ABSTRACT
In order to investigate the mechanism(s) by which Epstein-Barr virus (EBV) induces the outcome of autoantibodies during infectious mononucleosis (IM), a human IgM (k) monoclonal antibody to cytoskeletal filaments of epithelial cells has been prepared by EBV transformation of peripheral blood B lymphocytes obtained from a patient with IM. The antibody was also found to react with smooth muscle of frozen sections of human stomach tissue by immunofluorescence, and with the Epstein-Barr nuclear antigen (EBNA) by an enzyme-linked immunosorbent assay. These findings demonstrate at the clonal level the epitope homology between host's cell antigens and EBV-encoded nuclear antigen, which might have relevance in EBV-induced autoimmunity.
Subject(s)
Antibodies, Monoclonal/isolation & purification , Antigens, Viral/immunology , Autoantibodies/immunology , Herpesvirus 4, Human/immunology , Infectious Mononucleosis/immunology , Antibodies, Monoclonal/immunology , Autoantigens , B-Lymphocytes/immunology , Cell Transformation, Viral , Cytoskeleton/immunology , Enzyme-Linked Immunosorbent Assay , Epithelium/immunology , Epitopes/immunology , Epstein-Barr Virus Nuclear Antigens , Fluorescent Antibody Technique , Humans , Muscle, Smooth/immunology , Tumor Cells, CulturedABSTRACT
In order to verify whether Epstein-Barr virus (EBV)-induced polyclonal B cell activation is the major cause of autoimmunity during infectious mononucleosis (IM), we have investigated, by immunoblotting, the fine specificity of anti-smooth muscle autoantibodies (autoAbs) in the sera of IM patients. Furthermore, we have isolated a number of in vivo infected EBV-positive cell lines from a patient with IM and compared the reactivity of the secreted immunoglobulins (Igs) with that of serum autoAbs. The reactivity of anti-smooth muscle autoAbs was found to be closely restricted to three proteins of approximate molecular weights 54, 52 and 48 kD. Furthermore, none of 48 EBV-positive B cell lines shared any reactivity with serum autoantibodies. Taken together, these results suggest that EBV-induced autoimmunity is not a consequence of a random activation of B cells, but a specific phenomenon, requiring mechanisms other than polyclonal B cell activation.
Subject(s)
Autoimmune Diseases/immunology , B-Lymphocytes/immunology , Herpesvirus 4, Human/immunology , Infectious Mononucleosis/immunology , Lymphocyte Activation , Antibody Specificity , Autoantibodies/analysis , Autoimmune Diseases/etiology , Cell Line, Transformed , Fluorescent Antibody Technique , Humans , Immunoblotting , Muscle, Smooth/immunologyABSTRACT
Epstein-Barr virus (EBV)-transformed B lymphocytes, either isolated from a patient with EBV-induced infectious mononucleosis or obtained by in vitro infection of B lymphocytes of donors in different clinical conditions, have been tested for the ability to endocytose particulate forms of antigens, such as human, sheep or mouse red blood cells. By light and electron microscopy, it has been found that EBV-transformed B cells are able to bind and internalize human autologous and allogeneic erythrocytes, as well as sheep and mouse erythrocytes, independent of the specificity of the secreted immunoglobulins. The ability of EBV-transformed B lymphocytes to endocytose and process particulate forms of autoantigens during infectious mononucleosis might have a role both in the production of heterophile antibodies and in EBV-induced autoimmunity.
Subject(s)
Antigens, Heterophile/immunology , B-Lymphocytes/physiology , Blood Group Antigens/immunology , Cell Transformation, Viral , Endocytosis , Erythrocytes/physiology , Animals , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/physiology , Antigen-Presenting Cells/ultrastructure , B-Lymphocytes/immunology , B-Lymphocytes/ultrastructure , Cell Line, Transformed , Erythrocytes/immunology , Erythrocytes/ultrastructure , Herpesvirus 4, Human , Humans , Infectious Mononucleosis/immunology , Infectious Mononucleosis/microbiology , Infectious Mononucleosis/pathology , Mice , SheepABSTRACT
Peripheral blood B lymphocytes from a donor with positive tuberculin skin test reaction were transformed into lymphoblastoid cell lines by Epstein-Barr virus and then fused by polyethylene glycol with mouse myeloma cells. Human-mouse hybrid cells producing human IgM monoclonal antibody to purified protein derivative of tuberculin were isolated, and the concentrated supernatant of one of these cell hybrids was tested for the capacity of interfering with DNA synthesis of human and mouse lymphocytes. The hybrid cell supernatant was found to contain soluble factors that increased DNA synthesis in unstimulated human and mouse lymphocytes and that, conversely, decreased DNA synthesis in concanavalin-A-stimulated cells. Gel filtration experiments showed that these antagonistic activities were due to at least two different factors, one of which resembled human interleukin-1 in biochemical and biological properties.
Subject(s)
B-Lymphocytes/metabolism , Cell Transformation, Viral , Herpesvirus 4, Human/immunology , Hybridomas/metabolism , Interleukin-1/biosynthesis , Lymphocyte Activation , Animals , B-Lymphocytes/analysis , B-Lymphocytes/immunology , Cell Line, Transformed , Cell Separation , Cell-Free System , Chromatography, Gel , DNA/biosynthesis , Humans , Interleukin-1/analysis , Mice , Plasmacytoma/immunology , T-Lymphocytes/metabolism , Time FactorsABSTRACT
Autoantibodies reacting with bromelain-treated autologous mouse red blood cells (Br-MRBC) are spontaneously produced by normal mice. In order to understand the biological significance of these autoantibodies, anti-Br-MRBC monoclonal autoantibodies have been prepared and studied for reactivity with a panel of frozen tissue sections from organs of normal mice by direct immunofluorescence. It has been found that the anti-Br-MRBC monoclonal autoantibodies are polyspecific, since they react with cells in multiple organs.
