Intestinal mastocytosis and goblet cell hyperplasia in BALB/c and C3H mice infected with Neodiplostomum seoulense.

Mucosal mast cell (MMC) and goblet cell (GC) responses were observed in the small intestine of two strains of mice (BALB/c and C3H) infected with Neodiplostamum seoulense, and their roles in the host defense and worm expulsion were studied. From day 3 to 28 post-infection (PI) with 200 metacercariae, the worm recovery rate from BALB/c mice was consistently and remarkably higher than that from C3H mice. In the duodenum of both strains of mice, the main habitat of the flukes, mastocytosis was pronounced on day 7 PI but quickly diminished thereafter. Similar kinetics were observed in the jejunum and ileum, although the extent of mastocytosis was lesser in the ileum than other two areas. These MMC kinetics were not different between the two strains of mice. Moreover, the extent of mastocytosis was stronger in BALB/c mice than in C3H mice. GC hyperplasia was remarkable in the duodenum of BALB/c mice throughout the course of infection except day 14 PI, whereas it was recognizable only in the jejunum and ileum of C3H mice on day 7 PI. Mucin activation was evidently demonstrated in both strains of mice throughout the course of infection, but more marked in BALB/c than in C3H mice. The results strongly suggest that mastocytosis and GC hyperplasia are local immune responses against N. seoulense, however, they play a minor role in the host defense and worm expulsion.