Expression and assembly of hepatitis B virus proteins in cultured insect cells.
Item
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Title
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Expression and assembly of hepatitis B virus proteins in cultured insect cells.
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Identifier
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AAI8801742
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identifier
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8801742
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Creator
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Mohamad, Adel Abdel-Raouf.
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Contributor
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Adviser: George Acs
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Date
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1987
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Language
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English
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Publisher
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City University of New York.
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Subject
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Biology, Molecular
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Abstract
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The baculovirus Autographa californica Nuclear Polyhedrosis Virus (AcNPV) has been used to express various hepatitis B virus (HBV) proteins in cultured insect cells in order to study their properties, interaction and assembly into virus-related particles. Recombinant baculoviruses AcNPV-S, AcNPV-S2S, AcNPV-S1S2S and AcNPV-PCC containing HBV DNA coding sequences for the envelope proteins have been produced. Infection of cultured insect cells with AcNPV-S or AcNPV-S2S resulted in similarly high levels of expression and secretion of hepatitis B surface antigen (HBsAg) particles. Infection of the insect cells with AcNPV-S1S2S resulted in expression of the HBV L envelope protein in both glycosylated and unglycosylated forms. The expressed L protein failed to be secreted or assembled into HBsAg particles and was retarded inside the cells in association with the cell membranes. Co-infection of the insect cells with AcNPV-S1S2S along with AcNPV-S and AcNPV-S2S resulted in co-expression of the three HBV envelope proteins and co-assembly and secretion of small amounts of unusual HBsAg particles that were made of all three HBV envelope proteins. Infection of the insect cells with AcNPV-PCC resulted in expression of HBV precore-core proteins which were readily secreted into the medium bearing both HBeAg and HBcAg antigenicities. Immunochemical characterization of the secreted precore-core proteins indicated the presence of 26, 22, 19 and 17 kd polypeptides. The cytoplasm of these cells contained only the 26 kd protein. This indicated that expression of the precore sequences did not inhibit but rather acted as a signal peptide to facilitate the secretion of precore-core proteins which were then processed into smaller core-related proteins. While the expression of the (L) envelope protein inhibited the secretion of the (M) and (S) proteins as HBsAg particles, co-expression of both the (L) envelope protein and the precore-core proteins did not result in any inhibitory effect on the secretion of the precore-core proteins. This indicated the specificity of the interaction between the envelope proteins.;This work provides a unique molecular approach to study the process and the factors involved in the assembly of HBV as well as other viruses. (Abstract shortened with permission of author.).
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
