Research ArticleHIV

Partial efficacy of a broadly neutralizing antibody against cell-associated SHIV infection

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Science Translational Medicine  09 Aug 2017:
Vol. 9, Issue 402, eaaf1483
DOI: 10.1126/scitranslmed.aaf1483
  • Fig. 1. Establishment of cell-associated SHIVSF162P3 stock and challenge of macaques infused with PGT121 or isotype control.

    (A) A SHIVSF162P3-naïve pigtail macaque was challenged with cell-free virus via the intravenous route. The graph depicts the animal’s plasma VL over 2 weeks after challenge. The time point enclosed by the block reflects the 2-week time point when the animal was euthanized, and its splenocytes were harvested to serve as a challenge stock of cell-associated virus against animals not infused with antibody or infused with an immunoglobulin 1 (IgG1) isotype control antibody (n = 5) or animals infused with the PGT121 BnAb (n = 6). (B) The graph depicts the VLs of animals not infused with antibody (dotted blue line) or infused with IgG1 isotype control (solid blue lines) 1 hour before challenge with cell-associated SHIVSF162P3. (C) The VLs of PGT121-infused macaques that remained uninfected (solid red lines) or became infected (dotted red lines) after cell-associated virus challenge are depicted in the graph. (D) An additional six macaques were infused with PGT121 1 hour before being intravenously challenged with cell-free SHIVSF162P3. The postchallenge VLs of these six animals are depicted in the graph (solid green lines). The dotted black lines in all graphs represent the sensitivity cutoff for the VL assay used.

  • Fig. 2. Seroconversion of macaques challenged with cell-associated or cell-free SHIVSF162P3.

    An enzyme-linked immunosorbent assay (ELISA) was used to screen serial plasma samples from no antibody/isotype control– or PGT121-infused animals challenged with cell-associated or cell-free SHIVSF162P3 for the presence of antibodies against the gp41 portion of viral envelope. The relative ODs for 1:1000 dilutions of plasma samples from the first 8 weeks after challenge are depicted in the graphs for (A) the no antibody/isotype control–infused macaques challenged with cell-associated virus, (B) PGT121-infused animals challenged with cell-associated virus, and (C) PGT121-infused animals challenged with cell-free virus. The dotted black line on all graphs represents the cutoff OD for the ELISA, which was defined as three times the OD of gp41-coated wells with a SHIVSF162P3-uninfected plasma sample.

  • Fig. 3. Plasma concentrations of infused PGT121 BnAb.

    An ELISA to detect gp120-binding antibodies was used to screen preseroconversion serial plasma samples from animals infused with PGT121 (red or green data points) or isotype control antibodies (blue data points) and determine plasma concentrations of PGT121. (A) The graph depicts the relative amounts of PGT121 antibody in macaques infused with PGT121 or isotype control antibody at the week 0 time point (preinfusion) before antibody infusion and 30 min after antibody infusion (postinfusion) in protected and nonprotected animals. Actual measurements of plasma PGT121 at 30 min after infusion were available for six protected animals (4294, CC63, 8DF8, B7DA, AFIC, and D782). For the other six animals (O196, BDD4, 45BE, O439, 4B31, and DEF1), the postinfusion PGT121 concentrations were extrapolated from measured week 1 postinfusion concentrations using the average rate of decay between 30 min and 1 week after infection in the six animals for which early postinfusion concentrations were measured. (B) The graph depicts the relative plasma concentrations of PGT121 at detectable preseroconversion serial time points for all 12 animals infused with PGT121.

  • Fig. 4. Assessment of infectiousness of SHIVSF162P3-challenged animals by transfer of PBMCs to uninfected macaques.

    To assess the infectiousness of several animals after challenge, about 20 × 106 PBMCs were injected intravenously into uninfected macaques. Newly challenged macaques were followed for viremia. (A to F) The pairs of graphs show the VLs of the PBMC source animals at the time points used for the challenge (time points in black boxes in top graphs) and VLs after PBMC challenge in the intravenously challenged animals (bottom graphs). (A) This graph represents transfer of PBMCs from an infected animal with controlled viremia (F2F0) into an uninfected animal (CC63). (B and C) These graphs depict transfers of PBMCs from two uninfected animals, 4B31 (B) and CC63 (C), into two additional uninfected animals (8DF8 and 4B31, respectively). (D) The graph shows the transfer of PBMCs from an infected animal (0196), from a time point before appearance of high viremia, to an uninfected animal (4294). (E and F) These graphs depict transfers of PBMCs from an animal with prolonged delay in viremia (45BE) into two uninfected animals, DEF1 (E) and 0439 (F). (A to F) The dotted black lines in all graphs represent the sensitivity cutoff for the VL assay used.

  • Fig. 5. Diversity of envelope transmission variants.

