Fig. 7: ART5803 blocks NMDAR internalization induced by patient-derived polyclonal autoantibodies and patients’ sera and CSF in NMDAR-expressing HEK293 cells.

a Using HEK293 cells expressing human NMDAR GluN1 and GluN2B subunits, the NMDAR internalization assay evaluated the effects of antibodies on GluN1 surface expression, measured by flow cytometry. Recovery of surface GluN1 expression after incubation with a patient monoclonal antibody mixture for 18 h, followed by ART5803 co-incubation for an additional 12 h. Data are mean ± SD of n = 2 internal replicates. b Effect of ART5803 (blocking, co-incubation) on Patient 2-6 CSF-like monoclonal antibody mixtures induced internalization for 24 h. Data are mean ± SD of n = 2 internal replicates. c NMDAR binding activity of patients’ sera and CSF samples to HEK293 cells expressing human NMDAR GluN1 and GluN2B subunits, measured by flow cytometry (502 Ab equivalent pseudo-concentration). Each ID correlates to a sera/CSF matched patient. R² and p values were calculated by simple linear regression (n = 6; data presented as mean). Simple linear regression best fit line is solid, and the 95% confidence bands are dotted. Patient #2 was excluded from this graph due to the lack of serum data. CSF = cerebrospinal fluid. d The effect of ART5803 (blocking, co-incubation) on NMDAR internalization induced by patients’ sera and CSF for 20 h. Each graph is titled with a unique patient identifier and is matched between serum and CSF. Serum dilutions of 3% and 10% are indicated by ^ and ^^ respectively. CSF dilutions of 10% and 40% are indicated by * and ** respectively. Red bars indicate no treatment, and blue bars indicate treatment with ART5803. The mean ± SD of n = 2 internal replicates is represented for all samples except for serum #1, which the mean ± SD from n = 2 independent experiments. Source data are provided as a Source Data file.