Research ArticleHEALTH AND MEDICINE

Anti-α4β7 monoclonal antibody–conjugated nanoparticles block integrin α4β7 on intravaginal T cells in rhesus macaques

See allHide authors and affiliations

Science Advances  21 Aug 2020:
Vol. 6, no. 34, eabb9853
DOI: 10.1126/sciadv.abb9853

Figures

  • Fig. 1 In vitro cell-binding study with NP-α4β7 gel.

    One-percent HEC gel loaded with 30.5 or 43.4 μg Ab/mg NPs (NP-α4β7 gel) was used to treat cells for 2 and 24 hours. The Cα4β7 shown in the graph represents the concentration of PE+ anti-α4β7 antibody. The data show representative histograms from a measurement of n = 3. The Y axis represents the number of cells/events, and the X axis represents the fluorescence intensity. The number above the gating line represents the percentage of PE+ RPMI 8866 cells in each histogram. (A) Unstained control. (B) cells treated with NP-IgG gel. (C) cells treated with NP-α4β7 gel (C = 1.2 μg/ml) for 2 hours. (D) cells treated with NP-α4β7 gel (C = 1.8 μg/ml) for 2 hours. (E) cells treated with NP-α4β7 gel (C = 1.2 μg/ml) for 24 hours. (F) cells treated with NP-α4β7 gel (C = 1.8 μg/ml) for 24 hours. (G) cells treated with α4β7 Ab (C = 1.2 μg/ml) for 2 hours. (H) cells treated with α4β7 Ab (C = 1.8 μg/ml) for 24 hours. C, the concentration of PE+ α4β7 Ab.

  • Fig. 2 Ex vivo blockage of α4β7 on CD4+ T cells in rhesus macaque vaginal explants by NP-α4β7 gel at two different antibody concentrations (0.3 and 1.5 mg/ml).

    The graph shows the percentage of unblocked α4β7 on cells in vaginal explant, quantified by staining the unblocked α4β7 with PE+ anti-α4β7 antibody. One-percent HEC gel loaded with 43.4 μg Ab/mg NPs (NP-α4β7 gel) was used for treatment. One-percent HEC gel loaded with 43.4 μg Ab/mg NPs (NP-IgG gel) was used as a control. The mean fluorescence intensity of PE+ anti-α4β7 antibody for each treatment group was normalized to the control group. Values represent means ± SD, n = 4. ***P < 0.001 and **P < 0.01 compared with NP-IgG gel.

  • Fig. 3 Schematic illustration of the treatment and sampling schedule for rhesus macaques.

    D, day; Bx, biopsy. Photo credit: the photo “Rhesus macaques—Lion Hill, Hong Kong” was taken by cattan2011, acquired from Creative Commons, licensed under CC BY2.0 (free to share and adapt for any purpose, even commercially), and used without any modification. Photo link: https://ccsearch.creativecommons.org/photos/b4e1870b-7d54-485a-81d4-3c9e0fbc2137; license link: https://creativecommons.org/licenses/by/2.0/?ref=ccsearch&atype=rich.

  • Fig. 4 In vivo blockage of α4β7 on tissues by NP-α4β7 gel at an antibody concentration of 1.5 mg/ml in a rhesus macaque model.

    One-percent HEC gel loaded with 43.4 μg Ab/mg NPs (NP-α4β7 gel) was used for treatment. One-percent HEC gel loaded with 43.4 μg Ab/mg NPs (NP-IgG gel) was used as a control. BL, baseline. (A to F) Vagina, (G and H) PBMC, (I and J) rectus, (K and L) inguinal lymph nodes, (M to P) ectocervix. P < 0.05 or P < 0.01 compared with baseline. (A to P) n = 4 for NP-IgG gel–treated group, n = 5 for NP-α4β7 gel–treated group (one of the rhesus macaques, IK06, was excluded because no cells were recovered at the time point of 0 for flow cytometry analysis).

Tables

  • Table 1 Particle size and zeta potential in different media.

    Values represent means ± SD, n = 3.

    NaH2PO4, pH 7.0VFS, pH4.2
    Size (nm)PDIZeta potential
    (mV)
    Size (nm)PDIZeta potential
    (mV)
    NPs231.6 ± 15.00.254−7.29 ± 1.87232.8 ± 6.80.2471.22 ± 1.14
    NPs-α4β7 Ab250.9 ± 3.00.328−0.01 ± 0.03262.5 ± 4.00.1671.68 ± 0.20
  • Table 2 Antibody conjugation efficiency and antibody loading.

    Values represent means ± SD, n = 3.

    Concentration of α4β7
    Ab (mg/ml)
    Ab conjugation
    efficiency
    Ab loading
    (μg Ab/mg NPs)
    0.745.7 ± 1.1%30.5 ± 0.7
    1.432.6 ± 0.5%43.4 ± 0.7
    3.412.3 ± 0.2%41.1 ± 0.7

Stay Connected to Science Advances

Navigate This Article