title: The athymic nude rat. IV. Immunocytochemical study to detect T-cells, and immunological and histopathological reactions against Trichinella spiralis.
abstract: The anti-parasite response was investigated after oral infection of athymic nude (rnu/rnu) rats and heterozygous (+/rnu) littermates with 1000 muscle larvae of Trichinella 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 of +/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. These data support earlier studies that the nude rat lacks functional T cells. As the counts of connective tissue mast cells (CTMC), intestinal mast cells (IMC) and globule leucocytes (GL) in small intestine of uninfected rnu/rnu rats were equal or higher than in +/rnu rats, it is concluded that the origin of these cells is thymus-independent. In contrast to +/rnu rats, infection of rnu/rnu rats induced no increase of CTMC, IMC or GL. Thus, these cells depend on T cells to undergo proliferation. Finally, results of this study were inconclusive whether IMC are precursors for GL, or that they represent independent cell populations.
mesh_terms: D000818:Animals; D002455:Cell Division; D007136:Immunoglobulins / Q000032:analysis; D007421:Intestine, Small / Q000469:parasitology; D007962:Leukocytes / Q000276:immunology*; D008198:Lymph Nodes / Q000166:cytology; D008407:Mast Cells / Q000276:immunology*; D009132:Muscles / Q000469:parasitology; D010581:Peyer's Patches / Q000166:cytology; D051381:Rats; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology*; D014059:Tongue / Q000469:parasitology; D014234:Trichinella / Q000276:immunology; D014235:Trichinellosis / Q000276:immunology* / Q000469:parasitology
chemical_list: D007136:Immunoglobulins