Pidotimod is a synthetic dipeptide with immunomodulatory properties on both innate and adaptive immune responses in in vitro studies. It has been shown to induce dendritic cell (DC) maturation, to upregulate the expression of HLA-DR and co-stimulatory molecules CD83 and CD86, to stimulate the release of pro-inflammatory molecules from DCs, which drives T cell proliferation and differentiation towards a Th1 phenotype, to enhance natural killer cell functions, to inhibit thymocyte apoptosis, and to promote phagocytosis. Through separate effects on ERK1/2 and NF-κB, pidotimod was shown to increase the expression of toll-like receptor 2 proteins. Pimotimod does not affect expression of ICAM-1 or the release of IL-8.
