A synthetic triacylated pseudo-dipeptide molecule promotes Th1/TReg immune responses and enhances tolerance induction via the sublingual route.

In this study, we tested two triacylated pseudo-dipeptidic molecules, OM-197-MP-AC and OM-294-BA-MP as candidate adjuvants for allergy vaccines. Both molecules induce human dendritic cell (h-DC) maturation and polarize naïve T cells toward the Th1 type with IFNgamma production. Only OM-294-BA-MP induces IL10 gene expression both in monocyte-derived DCs and CD4+ naïve T cells. Sublingual administration of OM-294-BA-MP plus the antigen enhances tolerance induction in BALB/c mice with established asthma to ovalbumin with an impact on both airways hyperresponsiveness and lung inflammation. Given its Th1/Treg polarizing properties, OM-294-BA-MP is a valid candidate for sublingual allergy vaccines.