Peptide concentration regulates priming of naive T cells to develop into Th1/Tc1 or Th2/Tc2 cells

Abstract

Objective To study the effect of concentration of TCR-specific antigen peptides on priming naive CD4~+ T cells to develop into Th1/Th2 cells or naive CD8~+ T cells to develop into Tc1/Tc2 cells. Methods TCR-specific peptides with series of concentration were co-cultured with routine spleen DCs to activate murine naive CD4~+/CD8~+ T cells. The production of intracellular cytokines IFN-γand IL-4 were measured by flow cytometry. The dividing profile of activated T cells was analyzed by CFSE staining. Results Lower concentration of specific peptides favored Th2/Tc2 polarization while higher concentration benefited Th1/Tc1 polarization. The influence of peptides concentration on Th cells differentiation is higher than that on Tc cells. Conclusion Antigen peptides can stimulate activation of naive T cells in a wide range of concentration. However, with the increase of peptides concentration, activated T cells differentiated grad-ually from Th2/Tc2 to Th1/Tc1, which will provide significant value to control immunized dose of vaccine candidates in animal experiments. Key words: Antigen peptide; Naive CD4~+/CD8~+ T cell; Dentritic cell; Differentiation