born larval stage ofTrichinella spiralis

“…During T. spiralis intestinal infection, CD4 + Th2 cells are critical in host protective immune and inflammatory responses (Ha et al 1983; Khan et al 2001). However, at muscular phase of T. spiralis infection, Th1 mediated the destructive granulomatous response, while Th2 are largely not destructive to ML (Li and Ko, 2001; Beiting et al 2007). Furthermore, Th2-type response will inhibit the Th1-type response.…”

Characterisation of the Trichinella spiralis Deubiquitinating Enzyme, TsUCH37, an Evolutionarily Conserved Proteasome Interaction Partner

“…Female adult worms release newborn larvae that cross the intestinal epithelia and enter the circulation, in which they are transported to skeletal muscle. The number of larvae ingested and their path taken en route to the skeletal muscle tissues determines the potential for acute illness, whereby infection and inflammation of the eyes, heart or CNS may result in myalgia, vasculitis, myocarditis and encephalitis, occasionally leading to fatality [6], [7]. In order to establish chronic infection, parasites invade fully differentiated skeletal myofibres.…”