The effect of immunomodulating drugs on the percentage of apoptotic and necrotic lymphocytes in inflammatory infiltrations in the muscle tissue of mice infected with Trichinella spiralis.

In order to determine the effect of apoptosis and necrosis on the intensity of the muscular phase of infection by Trichinella spiralis, male CFW mice were orally infected with T. spiralis larvae and treated with some immunomodulating drugs: calf thymus extract (TFX), lipopolysaccharide from Escherichia coli (LPS), and dexametasone (DEX). Treatment with TFX increased the proportion of apoptotic lymphocytes and decreased the proportion of necrotic lymphocytes from 14 to 60 days after infection in mice infected with T. spiralis. Treatment with LPS increased proportions of both apoptotic and necrotic lymphocytes from 21 to 60 days after infection, especially at 28 days after infection. Treatment with DEX increased the proportion of apoptotic lymphocytes only at 28 days after infection, and significantly increased the proportion of necrotic lymphocytes at 21 days after infection. Parasite load in the affected muscle tissue was significantly lower than the control in mice treated with TFX, not significantly different from the control in mice treated with LPS, and significantly higher than the control in mice treated with DEX. The results of the study suggest that the parasite made an effort to reduce the effectivity of the host immune response in order to ensure its own survival.