bromochloroacetic-acid and Infectious-Mononucleosis

The present study was undertaken to unequivocally demonstrate the morphology, immunophenotype, and localization of Epstein Barr virus (EBV)-infected cells as well as the type of infection (latent versus productive) in tonsils of acute infectious mononucleosis. Paraffin sections from nine cases with clinical, serologic, and morphologic evidence of EBV infection were analyzed for the detection of small transcripts, designated EBER1 & 2, and BHLF1 by in situ hybridization (ISH) using nonisotopically labeled probes. ISH was combined with immunohistology, employing a broad panel of antibodies against B-, T-, epithelial-, macrophage-, and follicular dendritic cell (FDC)-antigens. All EBER-positive cells could be identified as lymphocytes, as they did not exhibit any morphologic or immunologic characteristics of epithelial cells, macrophages, or FDCs. A preferential accumulation of EBER-positive cells was noted around crypts, within surface squamous epithelium, and in the surroundings of necrosis. The majority of these lymphocytes could be shown to be B cells, which morphologically included Reed-Sternberg (RS)-like cells, immunoblasts, medium-sized lymphoid cells, as well as cells with plasmacytoid differentiation. In all cases, a varying number of EBER-positive T cells could be identified. ISH for BHLF1-RNA detection showed that almost all cases contained single positive small lymphoid cells, indicating a transition from latent to productive infection cycle. Such cells could also be detected within the crypt epithelium reaching up to its surface. Additional screening of 123 oropharyngeal mucosa samples from patients without evidence of acute EBV-infection, using the polymerase chain reaction for EBV-DNA detection combined with EBER- and BHLF1-ISH showed single latently infected lymphocytes in only one case. Our data imply that infected lymphocytes and not epithelial cells are, in fact, the reservoir for EBV infection, and that these are the cells that participate in the interindividual virus transfer.

Topics: Adolescent; Adult; B-Lymphocytes; Biomarkers; Biopsy; Child; Child, Preschool; Epithelium; Female; Gene Expression; Herpesvirus 4, Human; Humans; Immunophenotyping; In Situ Hybridization; Infectious Mononucleosis; Keratins; Macrophages; Male; Palatine Tonsil; Polymerase Chain Reaction; RNA, Small Nuclear; RNA, Viral; T-Lymphocytes; Transcription, Genetic; Virus Latency

Viruses have been postulated to be involved in the induction of autoantibodies by: autoimmunization with tissue proteins released by virally induced tissue damage; immunization with virally encoded antigens bearing molecular similarities to normal tissue proteins; or nonspecific (polyclonal) B cell stimulation by the infection. Infectious mononucleosis (IM) is an experiment of nature that provides the opportunity for examining these possibilities. We show here that IgM antibodies produced in this disease react with at least nine normal tissue proteins, in addition to the virally encoded Epstein-Barr nuclear antigen (EBNA-1). The antibodies are generated to configurations in the glycine-alanine repeat region of EBNA-1 and are crossreactive with the normal tissue proteins through similar configurations, as demonstrated by the effectiveness of a synthetic glycine-alanine peptide in inhibiting the reactions. The antibodies are absent in preillness sera and gradually disappear over a period of months after illness, being replaced by IgG anti-EBNA-1 antibodies that do not crossreact with the normal tissue proteins but that are still inhibited by the glycine-alanine peptide. These findings are most easily explained by either a molecular mimicry model of IgM autoantibody production or by the polyclonal activation of a germline gene for a crossreactive antibody. It also indicates a selection of highly specific, non-crossreactive anti-EBNA-1 antibodies during IgM to IgG isotype switching.

Topics: Alanine; Amino Acid Sequence; Antibody Specificity; Antigens, Viral; Autoantibodies; B-Lymphocytes; Cell Transformation, Viral; Epstein-Barr Virus Nuclear Antigens; Glycine; Herpesvirus 4, Human; Humans; Immunoglobulin M; Infectious Mononucleosis; Keratins; Repetitive Sequences, Nucleic Acid

Sera from patients with rheumatoid arthritis (RA), patients with infectious mononucleosis (IM), and blood donors were tested by indirect immunofluorescence for the presence of antikeratin antibody (AKA), antibody to cytoskeletal intermediate filaments of prekeratin or vimentin type (AIFA) and antiperinuclear factor (APF). In 81.9% of the RA sera and 92.5% of the IM sera AIFA of IgM class was found at titres up to and in some cases exceeding 1/160. In blood donors the incidence of AIFA was 26%, at titres not exceeding 1/20. AKA and APF, always of IgG class, were found in 54.2% and 73.6% of rheumatoid sera. A weak correlation was found in RA between the incidence of AIFA and APF. AKA was not present in either IM or blood donor sera, and APF was found in only 2.5% and 3.2% of IM or blood donors respectively.

Topics: Antibodies, Antinuclear; Arthritis, Rheumatoid; Autoantibodies; Humans; Infectious Mononucleosis; Intermediate Filament Proteins; Keratins; Protein Precursors; Vimentin