Increases in cytokine and antimicrobial peptide gene expression in horses by immunomodulation with Propionibacterium...

Immunomodulation with Propionibacterium acnes is used for prophylaxis of respiratory disease or in horses suffering from chronic pulmonary inflammation; however, the mechanism for this response is poorly understood. Semiquantitative reverse transcriptase-polymerase chain reaction assays were used to evaluate gene expression of interleukin (IL)-2, IL-10, interferon (IFN)-gamma, and NK-lysin in healthy horses treated with P. acnes. Findings in the study indicated that horses treated with a P. acnes-based immunomodulator exhibited increased IFN-gamma and NK-lysin gene expression in peripheral blood mononuclear cells. These results suggest that part of the immunostimulating properties of a P. acnes-based immunomodulator is derived from enhanced gene expression of the type-1 cytokine IFN-gamma and NK-lysin, an antimicrobial peptide.