Related Experiment Videos
Acquired immunity to Trichophyton mentagrophytes in thymus-grafted or peritoneal exudate cell-injected nude rats
Congenitally athymic "nude" (RNU/RNU) rats were grafted with syngeneic neonatal thymus glands and 30 days later cutaneously inoculated with Trichophyton mentagrophytes. Nude rats and thymus-grafted nude rats were susceptible to infection with T. mentagrophytes but only thymus-grafted nude rats cleared the dermatophytosis. Clearance of the fungal infection took twice as long (approximately 60 days) in thymus-grafted nude rats when compared with heterozygous euthymic (+/RNU) controls (approximately 35 days). Following clearance of the primary dermatophytosis, peritoneal exudate cells (PEC) were adoptively transferred from either thymus-grafted or heterozygous rats to nude rats. Eight of 12 PEC-recipient nude rats acquired the capacity to resolve T. mentagrophytes-induced dermatophytosis (mean clearance time was approximately 40 days). All heterozygous (+/RNU) rats, thymus-grafted nude rats (4/4), and 8 of 12 PEC-recipient nude rats, which had cleared a primary dermatophytosis also expressed delayed-type hypersensitivity and elevated serum antibody titers to trichophytin antigen. These results demonstrate that immunity to T. mentagrophytes can be acquired in congenitally athymic nude rats following thymus grafting or injection of PEC from syngeneic +/RNU rats; however, injection of PEC from trichophytin-sensitized +/RNU donor rats to nude recipient rats did not result in transfer of specific adoptive immunity to T. mentagrophytes. Interestingly, PEC transfer from non-sensitized +/RNU rats was comparable to thymus grafting in effecting clearance of T. mentagrophytes dermatophytosis. These results suggest that acquired immunity to T. mentagrophytes in the rat is T cell-dependent, and that the absence of functional T lymphocytes and not an epithelial defect results in chronic dermatophytosis in the nude rat.
Congenitally athymic "nude" (RNU/RNU) rats were grafted with syngeneic neonatal thymus glands and 30 days later cutaneously inoculated with Trichophyton mentagrophytes. Nude rats and thymus-grafted nude rats were susceptible to infection with T. mentagrophytes but only thymus-grafted nude rats cleared the dermatophytosis. Clearance of the fungal infection took twice as long (approximately 60 days) in thymus-grafted nude rats when compared with heterozygous euthymic (+/RNU) controls (approximately 35 days). Following clearance of the primary dermatophytosis, peritoneal exudate cells (PEC) were adoptively transferred from either thymus-grafted or heterozygous rats to nude rats. Eight of 12 PEC-recipient nude rats acquired the capacity to resolve T. mentagrophytes-induced dermatophytosis (mean clearance time was approximately 40 days). All heterozygous (+/RNU) rats, thymus-grafted nude rats (4/4), and 8 of 12 PEC-recipient nude rats, which had cleared a primary dermatophytosis also expressed delayed-type hypersensitivity and elevated serum antibody titers to trichophytin antigen. These results demonstrate that immunity to T. mentagrophytes can be acquired in congenitally athymic nude rats following thymus grafting or injection of PEC from syngeneic +/RNU rats; however, injection of PEC from trichophytin-sensitized +/RNU donor rats to nude recipient rats did not result in transfer of specific adoptive immunity to T. mentagrophytes. Interestingly, PEC transfer from non-sensitized +/RNU rats was comparable to thymus grafting in effecting clearance of T. mentagrophytes dermatophytosis. These results suggest that acquired immunity to T. mentagrophytes in the rat is T cell-dependent, and that the absence of functional T lymphocytes and not an epithelial defect results in chronic dermatophytosis in the nude rat.