RESUMO
We have constructed recombinant adenoviruses (Ad), with functional or defective E1a genes, which harbor either the hepatitis B (HB) virus s gene encoding the HB surface antigen, as well as the pre-S2 epitopes, or the bacterial gene encoding chloramphenicol acetyltransferase (CAT) under control of the Ad major late promoter (MLP). The recombinant viruses defective for E1a (Ad.MLP.S2 and Ad.CAT), which can be efficiently propagated only on 293 cells that complement this defect, and the nondefective (Ad.MLP.S2.E1A) recombinant were used to infect a wide spectrum of cells of different origin. The yields of HBs and CAT proteins obtained with these different recombinant viruses demonstrate no real advantage to using nondefective vectors, whatever the cell type infected. The injection into chimpanzees of Ad.MLP.S2 does not elicit the production of antibodies, but can immunologically prime the animals, resulting in a partial protection against HBV challenge.
Assuntos
Adenovírus Humanos/genética , Vetores Genéticos , Antígenos de Superfície da Hepatite B/genética , Adenovírus Humanos/fisiologia , Animais , Sequência de Bases , Linhagem Celular , Cloranfenicol O-Acetiltransferase/genética , DNA Recombinante/genética , Vírus Defeituosos/genética , Expressão Gênica/genética , Hepatite B/prevenção & controle , Antígenos de Superfície da Hepatite B/biossíntese , Antígenos de Superfície da Hepatite B/imunologia , Vacinas contra Hepatite B , Humanos , Camundongos , Dados de Sequência Molecular , Pan troglodytes , Regiões Promotoras Genéticas , Coelhos , Células Tumorais Cultivadas , Vacinas Sintéticas , Vacinas contra Hepatite Viral , Replicação ViralRESUMO
We have developed an adenovirus vector to express foreign proteins under the control of the adenovirus E1a promoter. Two recombinant plasmids, harbouring either the S gene or the pre-S2 region and the S gene of hepatitis B virus under the control of the E1a promoter, were used to construct two recombinant adenoviruses. These two viruses direct the synthesis of hepatitis B virus surface antigen (HBsAg) particles during the time course of an infectious cycle. When the pre-S2 region is present in the constructed virus, the synthesis of particles carrying the receptor for polymerized human serum albumin (pHSA) is observed. Moreover, the inoculation of rabbits with this latter purified recombinant adenovirus elicits the production of antibodies that react with both HBsAg and pHSA receptor.