RESUMO
Fragments of hepatitis B virus envelope proteins corresponding to the parts of the pre-S domain were synthesised and immobilized on the carriers with low own immunogenicity. The highest stimulation of the antibody production was observed for the antigens immobilized on microspherical carriers or gelatin modified by H-Gly-Tyr-OH. Among peptides used for immunization, pre-S fragment 134-144, conjugated with microspherical carrier, proved to be the most active.
Assuntos
Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/imunologia , Fragmentos de Peptídeos/imunologia , Proteínas do Envelope Viral/imunologia , Sequência de Aminoácidos , Animais , Ensaio de Imunoadsorção Enzimática , Cobaias , Antígenos de Superfície da Hepatite B/genética , Vírus da Hepatite B/genética , Imunização , Immunoblotting , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Proteínas do Envelope Viral/síntese químicaRESUMO
The antigenic structure of HIV proteins was analyzed semiempirically. Peptides mimicking fragments of the main structural HIV-1 proteins (p17, p24, gp41, and gp120) were selected and synthesized, with account taken of the level of conservation of various HIV genome fragments. The synthesized peptides were then subjected to immunological study with human sera in an enzyme-linked immunosorbent assay (ELISA). Peptides from two regions were found to be particularly immunoreactive with sera from HIV-1 infected persons: the C-terminal end of gp120 and a sequence approximately sixty to eighty amino acids in from the N-terminus of gp41. In fact, more than 96% of HIV-1 positive sera reacted with peptide 495-516 of gp120 (SP-III), peptide 584-602 of gp41 (LS-19), and peptide 601-616 of gp41 (SP-15). Additionally, twelve out of twelve serum samples from Ugandans infected with HIV-1 reacted with both SP-III (from HTLV-III) and SP-29 (gp41, 598-609; from the LAV-ELI isolate), suggesting that these immunodominant sites are useful diagnostically irrespective of the infecting isolates. HIV-2 peptides were also synthesized, and immunoreactivity and cross-reactivity examined. Only two peptides (581-603 of gp32 and 592-605 of gp32) reacted with all of the six HIV-2 positive sera tested. These peptides did not react with HIV-1 positive sera or control sera from healthy blood donors.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Antígenos HIV , Infecções por HIV/diagnóstico , Fragmentos de Peptídeos/imunologia , Sequência de Aminoácidos , Ensaio de Imunoadsorção Enzimática , Anticorpos Anti-HIV/isolamento & purificação , Antígenos HIV/química , Infecções por HIV/imunologia , HIV-1/imunologia , HIV-2/imunologia , Humanos , Dados de Sequência Molecular , Fragmentos de Peptídeos/síntese química , Fragmentos de Peptídeos/química , Homologia de Sequência do Ácido NucleicoRESUMO
With the aid of monoclonal antibodies to the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1), low-molecular-mass subunits (p29, p32, and p40) were identified in HIV-1 RT purified from HIV (HTLV-IIIB) virions by isoelectric focusing. Epitope mapping with synthetic polypeptides from various regions of the pol gene suggests that the low-molecular-mass subunits result from N-terminal cleavage of the p51 subunit. The subunits could be separated only by SDS-polyacrylamide gel electrophoresis and detected by immunoblotting. They could not be separated on chromatographic columns, suggesting that the subunits are complexed or conformationally arranged in such a way that their separation on the basis of molecular mass is not possible. The molecular mass of the active enzyme eluted from a chromatographic column (Sephacryl S-300) loaded with a mixture of the subunits was estimated to be 100 kDa.
Assuntos
Antígenos HIV/química , HIV-1/enzimologia , DNA Polimerase Dirigida por RNA/imunologia , Animais , Anticorpos Monoclonais , Epitopos/química , Genes pol , Transcriptase Reversa do HIV , HIV-1/genética , HIV-1/imunologia , Imunoquímica , Camundongos , Peso Molecular , Mapeamento de Peptídeos , Conformação Proteica , DNA Polimerase Dirigida por RNA/química , DNA Polimerase Dirigida por RNA/genéticaRESUMO
Seventy-five per cent of sera from HIV-1-infected individuals bind to the human B-lymphoma cells bearing the major histocompatibility class II molecule in enzyme-linked immunosorbent assay (ELISA). The binding is caused by the antibodies against the class II molecule present in the serum samples which prevent the interaction of murine anti-HLA.DR monoclonal antibody with B lymphoma in FACS analysis. The three highly conserved amino acid sequences in alpha- and beta-chains of the class II molecule and three homologous fragments in HIV-1 gp120 and gp41 were identified by computer search and synthesized. Using these peptides it was demonstrated that 28-48% of HIV-positive sera contain antibodies that cross-react with the peptide of HIV-1 origin and with the peptide from the class II molecule as well.