Lactobacillus delbrueckii as a potential skin adjuvant for induction of type 1 immune responses

We evaluated the ability of Lactobacillus delbrueckii UFV H2b20, a probiotic candidate, to stimulate the production of inflammatory cytokines and to induce macrophage activation and Th1 differentiation in peripheral blood mononuclear cells ( PBMC) from healthy volunteers. Our results show that PBMC stimulated with heat- killed Lact. delbrueckii produced elevated levels of IL- 12, IFN-. and TNF-alpha but no IL-10. IFN-gamma production was IL- 12 dependent with NK cells as the main source. Furthermore, PBMC infected with Leishmania amazonensis presented elevated microbicidal activity when co-incubated with Lact. delbrueckii. Finally, Lact. delbrueckii was capable of inducing in vitro differentiation of L. amazonensis- specific Th1 cells. These findings suggest that this probiotic may be used as an adjuvant in vaccination protocols.