title: Studies of innate immune systems against human cells.
abstract: Pigs are frequently used as animal models for experiments in the surgical field, including allo- and xeno-transplantation. Regeneration studies, including studies dealing with human- and monkey-induced pluripotent stem cells (iPSC), have gradually progressed, with pigs sometimes being used as the scaffold. However, the immunological response of pigs against humans, especially innate immunities, remain unclear. This study reports on a comprehensive study of pig innate immunity against humans.
  
  
  
  Hemolytic complement activity of pig serum was measured using a microtitration technique. The pig natural anti-human antibody (Ab) was examined using human peripheral blood mononuclear cells (PBMC). The reaction of pig natural killer (NK) cells and monocytes/macrophages against human cells was also assessed.
  
  
  
  Most of the pig complement titers were measured based on methods used in human complement assays. The alternative pathway for pig complement reacts with human cells, indicating that pig complement can react with human cells. Pig serum contains relatively high levels of natural antibodies, IgM and IgG, to human PBMC. Furthermore, the killing of NK cells- and monocyte/macrophage-mediated human cells was clearly confirmed.
  
  
  
  The collective findings indicate that the pig innate immunological systems, not only serum but also cellular factors, are able to recognize and injure human cells.
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Rieko
authors.initials: R
authors.lastname: Sakai
authors.affiliation: Department of Medical Technology, Faculty of Health Sciences, Kobe Tokiwa University, Kobe, Japan.
authors.forename: Etsuko
authors.initials: E
authors.lastname: Kitano
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Maeda
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Pei-Chi
authors.initials: PC
authors.lastname: Lo
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Eguchi
authors.affiliation: Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Life Sciences, School of Agriculture, Meiji University, Kawasaki, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nagashima
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Hiroomi
authors.initials: H
authors.lastname: Okuyama
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan. Electronic address: miyagawa@orgtrp.med.osaka-u.ac.jp.
authors.forename: Shuji
authors.initials: S
authors.lastname: Miyagawa
mesh_terms: D000818:Animals; D000910:Antibodies, Heterophile / Q000097:blood*; D015478:Antigens, Heterophile / Q000276:immunology*; D002478:Cells, Cultured; D003165:Complement System Proteins / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007113:Immunity, Innate; D007694:Killer Cells, Natural / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D023421:Models, Animal; D009000:Monocytes / Q000276:immunology*; D044968:Regenerative Medicine; D013552:Swine / Q000276:immunology*; D014183:Transplantation, Heterologous
chemical_list: D000910:Antibodies, Heterophile; D015478:Antigens, Heterophile; D003165:Complement System Proteins
keywords: Complement; Innate immune systems; Macrophage; NK