STIMULATED CHEMOTACTIC RESPONSE IN NEUTROPHILS FROM TRICHINELLA-PSEUDOSPIRALIS-INFECTED MICE AND THE NEUTROPHILOTACTIC POTENTIAL OF TRICHINELLA EXTRACTS

During infection with Trichinella pseudospiralis a strong neutrophil response is evident in the peripheral circulation of the mouse. This study compared the chemotactic response of neutrophils from uninfected, T. pseudospiralis-infected and Trichinella spiralis-infected mice to extracts from adult worms, newborn larvae and muscle-stage larvae of both species of parasite. The chemotactic response of neutrophils from T. pseudospiralis-infected mice to Zymosan-activated mouse serum (ZAMS) was significantly greater than that seen with neutrophils from either uninfected or T. spiralis-infected mice. Unstimulated chemotactic response of neutrophils from these three groups of animals to medium alone was similar. The chemotactic response of neutrophils from the three groups of animals was unaffected by either the concentration or source of serum. The chemotactic response of neutrophils from T. pseudospiralis-infected mice was significantly greater than that observed with cells from uninfected or T. spiralis-infected mice. Among parasite extracts, those from newborn larvae displayed the strongest chemotactic potential for neutrophils. Extracts from muscle larvae of T. spiralis and T. pseudospiralis and extracts of T. spiralis adult worms showed the weakest attraction for neutrophils. Extracts from adult T. pseudospiralis and from newborn larvae of both species elevated the chemotactic response of uninfected mouse neutrophils to a significantly greater level than that seen with ZAMS alone, while a significant reduction in this response was evident only when ZAMS was presented to neutrophils with 500-mu-g of extract from muscle larvae of T. pseudospiralis or T. spiralis. These results demonstrate that neutrophils isolated from T. pseudospiralis-infected mice appear in general to be chemotactically hyperresponsive compared to neutrophils recovered from uninfected or T. spiralis-infected mice and that extracts of adult worms and newborn larvae of T. pseudospiralis exhibit strong neutrophil chemotactic potential. These phenomena may underlie the strong neutrophil response characteristic of infections with this species of Trichinella.