Regulation of the susceptibility of HIV-1 to a neutralizing antibody KD-247 by nonepitope mutations distant from its epitope
| Autor: | Shigeru Kusagawa, Mitsuo Honda, Naoki Yamamoto, Mari Takizawa, Kosuke Miyauchi, Katsuhiko Kitamura, Jun Komano, Emiko Urano, Satoshi Naganawa, Toshio Murakami |
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| Rok vydání: | 2011 |
| Předmět: |
Protein Conformation
DNA Mutational Analysis Immunology HIV Antibodies HIV Envelope Protein gp120 V3 loop Biology Antibodies Monoclonal Humanized medicine.disease_cause Epitope Epitopes Imaging Three-Dimensional Protein structure Neutralization Tests medicine Humans Immunology and Allergy Neutralizing antibody Gene Mutation Virion Chromosome Mapping virus diseases Antibodies Neutralizing Virology Peptide Fragments Infectious Diseases Monoclonal HIV-1 biology.protein Antibody |
| Zdroj: | AIDS. 25:2209-2216 |
| ISSN: | 0269-9370 |
| Popis: | A humanized neutralizing antibody, KD-247, targets the V3 loop of HIV-1 Env. HIV-1 bearing the GPGR sequence at the V3 loop is potentially susceptible to KD-247. However, not all GPGR-positive HIV-1 isolates are neutralized by KD-247. We examined the potential mechanism by which the susceptibility of HIV-1 to KD-247-mediated neutralization is regulated.We searched for nonepitope neutralization regulatory (NNR) mutations that sensitize GPGR-bearing HIV-1AD8 to KD-247 and mapped the locations of such mutations relative to the V3 loop.: We generated a functional HIV-1AD8 Env library, and evaluated the viral susceptibility to KD-247 by measuring the half-inhibitory concentration (IC50) to KD-247 on TZM-bl cell assay.We identified nine KD-247-sensitizing NNR mutations from 30 mutations in various regions of gp120, including the V1/V2 loop, C2, V3 loop, C4, and C5. They specifically affected KD-247-mediated neutralization, as they did not affect the b12-mediated neutralization. When combined, the KD-247-sensitizing NNR mutations additively sensitized the virus to KD-247 by up to 10 000 folds. The KD-247-sensitizing NNR mutations increased KD-247 binding to the virion. Notably, the NNR mutation in C4 coincides with the CD4-binding site of gp120.Given that most of the KD-247-sensitizing NNR mutations are remote from V3 loop, it is reasonable to hypothesize that the steady-state, local conformation of the V3 loop is regulated by the interdomain contact of gp120. Our mutational analysis complements crystallographic studies by helping provide a better understanding of the steady-state conformation and the functional geometry of Env. |
| Databáze: | OpenAIRE |
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