Phenotypic profile of intraepithelial lymphocytes in the non-neonatal pig model for cryptosporidiosis

The purpose of this study was to quantitate the subpopulations of intraepithelial lymphocytes (IEL) in the ileum of normal and immunosuppressed non-neonatal pigs infected with Cryptosporidium parvum. This was accomplished by using flow cytometry. Pigs from the litters of four sows were assigned to one normal control, one inoculation control, and four experimental groups. Experimental pigs were immunosuppressed with FK-506 (Tacrolimus® ). Infected pigs received 106 oocysts of C. parvum orogastrically. Intraepithelial lymphocytes were isolated, differentially enumerated, and analyzed by flow cytometry using antibodies against CD3, CD4, CD8, CD25, and IgM lymphocyte markers. The intraepithelial lymphocyte profiles in normal control and immunosuppressed non-neonatal pigs inoculated with C. parvum were not significantly (P > 0.05) different. Also, FK-506 did not significantly (P > 0.05) reduce the number of intraepithelial lymphocytes expressing CD3, CD4, CD8, CD25, and IgM markers and, thus, does not explain the chronic, cryptosporidial infections observed in the immunosuppressed, infected pigs.