title: Intestinal Trichinella spiralis and Trichinella pseudospiralis in germfree and conventional mice.
abstract: By indirect hemagglutination (IHA) test in germfree (GF) and conventional (CV) mice, better antibody response was found in CV mice infected with 200 T. spiralis larvae. In contrast, when 500 larvae were used for infection, the response of GF mice exceeded that of CV controls. Humoral responses of GF and CV mice infected with single or mixed T. spiralis or T. pseudospiralis larvae were examined by IHA test with the use of both antigens and by determination of G1, A and M immunoglobulins. Cellular host response was studied only in T. spiralis infected mice by examination of the dynamics of intestinal mastocytes and T lymphocytes in lymphoid tissues and in the blood. Cellular inflammatory response was observed in the intestines and muscles of mice infected with single or mixed T. spiralis and T. pseudospiralis larvae in histopathological examinations. Antibody production was highest in T. spiralis infected CV, low in T. pseudospiralis infected mice and negative in mice with mixed infections. IgG1 and IgA levels were highest in T. spiralis and in mixed infections. In general they were higher in CV than in GF mice, however, the rate of increase was highest in all GF mice infected with T. spiralis and mixed larvae. The number of intestinal mastocytes was higher and their stimulation was earlier in GF than CV mice. The percentage of T lymphocytes was only slightly increased in GF and CV mice infected with T. spiralis as compared with control uninfected mice. Eosinophilia appeared to be characteristic of mice with T. spiralis infections and was higher in GF than CV mice. On the other hand, neutrophilia was characteristic of mice with T. pseudospiralis infections. All types of host response were compared with the dynamics of intestinal trichinellosis and expulsion time of adult worms. In general, GF mice expelled faster and harboured less intestinal trichinellae than CV animals. In experiments on CV Swiss mice in mixed infection, no suppression by T. pseudospiralis on the encapsulation process of T. spiralis larvae was noted. But T. spiralis larvae, irrespective of the number of T. pseudospiralis in the infective dose, always outnumbered the latter muscular larvae. This finding indicates the existence of antagonism between muscular larvae of both species. T. pseudospiralis appears to be immunogenically weaker showing a partial suppression of cellular and humoral host response in mixed infection especially.
mesh_terms: D000818:Animals; D005260:Female; D005856:Germ-Free Life; D007109:Immunity; D007074:Immunoglobulin G / Q000032:analysis; D007411:Intestinal Diseases, Parasitic / Q000276:immunology*; D008297:Male; D051379:Mice; D008809:Mice, Inbred C3H; D014235:Trichinellosis / Q000276:immunology* / Q000473:pathology
chemical_list: D007074:Immunoglobulin G