Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Proceedings
Publication Acceptance Date: March 20, 1996
Publication Date: N/A
Technical Abstract: Analysis of the cytokine pattern induced in cattle infected with the gastrointestinal parasite, Ostertagia ostertagi, is necessary for understanding the basis of the delay in the acquisition of protective immune responses. We used 2 recently developed assays to quantify mRNA levels of several T cell cytokines; an RNase Protection Assay (RPA) and a Competitive reverse transcriptase- polymerase chain reaction assay (RT-PCR) on abomasal lymph node populations (ABLN) after a non-protective primary infection. The results of analyses on polyclonal activated populations showed a "Th2-like" response with a reduction in IL-2 and IFN-gamma mRNA. Correspondingly, analysis of non-stimulated ABLN showed a decrease in IL-2 and an increase in IL-4 and IL-10 transcripts; however the level of message of the Th1 cytokine IFN-gamma was also substantially increased following infection. These changes were accompanied by changes in the cell surface phenotype of the ABLN corresponding to a "Th2" response; reduced percentage of CD3+, and an elevation in the number of IgM+. In addition, a significant rise in the number of gamma-delta-T-cells in the lymph nodes was also found and may account for the elevated amounts of IFN-gamma in the non-stimulated cell populations.