CD4 and bacterial infectious disease: The data showed that T. spiralis infection elicited higher quantities of CD4+ T-cells in the lung tissues when compared to naïve mice irrespective of bacterial infection (Fig 5B). To determine the type of the CD4+T cells, at 6 hours post bacterial infection, gene expression levels of Th1 cytokine IFN-γ, Th2 cytokines IL-4, IL-5, IL-13 and Th17 cytokine IL-17 in the lung was examined.