RESUMO
Human apolipoprotein H (apo H) was found to bind specifically to hepatitis B surface antigen (HBsAg) from hepatitis B virus (HBV)-infected individuals. We used recombinant HBsAg proteins to analyze HBV domains recognized by apo H. We showed that the myristylated pre-S1 domain of HBsAg strongly interacted with apo H. This binding involved phospholipid components of the HBV envelope because their removal by detergent prevented apo H-HBsAg interaction. The opposite effects of iron and zinc metal ions on binding suggest that the oxidation of phospholipids also affects apo H-HBsAg interaction. After fractionation of viral particles on a sucrose gradient, and their addition to microtiter plates coated with apo H or anti-HBsAg, we observed that the maximal anti-HBsAg capture activity corresponded to a sucrose concentration of 36%, whereas the maximal apo H capture activity corresponded to a concentration of 39%. Electron microscopy and polymerase chain reaction (PCR) Southern blot studies of these fractions showed that the fraction with maximal apo H binding predominantly contained full Dane particles. Finally, we studied apo H-HBsAg binding relative to the presence of hepatitis B virus markers and observed that apo H binding activity for HBsAg was higher in sera from patients in the active virus replication phase.
Assuntos
Glicoproteínas/metabolismo , Vírus da Hepatite B/metabolismo , Animais , Southern Blotting , Linhagem Celular , DNA Viral/metabolismo , Glicoproteínas/sangue , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/química , Antígenos de Superfície da Hepatite B/metabolismo , Vírus da Hepatite B/genética , Humanos , Técnicas Imunoenzimáticas , Substâncias Macromoleculares , Microscopia Eletrônica , Oxirredução , Fosfolipídeos/metabolismo , Reação em Cadeia da Polimerase , Proteínas Recombinantes/sangue , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Spodoptera/citologia , beta 2-Glicoproteína IRESUMO
IgG antibodies of autoimmune SLE (Systemic Lupus Erythematosus) serum S detected a HeLa hnRNP 72 kDa protein, cross-reacting with the retroviral (MLV) p15-gag polypeptide. Since serum S disclosed a ubiquitous 72 kDa antigen in HeLa cell fractions, was prepared the so-called cytoplasmic "X fraction", enriched for the 72 kDa protein, defined here as p72. This autoantigen was detected by antibodies of HIV 1+ patients, recently of seroconverted (RSC) asymptomatic subjects, of HBV+ sera, and of primary Gougerot-Sjögren (prGS) sera. The presence of these autoantibodies in different autoimmune and infectious pathologies raises the question of the involvement of p72 in the immune processes and in the early HIV1 infection.
Assuntos
Antígenos Virais/imunologia , Autoanticorpos/imunologia , Produtos do Gene gag/imunologia , Imunoglobulina G/imunologia , Síndrome da Imunodeficiência Adquirida/imunologia , Reações Cruzadas/imunologia , HIV-1 , Células HeLa , Hepatite B/imunologia , Humanos , Lúpus Eritematoso Sistêmico/imunologia , Síndrome de Sjogren/imunologiaRESUMO
With incubation at 45 degrees C, human peripheral blood lymphocytes (PBL) loose 80% of their capacity to form 1-hr autorosettes (AR). However, the addition of supernatant from heated lymphocytes (SHL) restores 93% of their rosette-forming capacity, while producing an inhibitory effect on nonincubated lymphocytes. A soluble factor present in SHL is active to a 1/5000 dilution; is absorbable on autologous red blood cells but not on sheep red blood cells; is RNase and DNase resistant and sensitive to trypsin and pronase; and acts variably on allogenic cells.
