Submitted to: Conference Research Workers Disease Meeting
Publication Type: Proceedings
Publication Acceptance Date: 10/18/2003
Publication Date: 11/11/2003
Citation: Royaee, A.R., Zuckermann, F.A., Husmann, R., Calzada-Nova, G., Schnitzlein, W., Lunney, J.K. 2003. Cytokine response of porcine lymphoid cells in response to host vaccination with prrs virus. Conference Research Workers Disease Meeting P. 115.
Technical Abstract: Cytokines having the potential to regulate protective immunity against swine PRRS virus need to be identified, so that the development of anti-viral protective immunity can be positively influenced. Towards this end, we analyzed cytokine production by porcine T cells prior to and after host immunization with a modified live PRRS virus vaccine. For this purpose, blood samples were separately collected from nine pigs at week 0, 2, 5, 9, 11 and 13 following vaccination and the subsequently isolated peripheral blood mononuclear cells (PBMC) were exposed to PRRS virus for 24 hr. At this time, the relative frequency of lymphocytes expressing IFNgamma in response to the presence of PRRS virus was determined by using an ELISPOT assay. In addition, RNAs were purified from a portion of the stimulated PBMCs and utilized in quantitative real time PCR assays designed to measure the presence of transcripts encoding the immune regulatory molecules: IFNalpha' IFNgamma, IL-1alpha, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12 p35/p40, IL-15, IL-18 and IL-23. Interestingly, we observed that a period of up to 5 weeks post immunization was required for the pigs to develop a statistically significant (p<0.05) IFN-gamma protein and mRNA response to PRRS virus. Moreover, a second vaccination with PRRS virus at 7 weeks post primary immunization further increased IFN-gamma production. Whereas no apparent changes in IL-12 p35/p40 gene expression were detected, a significant up-regulation of TNF-alpha gene expression indicated the involvement of innate immunity to PRRS virus starting early after vaccination. Current experiments are aimed at determining what effect the inclusion of exogenous IFNalpha during immunization with PRRS MLV will have on cellular cytokine responses and lymphoid cell mRNA expression patterns. Our intent is to determine the importance of this cytokine in regards to regulation of the IFNalpha response and in the development of protective immunity to PRRS virus. Supported by a Biotechnology Research and Development Corporation (BRDC) grant to FZ and JKL and ARS and UIL funds.