Fig. 8. Anti-Aβ protects neurons by keeping Aβ soluble in supernatant and antibody effector function is not required.

a, b iPSC neurons and astrocytes treated with 5 μM sAβ42s followed by serial dilutions of anti-gD and anti-Aβ antibodies with IgG1 and LALAPG backbones with and without iPSC microglia. Results for dendrite protection (MAP2 area) (a) and synapse protection (synapsin count) (b) were analyzed via IC50 curve fitting using Prism software. Microglia provide baseline protection as shown by an upward shift in the anti-gD graph when microglia are added (gD IgG1 alone, blue; gD IgG1 + microglia, dark blue). Anti-Aβ antibody backbones protect dendrites and synapses similarly without microglia (Anti-Aβ IgG1, red; Anti-Aβ LALAPG, green) and with microglia (Anti-Aβ IgG1, dark red; Anti-Aβ LALAPG, dark green). c, d Neuron, astrocyte, microglia triculture treated with 5 μM sAβ42s (solid lines) and pro-inflammatory cytokines (dashed lines), then serial dilutions of gD antibody (black lines) and anti-Aβ antibody (red lines) were added. c Basal dendrite protection (MAP2 area) is lost in a neuroinflammatory environment, and anti-Aβ shows dose-dependent efficacy. d Plaque formation (Methoxy-X04 total intensity) increases in pro-inflammatory conditions, however, anti-Aβ shows similar plaque reduction. e iPSC microglia (red) were treated with 5 sAβ42s and serial dilutions of anti-Aβ antibody; no cells wells were used as control (blue). The supernatant was collected and anti-Aβ ELISA was performed to measure total Aβ concentration. Anti-Aβ antibody treatment increases soluble Aβ species present in the culture supernatant. f Summary of sequential events in the iPSC AD model. Data are presented as mean values +/− SEM and n = 4 wells. Two-way ANOVA with Tukey’s multiple comparisons test.