Authors

¹ Strathclyde Institute of Pharmacy and Biomedical Sciences

Discussion

Trichinellosis is a human disease caused by infection with parasitic nematode Trichinella spiralis. It is estimated that more than one billion people are infected by the Trichinellosis. Infection in the intestine by T. spiralis is associated with a mastocytosis, an increased number of mast cells. These cells have been shown to be an essential role for successful worm expulsion of gastrointestinal worms through the release of a number of mediators, which provide a central function in host protection against these parasites. The function of mast cells in the expulsion of Trichinella spiralis has been investigated using mast cell deficient C-kit mutant models W/Wv. In addition to mast cell deficiency these mice have a number of other abnormalities including anaemia and a lack of interstitial cells of Cajal. Therefore, our aim is to examine if the observations of C-kit models could be replicated in other models of mast cell deficiency. To investigate the role of mast cells in parasitic infection, Wsh mice (C57BL6 background) and Mas-TRECK mice (BALB/c background) were infected with 400 larvae Trichinella spiralis. Wsh mice are a natural mutant in which has an inversion mutation in regulatory elements upstream of C-kit element that is the receptor for Stem Cell Growth Factor (SCF) and have fewer abnormalities than W/Wv. Mas-TRECK mice are a novel strain in which genetic modification that diphtheria toxin receptor (DTR) is inserted into the intronic enhancer (IE) of IL4. The progression of infection and immune responses generated were examined by counting numbers of worms, analysis of intestinal pathology and cytokine production along with antibody responses. The expulsion of Trichinella spiralis from Mas-TRECK mice was observed to be delayed in comparison to the background strain while Wsh mice found to be delayed parasite expulsion of Trichinella spiralis with significantly higher than those of C57BL/6 strains and was observed to mount a greater immune response against T. spiralis than the background strain with increased IgE antibody responses. Analysis of mucosal mast cell number in the small intestine and levels of mMCP-1 in the serum suggested that mast cells may not be completely ablated in Mas-TRECK mice following treatment with DT may not be completely mast cell-deficient. Therefore, further studies are required to evaluate the benefits of different mast cell deficient strains; particularly estimation of other abnormalities may potentially affect results.