Characterization of effector cells in lymphocytotoxicity to autologous hepatocytes in HBsAg-positive and autoimmune chronic active hepatitis (CAH).
Peripheral blood lymphocyte subsets involved in cytotoxicity to autologous hepatocytes have been characterized by isolation on antibody-coated Petri dishes in autoimmune and HBsAg-positive chronic active hepatitis (CAH). In autoimmune CAH and in HBsAg-positive CAH without HBcAg in liver tissue, cytotoxicity is sustained by non-T lymphocytes and is confined to M1-positive cells bearing Fc receptors: M1 cytotoxicity inhibition by adding aggregated IgG suggests that these cells are responsible for an antibody-dependent cell-mediated mechanism (ADCC). Moreover, when T-enriched fractions were separated in T4, T8 and 5/9 positive subsets, only the first one showed a significant cytotoxicity: T4 positive cells might act as cytotoxic T cells or might be involved in delayed type hypersensitivity (DTH) reactions. Cytotoxic T lymphocytes in HBsAg-positive CAH with HBcAg in liver tissue are confined in T8 positive subset, while helper/inducer T cells (T4 positive or 5/9 positive) seem to play an important role only in the induction of cell-mediated injury against hepatocytes. The inhibition of T cell-cytotoxicity by preincubating liver cells with monoclonal antibody (Mab) anti-HLA AB and not with Mab anti-HLA DR or aggregated IgG supports the involvement of the class I major histocompatibility complex (MHC) expressed on the hepatocyte surface.
D000911:Antibodies, Monoclonal / Q000276:immunology; D001327:Autoimmune Diseases / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D005260:Female; D006680:HLA Antigens / Q000276:immunology; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D006509:Hepatitis B / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006521:Hepatitis, Chronic / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000276:immunology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D008099:Liver / Q000276:immunology / Q000473:pathology; D011961:Receptors, Fc / Q000276:immunology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000911:Antibodies, Monoclonal; D006680:HLA Antigens; D015234:HLA-A Antigens; D015235:HLA-B Antigens; D006684:HLA-DR Antigens; D006514:Hepatitis B Surface Antigens; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G; D011961:Receptors, Fc; C044411:polymeric IgG