    (A) Distribution in the number of sequences observed for each transmission variant (represented by a segment of the bar chart), as determined by phylogenetic analysis of the Env region sequences. The number of different transmission variants observed for each animal is shown above each bar. (B) Distribution in the estimated total number of transmission variants across four groups of animals: PGT121-infused animal with no viremia until week 8 (45BE), PGT121-infused animals with 1- to 2-week viremia (O196 and BDD4), control animals (F2F0, 19F9, D77C, FACA, and 658D), and the donor animal (8FC8). Extrapolated diversities were calculated on the basis of the distribution of the observed multiple variants. The interquartile range, minimum and maximum (box-and-whisker plots), and mean (+) for the estimated diversity for each group of animals are shown. The shaded boxes represent the minimum lower limit and maximum upper limit of the 95% CI for the estimated diversity across all animals per group.

  • Table 1. MHC haplotypes of cell-associated SHIV donor and PGT121-infused macaques.

    DonorRecrudescent virusNo recrudescent virus
    Animal8FC8019645BEBDD442940439CC63
    A1A052A082A052A052A052UnknownA053
    A2UnknownA052A082A040A019A082A082
    B1B101B015bB004bB004bB004bB007B019
    B2B007B024B118cB118cB013B118bB118b
    DRB1DR105DR05DR12bDR12bDR12bDR108DR18
    DRB2DR108DR106DR106DR123DR100DR110DR110
  • Table 2. Neutralization sensitivity of breakthrough viruses.

    IC50, 50% inhibitory concentration.

    IC50 (μg/ml) in TZM-bl cells
    SHIVSF162P3
    cell-associated
    virus stock
    (donor animal 8FC8)
    SHIVSF162P3
    breakthrough virus
    at 8 weeks
    (animal 45BE)
    SHIVSF162P3 breakthrough
    virus at 1 week
    (animal 0196)
    SHIVSF162P3 breakthrough
    virus at 1 week
    (animal BDD4)
    SHIVSF162P3
    virus stock
    PGT1210.030.030.020.020.09
    PG9>10>10>10>10>10
    CH01-310.470.450.371.032.74

Supplementary Materials

  • www.sciencetranslationalmedicine.org/cgi/content/full/9/402/eaaf1483/DC1

    Fig. S1. Analysis of differences in VLs after different SHIV challenges.

    Fig. S2. Animal infectiousness of the cell-associated SHIVSF162P3 stock challenge dose.

    Fig. S3. PGT121 binds to macaque FcγRs and activates NK cells.

    Fig. S4. ADCC of HIV-1–infected target cells by macaque PBMCs using PGT121.

    Fig. S5. Anti-gp120–binding antibodies in plasma samples of SHIVSF162P3-infected macaques.

    Fig. S6. FcγRIIIa-binding antibodies in plasma samples of SHIVSF162P3-infected macaques.

    Fig. S7. Markers of NK cell and T cell activation in PGT121-infused animals.

    Fig. S8. Gag-specific T cells in SHIVSF162P3-challenged macaques.

    Fig. S9. V3 loop sequence alterations in infected animals.

    Table S1. Characteristics of viral challenge stocks.

    Table S2. Sensitive VL measurements in PGT121-infused cell-associated challenged macaques.

    Table S3. Mutations within envelope.

    Table S4. Primary data.

  • Supplementary Material for:

    Partial efficacy of a broadly neutralizing antibody against cell-associated SHIV infection

    Matthew S. Parsons,* Sarah B. Lloyd, Wen Shi Lee, Anne B. Kristensen, Thakshila Amarasena, Rob J. Center, Brandon F. Keele, Jeffrey D. Lifson, Celia C. LaBranche, David Montefiori, Bruce D. Wines, P. Mark Hogarth, Kristine M. Swiderek, Vanessa Venturi, Miles P. Davenport, Stephen J. Kent*

    *Corresponding author. Email: skent{at}unimelb.edu.au (S.J.K.); mattp{at}unimelb.edu.au (M.S.P.)

    Published 9 August 2017, Sci. Transl. Med. 9, eaaf1483 (2017)
    DOI: 10.1126/scitranslmed.aaf1483

    This PDF file includes:

    • Fig. S1. Analysis of differences in VLs after different SHIV challenges.
    • Fig. S2. Animal infectiousness of the cell-associated SHIVSF162P3 stock challenge dose.
    • Fig. S3. PGT121 binds to macaque FcγRs and activates NK cells.
    • Fig. S4. ADCC of HIV-1–infected target cells by macaque PBMCs using PGT121.
    • Fig. S5. Anti-gp120–binding antibodies in plasma samples of SHIVSF162P3-infected macaques.
    • Fig. S6. FcγRIIIa-binding antibodies in plasma samples of SHIVSF162P3-infected macaques.
    • Fig. S7. Markers of NK cell and T cell activation in PGT121-infused animals.
    • Fig. S8. Gag-specific T cells in SHIVSF162P3-challenged macaques.
    • Fig. S9. V3 loop sequence alterations in infected animals.
    • Table S1. Characteristics of viral challenge stocks.
    • Table S2. Sensitive VL measurements in PGT121-infused cell-associated challenged macaques.
    • Table S3. Mutations within envelope.

    [Download PDF]

    Other Supplementary Material for this manuscript includes the following:

    • Table S4 (Microsoft Excel format). Primary data.

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