An CLA-fed porcine model was tested for cellular immunity in vivo by vaccination and/or infection challenge, CD4+ and CD8+ T cells isolated from virally infected pigs were studied for IFN-γ production on ex vivo re-stimulation: CLA was found to suppressed IFN-γ production in CD4+ but not in CD8+ T cells in these experiments [5-8]. Here, CD4 is linked to infection.