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PubMed Research Article. “Identification and structural characterization of novel genetic elements in the HIV-1 V3 loop regulation coreceptor usage” by Svicher et al. Studied the interaction between HIV-1gp120 and CCR5 N terminus. HIV-1 entry involves gp120, CD4 recepor and CCR5 or CXCR4.
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PubMed Research Article • “Identification and structural characterization of novel genetic elements in the HIV-1 V3 loop regulation coreceptor usage” by Svicher et al. • Studied the interaction between HIV-1gp120 and CCR5 N terminus
HIV-1 entry involves gp120, CD4 recepor and CCR5 or CXCR4 • V3 loop is determining factor in coreceptor usage • Composed of 3 regions • Base • Stem • Hairpin crown • V3 positions 11, 24 and 25 bind with different coreceptors but mechanism that differentiates is not know
V3 base interaction with CCR5 critical for infection • Increased affinity of V3 for CCR5 • Study population: 323 blood samples from 323 HIV-1 patients • V3 mutation was tested for along with wild-type residues to see different coreceptor usage • Structural analysis taken from Huang et al. CCR5 model with HIV-1 gp120
V3 sequence determines coreceptor usage • 19 V3 sequence positions that correlated to CCR5 of CXCR4 usage • Of 29 mutations, 6 are at the V3 positions of 11, 24 and 25 select for CCR5 • 23 other mutations at 15 V3 positions select for CXCR4 • Mutations for CCR5 not seen in viruses that select for CXCR4 and vice versa • Less that 1% of mutation in each case