Analysis of the immunomodulatory properties of mycobacterium cell wall fraction on the cytokine production of peripheral blood mononuclear cells of healthy dogs

Background Mycobacterium cell wall fraction (MCWF) is derived from nonpathogenic Mycobacterium phlei and is used as an immunomodulatory compound in clinical practice, yet its mode‐of‐action requires further research. Objective To evaluate the host response to MCWF in canine peripheral blood mononuclear cells (PBMCs) by using enzyme‐linked immunosorbent assays (ELISA) and quantitative reverse transcription (qRT)‐PCR for assessment of cytokines. Animals Eight healthy Labrador retrievers. Materials and Methods PBMCs were isolated from whole blood using density centrifugation. The cells were cultured with different concentrations of MCWF or a potent stimulator of cytokine production, phorbol 12‐myristate 13‐acetate/ionomycin, or left in cell culture medium for 24, 48 and 72 h. Cytokines were measured by ELISA for interleukin (IL)‐4, IL‐10 and interferon‐gamma (IFN‐γ), and by qRT‐PCR for IL‐4, IL‐10, IL‐13, IFN‐γ, tumour necrosis factor alpha (TNF‐α) and transforming growth factor‐beta. Results A significant increase of IL‐10 messenger ribonucleic acid (mRNA) was detected at all time points for all concentrations of MCWF (p