DNA vaccination breaks tolerance for a neo-self antigen in liver: a transgenic murine model of autoimmune hepatitis.
Understanding the pathogenesis of autoimmune hepatitis requires an animal model in which chronic progressive immune injury develops spontaneously or with minimal manipulations. The new transgenic mouse model proposed in this study is based on the hypothesis that infectious agents have the potential to initiate autoreactivity through molecular mimicry. A transgenic mouse expressing lymphocytic choriomeningitis virus nucleoprotein (NP) in a H-2(b) background developed liver injury when vaccinated with plasmids expressing NP as an intracellular or a secretory protein. Coinjection of plasmids coding for NP and IL-12 facilitated the induction of a Th1 phenotype as detected by a specific B lymphocyte response characterized by a predominance of IgG2 subclass anti-NP Abs. CTLs activated in peripheral lymphoid organs by DNA vaccination migrated to the periportal and lobular areas of the liver. Their presence was associated with a significant degree of cytolysis, as evidenced by elevated transaminases several weeks after immunization. As activated specific T lymphocytes proliferated in the periphery and caused cytolysis of target cells, this study suggests that autoimmune hepatitis can be triggered by molecular mimicry, and that local injury may not be essential to initiate autoreactivity in the liver.
Djilali-Saiah
Idriss
I
Service de Gastroentérologie, Departement de Pédiatrie, Hôpital Sainte-Justine, Montréal, Québec, Canada.
Lapierre
Pascal
P
Vittozi
Susana
S
Alvarez
Fernando
F
D000818:Animals; D001324:Autoantigens / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D003587:Cytomegalovirus / Q000235:genetics / Q000276:immunology; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D004195:Disease Models, Animal; D005822:Genetic Vectors / Q000008:administration & dosage / Q000138:chemical synthesis / Q000276:immunology; D019693:Hepatitis, Autoimmune / Q000235:genetics* / Q000276:immunology* / Q000473:pathology; D006801:Humans; D016056:Immunodominant Epitopes / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D007273:Injections, Intramuscular; D008099:Liver / Q000276:immunology* / Q000821:virology; D008217:Lymphocytic choriomeningitis virus / Q000235:genetics / Q000276:immunology; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009698:Nucleoproteins / Q000235:genetics / Q000276:immunology; D011228:Prealbumin / Q000235:genetics / Q000276:immunology; D017634:Self Tolerance / Q000235:genetics; D013539:Simian virus 40 / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000821:virology; D014407:Tumor Cells, Cultured; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014761:Viral Hepatitis Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
D001324:Autoantigens; D016056:Immunodominant Epitopes; D007074:Immunoglobulin G; D009698:Nucleoproteins; D011228:Prealbumin; D019444:Vaccines, DNA; D014761:Viral Hepatitis Vaccines