Innate immunity and primary biliary cirrhosis.
There has been a rapid growth in our understanding of the molecular bases of primary biliary cirrhosis (PBC). These efforts were initiated when the immunodominant mitochondrial autoantigen was cloned and sequenced. Using the recombinant cloned antigen as a tool, research has focused on the effector mechanisms of disease and the uniqueness of the primary target tissue, the intrahepatic bile ducts. Most recently, there have been experimental data suggesting that innate immunity changes may be critical to the initiation and perpetuation of the autoimmune injury, as in the case of the enhanced response of monocytes and memory B cells to infectious stimulation and environmental mimics. These observations are important as they help fill in the many gaps which remain on the most difficult subject of autoimmunity, etiology. Indeed, based on the available data, several experimental models of PBC have been developed. These models illustrate and suggest that PBC can be initiated by several mechanisms, all of which lead to loss of tolerance to the mitochondrial antigens. However, once this adaptive response develops, it appears that much of the subsequent pathology is exacerbated by innate responses. We suggest that future therapeutic efforts in PBC will depend heavily on understanding the nature of this innate immune responses and methodology to blunt their cytotoxicity.
Selmi
Carlo
C
Department of Internal Medicine, IRCCS Istituto Clinico Humanitas, University of Milan, and Division of Internal Medicine and Liver Unit, San Paolo Hospital School of Medicine, Milan, Italy.
Lleo
Ana
A
Pasini
Simone
S
Zuin
Massimo
M
Gershwin
M Eric
ME
D000818:Animals; D001323:Autoantibodies / Q000276:immunology; D001324:Autoantigens / Q000276:immunology; D015551:Autoimmunity / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D001653:Bile Ducts, Intrahepatic / Q000166:cytology / Q000276:immunology; D015745:Granuloma, Foreign-Body / Q000276:immunology; D006801:Humans; D007113:Immunity, Innate; D007075:Immunoglobulin M / Q000096:biosynthesis; D008099:Liver / Q000276:immunology; D008105:Liver Cirrhosis, Biliary / Q000209:etiology* / Q000276:immunology*; D024101:Mitochondrial Proteins / Q000276:immunology; D018716:Molecular Mimicry / Q000276:immunology; D009000:Monocytes / Q000276:immunology; D055611:Natural Killer T-Cells / Q000276:immunology
D001323:Autoantibodies; D001324:Autoantigens; D007075:Immunoglobulin M; D024101:Mitochondrial Proteins