title: Accumulation of mucosal T lymphocytes around epithelial cells after in vitro infection with Cryptosporidium parvum.
abstract: We had previously shown that ileal intraepithelial lymphocytes isolated from calves with cryptosporidiosis include significantly increased numbers of CD8+ T lymphocytes and activated CD4+ cells. These increases could result from redistribution of resident mucosal lymphocytes or from homing of peripheral T cells to ileal mucosa. To determine whether resident mucosal lymphocytes can redistribute to Cryptosporidium parvum-infected epithelium, oocysts were inoculated in vitro onto ileum explants taken from 1-2-wk-old noninfected calves. After 24 hr of incubation, the explants were collected and frozen in liquid nitrogen. Immunohistochemical analysis of T-lymphocyte subpopulations was performed on sections, and labeled lymphocytes adjacent to villous epithelial cells were counted. Compared with uninoculated explants, there was a statistically significant increase in the number of CD8+ T lymphocytes per 100 epithelial cells in oocyst-inoculated tissue. In addition, there were increased numbers of CD4+ T cells and activated (CD25+) lymphocytes adjacent to C. parvum-infected epithelium. These results show that resident mucosal T lymphocytes can accumulate at the epithelium during C. parvum infection.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Wyatt
authors.forename: E J
authors.initials: EJ
authors.lastname: Brackett
authors.forename: W J
authors.initials: WJ
authors.lastname: Barrett
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D003457:Cryptosporidiosis / Q000276:immunology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000276:immunology*; D007082:Ileum / Q000276:immunology / Q000469:parasitology; D007413:Intestinal Mucosa / Q000276:immunology* / Q000469:parasitology; D009924:Organ Culture Techniques; D013601:T-Lymphocytes