Experimental obeliscoidosis in rabbits. II. Immunohistological changes in the stomach and some aspects of immune response

The dynamics of IgA- and IgG-containing cells in the stomach mucosa of rabbits infected with Obeliscoides cuniculi was studied by means of a direct immunofluorescence method. An increase in the numbers of IgA-containing cells was found during the histotrophic phase of infection. An aggregation of secretory IgA on the external surface of the cuticle of worms was also observed. There was no stimulation of proliferation of local IgG-containing cells. The numbers of IgG-containing cells in infected rabbits were very low, and also very few IgG-containing cells were found in the stomach mucosa of uninfected rabbits. A weak immunological response in the blood sera, was observed only in a few animals after infection with various doses of larvae. No difference was found in the level of antibody titers as a result of exposure of animals to various doses of larvae. A significant increase in the number of IgA-containing cells in the stomach of infected rabbits might imply that О. cuniculi stimulated a local immune response of parasitized rabbits.