Coccidiosis: localization of lymphoblasts in the infected small intestine.

Peripheral blood lymphocytes of chickens and thoracic duct lymphocytes and mesenteric lymph node cells of rats, were labelled with 125I-deoxyuridine and injected intravenously into chickens or rats respectively. Sixteen to 18 h later the intestines of coccidia infected animals contained more radioactivity than those of uninfected controls. This result was obtained with cell suspensions from both infected and normal donors indicating that, as with nematode infected rodents, the increased homing of the cells to parasitised gut was not antigen specific. In chickens the stimulus which causes the increased homing of cells to the intestine was induced within hours of parasite inoculation. This reflects the rapid response of this host, previously described with other parameters, and which may be characteristic of birds.