RESUMO
Nonstructural protein 3 (NS3) of human hepatitis C virus (HCV) is a conserved multi-functional protein essential for replication and translation of viral RNA and polyprotein processing. Early T-cell response against NS3 is capable of restricting viremia. We aimed at characterizing the immunogenicity in gene immunization of the conserved regions of NS3 critical for protein folding and activity. C57BL/6 mice were injected with NS3 gene of Russian HCV 1b isolate 274933RU. Immunization did not exert any overt histological changes and had no long-term effects on the immune status of NS3 gene-recipients. The immune response in NS3 gene-recipients was screened by antibody ELISA, T-cell proliferation test and immune assays for specific cytokine production. T-lymphocytes of NS3 gene-recipients proliferated in response to peptides representing conserved regions of protease and ATPase/helicase. Stimulated T-lymphocytes produced IL-2, and in response to protease-derived peptides, also IFN-gamma. Potent and long-lasting antibody response was raised against conserved NS3 regions including "Greek-key" motif of protease, motifs II, V and polynucleotide-binding domains of ATPase/helicase. Thus, gene immunization effectively targeted conserved regions critical for NS3 protease and helicase function. In type and specificity, immune response of NS3 gene-immunized mice mimicked immunity achieved in the acute self-limiting HCV infection of human and primates and in virus-exposed healthy individuals, indicating promiscuity of NS3 as immunogen.
Assuntos
Anticorpos Anti-Hepatite C/imunologia , Vacinas de DNA/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Adenosina Trifosfatases/química , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/imunologia , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Sequência Conservada , Citocinas/biossíntese , DNA Helicases/química , DNA Helicases/genética , DNA Helicases/imunologia , Anticorpos Anti-Hepatite C/sangue , Hepatite C Crônica/imunologia , Humanos , Imunização , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos C57BL , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Coelhos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Alinhamento de Sequência , Serina Endopeptidases/química , Serina Endopeptidases/genética , Serina Endopeptidases/imunologia , Linfócitos T/imunologia , Proteínas não Estruturais Virais/químicaRESUMO
Today, the most adequate and complete explanation of the main phenomena of clinico-immunological disease picture was suggested by D. Ho and his team (1998). According to their model, HIV infection is not slow infection, but acute productive process, lasting for many years with development AIDS. First of all, in this process specific cytotoxic lymphocytes and antibody-dependent cell cytotoxicity play an active role, as well as apoptotic processes, hyperproduction of pro-inflammatory cytokines, development of autoimmune disorders, direct cytotoxic action of envelope viral proteins The investigations, carried out in Scientific Educational and Industrial Complex "Clinical Immunology" of Rostov-Don State Medical University, have shown that the changes of macrophage functional activity during HIV infection are in dependence upon many factors, especially patient's age. The progression of HIV infection is accompanied with increase of CD95 expression on all lymphocytes, but especially on CD4(+) subpopulation at the stage of AIDS-associated infections. In this group of lymphocytes there is the highest number of cells with DNA degradation that is characteristic of terminal phase of apoptosis. It is possible to make a conclusion that both the viral factors, and the functional features of patient's immune system have great importance for pathogenesis of one or another variant of HIV infection course.
