Corynebacterium pyruviciproducens promotes the production of ovalbumin specific antibody via stimulating dendritic cell differentiation and up-regulating Th2 biased immune response.

Corynebacterium pyruviciproducens (C. pyruviciproducens), a newly discovered Corynebacterium, is gram-positive, non-flagellate, non-spore-forming lipophilic rod. No known pathogenic components of Corynebacteria have been found in this new bacterium, such as diphtheria toxin and tuberculostearic acid. In the present study, referring to Propionibacterium acnes (P. acnes), a well-known bacterial adjuvant, the stimulation of dendritic cells by C. pyruviciproducens was analyzed through detecting the levels of cytokine-secretion, ability of cell-proliferation and expression of membrane molecules. In addition, the effect of C. pyruviciproducens in promoting antibody production in vivo was detected. Compared with P. acnes, C. pyruviciproducens more strongly enhanced cytokine secretion including inflammatory factor IL-6 and Th1-associated molecule IL-12, and more effectively induced proliferation, activation or maturation of D2SC/1 (a murine dendritic cell line) and bone marrow-derived dendritic cells (BMDC). Vaccination studies in mice using ovalbumin (OVA) as a model antigen showed that C. pyruviciproducens effectively promoted antigen-specific humoral immune response by increasing OVA-specific antibody, Th2-biased response in spleen and high IL-4/IFN-γ ratio in serum.