Biological and immunological properties of human immunodeficiency virus type 1 envelope glycoprotein: analysis of proteins with truncations and deletions expressed by recombinant vaccinia viruses.
The effects of C-terminal and internal deletions on the synthesis, transport, biological properties, and antigenicity of the human immunodeficiency virus type 1 envelope protein were determined. A family of recombinant vaccinia viruses that express N-terminal overlapping env proteins of 204, 287, 393, 502 (full-length gp120), 635, 747, and 851 (full-length gp160) amino acids was constructed. All of the proteins were detected in intra- and extracellular forms which differed in the extent of glycosylation. The 747- and 851-amino-acid proteins were cleaved, were expressed on the surface of infected cells, and bound CD4. The 635-amino-acid env protein was cleaved inefficiently, and both the precursor and product were secreted, indicating absence of the transmembrane sequence. The 635- as well as the 502-amino-acid protein, which was also largely secreted, could still bind CD4. Unexpectedly, the 393-amino-acid protein was anchored in the plasma membrane, but neither it nor smaller proteins bound to soluble CD4. When amino acids at the gp120-gp41 junction were deleted, proteolytic cleavage of gp160 did not occur. Nevertheless, gp160 was inserted into the plasma membrane and bound soluble CD4. The predominant conserved B-cell epitopes were mapped to gp41 and the C terminus of gp120, whereas cytotoxic T-cell epitopes were distributed throughout the length of the glycoproteins.
Earl
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PL
Laboratories of Viral Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
Koenig
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S
Moss
B
B
D000818:Animals; D015704:CD4 Antigens / Q000276:immunology; D002460:Cell Line; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D005455:Fluorescent Antibody Technique; D005814:Genes, Viral; D006679:HIV Seropositivity; D015497:HIV-1 / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D006801:Humans; D016297:Mutagenesis, Site-Directed; D011995:Recombination, Genetic; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics*; D014759:Viral Envelope Proteins / Q000032:analysis / Q000235:genetics*
D015704:CD4 Antigens; D014759:Viral Envelope Proteins