Cytokine gene expression in CD4+ and CD8+ T cell subsets of chickens infected with Marek's disease virus

This thesis is an investigation of host responses to Marek's disease virus (MDV) in chickens. In order to study T cell-mediated responses, CD4+ and CD8+ T cells were isolated from spleens of specific pathogen free (SPF) as well as genetically-defined B19 /B19 (susceptible) and B21/B 21 (resistant) chickens at 4, 10, and 21 days post-infection (d.p.i.) with MDV. The expression of cytokine genes, including IFN-gamma, IL-6, IL-18, IL-4, and IL-10 as well as viral genes, meq and glycoprotein B (gB), was quantified by quantitative real-time reverse transcription-PCR (qRT-PCR). MDV infection elicited an up-regulation in the expression of IL-18 in SPF chickens and IL-10 in genetically-defined chickens in both CD4+ and CD8 + T cell subsets. Despite the elicitation of cytokine responses, a correlation between cytokine gene expression in T cell subsets and genetic resistance versus susceptibility to MD could not be established in this study.