TABLE 4.

Serum ID50 titers in the absence and presence of MPER-derived peptides

SerumSample fractionVirusID50 for peptide:% Neutralization inhibited by test peptide:b
Mocka2F5.014E10.22MPR.032F5.014E10.22MPR.03
1Untreated plasmaHIV-2/C1<20<20<20<20
Untreated plasmaHIV-2/C12221101005555
6Untreated plasmaHIV-2/C14051201005075
Untreated plasmaHIV-2/C155492110116282
gp120 Ab-depleted fractioncSF16259637700
19Untreated plasmaHIV-2/C1281276427228574
Untreated plasmaHIV-2/C124318369110257255
Untreated serumHXBc21,0057206282838
gp120 Ab-depleted fractionHXBc2827920476
gp120 Ab-depleted fractionSF162<20<20<20
20Untreated plasmaHIV-2/C156351234.824.999496
Untreated plasmaHXBc24,4015,4471,528065
gp120 Ab-depleted fractionHXBc216917720088
gp120 Ab-depleted fractionSF16244942940491
gp120 Ab-depleted fractionBaL.01252027200
Untreated plasmaJRFL1,2861,583977024
gp120 Ab-depleted fractionJRFL405610075
30Untreated plasmaHIV-2/C165160025048686225
Untreated plasmaHIV-2/C1928426372737546021
45Untreated plasmaHIV-2/C120.120101005050
Untreated plasmaHIV-2/C158.371.7404003131
gp120 Ab-depleted fractionHXBc2565344621
gp120 Ab-depleted fractionSF162179106266410
B7B5Untreated plasmaHIV-2/C13,2041,659487867488573
gp120 Ab-depleted fractionHXBc23,9533,7665,4134,479500
  • a Mock peptide (defined as an equivalent volume of PBS) was used as a negative control.

  • b Indicator of peptide-specific neutralizing antibody response; calculated as [1 − (ID50 with test peptide)/ID50 with mock peptide)] × 100. Values higher than 50% are shown in boldface type.

  • c The fraction of serum that was adsorbed with gp120-coupled Dynabeads prior to the neutralization assay.