Evidence of a role for intestinal CD8+ lymphocytes and macrophages in transport of Eimeria acervulina sporozoites.

The objective of this study was to identify host immune cells interacting with Eimeria sporozoites in the intestine. One-week-old SC strain chickens were infected with 2 x 10(7) sporulated Eimeria acervulina oocysts. Twenty-four hours postinfection, duodenal sections were removed, imbedded in Tissue-Tek compound, and frozen. After sectioning, tissues were stained with monoclonal antibodies to identify CD4+, CD8+, Ig+, and Bula+ lymphocytes, macrophages, and sporozoites; 28% of the sporozoites were in CD8+ cells, 28% in macrophages, and 12% in CD4+ cells. Sporozoites were not seen in Ig+ or Bula+ cells. These findings suggest that sporozoite transport most likely occurs in T lymphocytes and macrophages.