There is no sufficient porcine specific antibody available to investigate the ontogeny and development of porcine pulmonary alveolar macrophage (PAM). Therefore, several mouse anti-porcine macrophage mAbs have been produced and characterized in this study. First, the monoclonal antibody PM18-7, an IgG1, kappa isotype, bound to 91% of PAM, 6% of monocytes, and 2% of granulocytes indicating PM 18-7 was found to be PAM specific. Monocyte derived macrophages could not be induced to express the PM18-7 antigen by culture. PM18-7 was immunoprecipitated with a molecule of 260 kDa under non-reducing conditions and with that of 130 kDa under reducing conditions in SDS-PAGE. Second, the monoclonal antibody PM3-15, an IgG1, kappa isotype, bound to 92% of PAM, 86% of monocytes, and 3% of granulocytes indicating PM3-15 was mononuclear phagocyte specific. PM3-15 was immunoprecipitated with a molecule of 245 kDa under non-reducing conditions and those of 150, 95 kDa under reducing conditions in SDS-PAGE. Third, the monoclonal antibody PM16-6, an IgM isotype, bound to 82% of PAM, 89% of monocytes, and 82% of granulocytes indicating PM16-6 recognizes those cells of myeloid lineage such as macrophages, monocytes and granulocyte. The antigen immunoprecipitated by PM16-6 was 120 kDa under non-reducing conditions and was 75, 25 kDa under reducing conditions. Finally, the antigen bound to PM18-7 was identified as ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1, CD203a), PM3-15 was figured out as integrin alpha M beta 2 precursor (ITGaM, CD11b) and PM16-6 was identified as Thimet oligopeptidase (THOP-1) by the LC-MS/MS protein sequencing method. (C) 2015 Elsevier Inc. All rights reserved.