Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: January 2, 1997
Publication Date: N/A
Technical Abstract: Ostertagia ostertagi (Oo) causes major economic losses in cattle production, in large part because of the extended time required for the development of functional protective immunity. The mucosal immune system represents the first line of immunological defence, therefore, characterization of mucosal immune response is important for the understanding of the basis of the delay in the acquisition of a protective immune response against this parasite. Cell surface phenotype of lamina propria lymphocytes from non-infected (control animals) and animals after a primary non-protective primary infection with Oo was analyzed by indirect immunofluorescence staining. Potential functional activity of the cells was determined by quantification of mRNA levels of several T cell cytokines (IL-2, IL-4, IL-10 and IFN-g) which was performed by competitive reverse transcriptase polymerase chain reaction (competitive RT-PCR). Phenotypic analysis showed a increase in the percentage of gamma delta-T cells (WC1+), B cells (IgM+) and activated cells (IL-2R+) 10 days after infection, however, within 2 months, cell staining characteristics were comparable to preinfection levels. Cytokine analysis showed elevated levels of IL-4 and IFN-g in infected animals compared to control animals at 10 days and 60 days after infection. An increase in IL-10 mRNA levels was not observed until 60 days after infection. These studies provide information on the changes and mechanisms by which animals may become immune to gastric parasites.