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.

Introduction
 Materials and Methods
  Cell Culture and Reagents
  DNA Microarray
  Reversre Transcriptase (RT) PCR
 Results
  Analysis of Differentially Expressed Porcine Genes
  Gene Expression Analysis of Porcine Genes identified in DNA microarray by RT-PCR
  Expression Profile of Porcine Antimicrobial Genes
 Discussion
 Acknowledgements
 ORCID
 References

• Na-Eun Han(Division of Biochemistry, College of Medicine, Chungbuk National University)
• Eun-Joo Lee(Division of Biochemistry, College of Medicine, Chungbuk National University)
• Kwan-Sik Park(Division of Biochemistry, College of Medicine, Chungbuk National University)
• In-Sook Jeon(Division of Biochemistry, College of Medicine, Chungbuk National University)
• Hak-Kyo Lee(Department of Animal Biotechnology, Chonbuk National University)
• Ki-Duk Song(Department of Animal Biotechnology, Chonbuk National University)
• Joong-Kook Choi(Division of Biochemistry, College of Medicine, Chungbuk National University) Corresponding author