Fig. 2: Afucosylated anti-HIV-1 bNAbs potentiate activation and degranulation of NK cells.

a Schematic representation of the plate-based NK cell activation assay. Expression of CD107, CD16 and IFNγ was analyzed after incubating NK cells with HIV-1 Env bound antibodies. NK cells were isolated from healthy donors using a negative selection kit (b) CD107+IFNγ+ double-positive NK cells, and % CD16 shedding is plotted for NK cells after incubation with a serial dilution of fucosylated or afucosylated anti-HIV-1 Abs 2G12, N6, PGT151 and PGDM1400. The dotted line indicates the Ab concentration (5μg/ml) that was used to analyze NK cell activation of all other anti-HIV-1 Abs. These triplicate measurements + standard deviation at 5μg/ml are plotted in the bar graphs next to the titration curves in which fucosylated Abs are depicted in dark gray and afucosylated Abs in light gray. Statistical differences between fucosylated and afucosylated bNAbs were determined using an ordinary one way Anova with a Šídák's multiple comparisons test and significant differences are indicated with asterisks. *p < 0.05, **p < 0.01, ***p < 0.001. c Expression of TIGIT and PD-1 on NK cells from PWH (red triangles) and HIV-1 negative donors (black dots) prior to stimulation and percentage CD107+IFNγ+CD3− cells in response to fucosylated or afucosylated N6 Ab for five PWH and five uninfected donors. Statistical differences between fucosylated and afucosylated bNAbs were determined using a Wilcoxon matched-pairs signed rank test and significant differences are indicated with asterisks. *p < 0.05, **p < 0.01, ***p < 0.001.