Modulation of cytokine production profiles in splenic dendritic cells obtained from SAG 1 transgenic mice infected with Toxoplasma gondii.
We examined the role of splenic dendritic cells in immune response to Toxoplasma gondii infection in SAG1 (P30+) transgenic mice by investigating the kinetics of intracellular cytokines expression of IL-4, IL-10, IL-12 and IFN-γ by intracellular cytokine staining (ICS) using flow cytometry, and compared the results to those of their P30- littermates. The cytokines, IL-10 and IL-4 were expressed at higher levels compared to Th1 cytokines IL-12 and IFN-γ with IL-10 showing the highest expression in both groups of mice. Moreover, peak cytokine levels in P30+ mice were on day 5 post-infection and on day 7 post-infection in P30- mice. 30% of the P30+ mice succumbed to infection by day 7 post-infection whereas all the P30- littermates survived. The co-stimulatory molecule, CD80 and MHC phycoprotein, were up-regulated both in P30+ mice and their P30- littermates following T. gondii infection. Our results suggest that the immune response to T. gondii infection demonstrates a concomitant Th1 and Th2 cytokine intracellular and mRNA expression with a crucial role for IL 10/IL 4 in the resolution of infection.
Key words: Dendritic cells, intracellular cytokines, Toxoplasma gondii, SAG1 transgenic mice.