LOCAL ILEAL CYTOKINE RESPONSES IN CATTLE DURING A PRIMARY INFECTION WITH CRYPTOSPORIDIUM-PARVUM

In the present study, localized changes in cytokine transcription prof iles were examined in neonatal calves following a primary infection wi th Cryptosporidium parvum, using competitive reverse transcriptase pol ymerase chain reaction (RT-PCR). Total RNA was prepared from ileocecal lymph nodes (LN), lamina propria lymphocytes (LPL), and intraepitheli al lymphocytes (IEL) isolated from neonatal calves 7 days after C. par vum infection. Competitive RT-PCR performed on cDNA samples containing internal cytokine gene competitor molecules showed increases in the l evels of interferon-gamma and interleukin-12 (IL-12) (P40) mRNA in bot h LPL and IEL populations but not in the draining LN. In addition, the levels of mRNA of the newly identified growth factor IL-15 decreased in the IEL of the infected animals. No consistent differences were see n in any of the cell populations when the samples were analyzed for IL -10 and levels of mRNA for IL-2 and IL-4 were low and highly variable in both infected and control groups in all 3 lymphocyte populations.