RESUMEN
Macrophages play an important role in both the innate and adaptive immune responses. These include phagocytosis, killing of microorganisms, antigen presentation, and induction of immune cytokines and antimicrobial genes. Macrophage activity is reported to be controlled by diverse exogenous antigenic or endogenous metabolic molecules, and the underlying mechanisms are well documented in human and mouse macrophage cells. Bacterial lipopolysaccharide (LPS) is known to be one of the most potent stimuli activating macrophages through the toll like receptor 4 (TLR4) signaling pathway. There are other antigenic molecules, such as muramyl dipeptide (MDP) and outer membrane protein A (OmpA), that are also known to activate immune cells. On the other hand, short chain fatty acids (SCFAs) such as acetate and butyrate are produced by gut microbiota and control host energy metabolism and signal transduction through GPR receptors. However, there are few studies demonstrating the effects of these molecules in macrophages from domestic animals, including domestic pigs. In this study, we attempted to characterize gene expression regulation in porcine macrophages (PoM2, Pig Monocytes clone 2) following treatment with LPS, MDP, OmpA, and two short chain fatty acids using porcine genome microarray and RT-PCR techniques. A number of novel porcine genes, including anti-microbial peptides and others, appeared to be regulated at the transcriptional level. Our study reports novel biomarkers such as SLC37A2, TMEN184C, and LEAP2 that are involved in the porcine immune response to bacterial antigen LPS and two short chain fatty acids.