Effect of TLR2 coactivation on Naïve CD4+ T cells differentiation and function

We have recently demonstrated that mycobacterial ligands engage Toll like receptor 2 (TLR2) on CD4+ T cells and up-regulate T-cell receptor (TCR) triggered- Th1 responses in vitro and in vivo. To extend our previous studies on the role of TLR2 in the regulation of T-cell function and differentiation, we compared the gene expression profile of mouse CD4+ T cells co-stimulated via CD28 or TLR2. Unlike CD28 co-stimulation, TLR2 co-engagement with CD3 triggered the regulation of a very discrete set of genes. Unexpectedly, naïve CD4+ T- cells co-stimulated via TLR2 showed a significant up-regulation of Il9 mRNA compared to cells co-stimulated via CD28. Mouse CD4+ T cells were co-stimulated via CD28 or TLR2 in addition to CD3 at two different timepoints i.e. 24hrs and 48 hrs. Total RNA were extracted from each treatment conditons and used for hybridization on Affymetrix microarrays.