This Article Full Text (PDF) Other Versions of this Article: JVI.01544-06v1 81/8/3757    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Shibata, J. Articles by Matsushita, S. Search for Related Content PubMed PubMed Citation Articles by Shibata, J. Articles by Matsushita, S.

 Previous Article  |  Next Article 

J. Virol. doi:10.1128/JVI.01544-06
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.

Impact of V2 mutations for escape from a potent neutralizing anti-V3 monoclonal antibody during in vitro selection of a primary HIV-1 isolate

Division of Clinical Retrovirology and Infectious Diseases, Center for AIDS Research, Kumamoto University, Kumamoto 860-0811, and The Chemo-Sero-Therapeutic Research Institute, Kyokushi, Kikuchi, Kumamoto 869-1298, Japan

^* To whom correspondence should be addressed. Email: shuzo{at}kaiju.medic.kumamoto-u.ac.jp.

	Abstract

KD-247, a humanized monoclonal antibody (MAb) to an epitope of gp120-V3-tip, has potent cross-neutralizing activity against subtype B primary human immunodeficiency virus type 1 (HIV-1) isolates. To assess how KD-247 escape mutants can be generated, we induced escape variants by exposing bulked primary R5 virus, MOKW, to increasing concentrations of KD-247 in vitro. In the presence of relatively low concentrations of KD-247, viruses with two amino acid (aa) mutations (R166K/D167N) in V2 expanded, and under high KD-247 pressure, a V3-tip substitution (P313L) emerged in addition to the V2 mutations. However, a virus with a V2 175P mutation dominated during passaging in the absence of KD-247. Using domain swapping analysis, we demonstrated that the V2 mutations and the P313L mutation in V3 contribute to partial and complete resistant phenotypes against KD-247, respectively. To identify the V2 mutation responsible for the resistance to KD-247, we constructed pseudoviruses with single or double aa mutations in V2 and measured their sensitivity to neutralization. Interestingly, the neutralization phenotypes were switched, so that the 175th aa (Pro or Leu) located in the center of V2 was exchanged, indicating that the 175th aa has a crucial role; dramatically changing the Env oligomeric state on the membrane surface and affecting the neutralization phenotype against not only anti-V3 antibody but also rsCD4. These data suggested that HIV-1 can escape from anti-V3 antibody attack by changing the conformation of the functional envelope oligomer by acquiring mutations in the V2 region in environments with relatively low antibody concentrations.