The athymic nude rat. IV. Immunocytochemical study to detect T‐cells, and immunological and histopathological reactions against Trichinella spiralis

Publisher Website
Google Scholar
Abstract
The antiparasite response was investigated after oral infection of athymic nude (rnu/rnu) rats and heterozygous (+/rnu) littermates with 1000 muscle larvae of T. spiralis. No IgM, IgG and IgE antibodies were detected in serum of rnu/rnu rats. Expulsion of adult worms from the small intestine was prolonged (worms were nearly all expelled at days 14 and 91 in +/rnu and rnu/rnu rats, respectively). The yield of muscle larvae in the carcasses of nude rats at day 91 was 33 times higher than in +/rnu rats. In contrast to the strong inflammatory reaction in the parasitized tongue +/rnu rats, no infiltration was observed in rnu/rnu rats. Using an immunoperoxide method with monoclonal anti-rat T-cell antibody, no T cells were identified in spleen, mesenteric lymph node and Peyer''s patches. Apparently, the nude rat lacks functional T cells. As the counts of connective tissue mast cells (CTMC), intestinal mast cells (IMC) and globule leukocytes (GL) in small intestine of uninfected rnu/rnu rats were equal or higher than in +/rnu rats, the origin of these cells may be thymus-independent. In contrast to +/rnu rats, infection of rnu/rnu rats induced no increase of CTMC, IMC or GL. These cells depend on T cells to undergo proliferation. It was inconclusive whether IMC are precursors for GL, or if they represent independent cell populations.