The envelope glycoproteins are the principal targets for humoral immunity against HIV-1 infection, and are therefore a major focus of vaccine development. Although the envelope glycoproteins can be expressed as recombinant proteins that are immunogenic, it appears that these proteins are insufficient to provide protective immunity to HIV-1 infection. One contributing factor is the inability of envelope glycoproteins to elicit antibodies able to neutralize primary HIV-1 isolates with significant potency, despite their ability to induce antibodies able to neutralize T-cell line adapted strains. Despite the presence of neutralizing antibody epitopes on the recombinant proteins, the inefficiency with which antibodies against these epitopes are generated in humans may compromise the practical efficacy of these immunogens. Understanding the basis of these observations would facilitate the design of a new generation of immunogens that might better elicit antibodies effective against primary HIV-1 isolates. The principal investigator's approach to the problem is to gain a better understanding of the structure of the envelope glycoproteins, to learn how key neutralizing antibody epitopes are presented on these proteins. The methods he has chosen probe the topology of both monomeric and oligomeric forms of gp120 and gp160 with monoclonal antibodies against continuous and discontinuous epitopes that he is able to partially or totally define. He will study not only the envelope glycoproteins of T-cell line-adapted strains that were used in the first generation of subunit vaccines, but also proteins derived from primary isolates. As well as gp120 monomers, he will investigate the conformation of soluble gp160 molecules that contain the gp120 moiety linked to the ectodomain of gp41, because proteins of this type are under consideration as vaccine immunogens. He will also study the conformation of the envelope glycoproteins in their most native forms on the surfaces of virions and virus-infected cells. These studies are aimed at increasing our understanding of the antigenicity and immunogenicity of key viral proteins involved in the generation of humoral immunity against HIV-1, and may provide information to facilitate the development of new generations of HIV vaccines with improved performance.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI039420-03
Application #
2672698
Study Section
AIDS and Related Research Study Section 1 (ARRA)
Project Start
1996-05-01
Project End
2000-04-30
Budget Start
1998-05-01
Budget End
1999-04-30
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Aaron Diamond AIDS Research Center
Department
Type
DUNS #
786658872
City
New York
State
NY
Country
United States
Zip Code
10016
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Kassa, Aemro; Finzi, Andres; Pancera, Marie et al. (2009) Identification of a human immunodeficiency virus type 1 envelope glycoprotein variant resistant to cold inactivation. J Virol 83:4476-88
Yang, Xinzhen; Lipchina, Inna; Lifton, Michelle et al. (2007) Antibody binding in proximity to the receptor/glycoprotein complex leads to a basal level of virus neutralization. J Virol 81:8809-13
Yang, Xinzhen; Lipchina, Inna; Cocklin, Simon et al. (2006) Antibody binding is a dominant determinant of the efficiency of human immunodeficiency virus type 1 neutralization. J Virol 80:11404-8
Yuan, Wen; Bazick, Jessica; Sodroski, Joseph (2006) Characterization of the multiple conformational States of free monomeric and trimeric human immunodeficiency virus envelope glycoproteins after fixation by cross-linker. J Virol 80:6725-37
Xiang, Shi-Hua; Farzan, Michael; Si, Zhihai et al. (2005) Functional mimicry of a human immunodeficiency virus type 1 coreceptor by a neutralizing monoclonal antibody. J Virol 79:6068-77
Mische, Claudia C; Yuan, Wen; Strack, Bettina et al. (2005) An alternative conformation of the gp41 heptad repeat 1 region coiled coil exists in the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor. Virology 338:133-43
Ren, Xinping; Sodroski, Joseph; Yang, Xinzhen (2005) An unrelated monoclonal antibody neutralizes human immunodeficiency virus type 1 by binding to an artificial epitope engineered in a functionally neutral region of the viral envelope glycoproteins. J Virol 79:5616-24

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