MOGAD patient autoantibodies induce complement, phagocytosis, and cellular cytotoxicity
Soumya S. Yandamuri, … , Erin E. Longbrake, Kevin C. O’Connor
Soumya S. Yandamuri, … , Erin E. Longbrake, Kevin C. O’Connor
Published April 25, 2023
Citation Information: JCI Insight. 2023;8(11):e165373. https://doi.org/10.1172/jci.insight.165373.
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Research Article Neuroscience

MOGAD patient autoantibodies induce complement, phagocytosis, and cellular cytotoxicity

Abstract

Myelin oligodendrocyte glycoprotein (MOG) antibody–associated disease (MOGAD) is an inflammatory demyelinating CNS condition characterized by the presence of MOG autoantibodies. We sought to investigate whether human MOG autoantibodies are capable of mediating damage to MOG-expressing cells through multiple mechanisms. We developed high-throughput assays to measure complement activity (CA), complement-dependent cytotoxicity (CDC), antibody-dependent cellular phagocytosis (ADCP), and antibody-dependent cellular cytotoxicity (ADCC) of live MOG-expressing cells. MOGAD patient sera effectively mediate all of these effector functions. Our collective analyses reveal that (a) cytotoxicity is not incumbent on MOG autoantibody quantity alone; (b) engagement of effector functions by MOGAD patient serum is bimodal, with some sera exhibiting cytotoxic capacity while others did not; (c) the magnitude of CDC and ADCP is elevated closer to relapse, while MOG-IgG binding is not; and (d) all IgG subclasses can damage MOG-expressing cells. Histopathology from a representative MOGAD case revealed congruence between lesion histology and serum CDC and ADCP, and we identified NK cells, mediators of ADCC, in the cerebrospinal fluid of relapsing patients with MOGAD. Thus, MOGAD-derived autoantibodies are cytotoxic to MOG-expressing cells through multiple mechanisms, and assays quantifying CDC and ADCP may prove to be effective tools for predicting risk of future relapses.

Authors

Soumya S. Yandamuri, Beata Filipek, Abeer H. Obaid, Nikhil Lele, Joshua M. Thurman, Naila Makhani, Richard J. Nowak, Yong Guo, Claudia F. Lucchinetti, Eoin P. Flanagan, Erin E. Longbrake, Kevin C. O’Connor

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Figure 3

MOGAD patient serum induces CDC and ADCP of live MOG-expressing cells while HD, MG, and NMOSD serum do not.(A–L)

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MOGAD patient serum induces CDC and ADCP of live MOG-expressing cells wh...
HI serum from patients with MOGAD (nCDC = 17, nADCP = 19), MG (nCDC = 13, nADCP = 12), and NMOSD (nCDC = 15, nADCP = 10) and HD (nCDC = 11, nADCP = 7) were evaluated for CDC (A–I) and ADCP induction (J–L), normalized to that of media alone (no antibodies or donor serum). (A) Representative histograms depict MAC deposition on MOG+ cells by MOGAD versus HD serum in the CDC assay. (B and C) Comparative MAC formation on (B) MOG+ and (C) MOG– cells by condition. (D) Representative histogram depicts dead MOG+ cells by MOGAD versus HD serum. (E and F) Comparative dead (E) MOG+ and (F) MOG– cells by condition. (G) Resultant frequency of MOG+ cells out of total HEK cells. (H) Comparison of frequency of MAC formation versus death of MOG+ cells per sample. (I) Linear regression of MOGAD samples only (goodness of fit, R2, and significance of nonzero slope, P value, shown on graph). (J) Representative dot plot depicts frequency of phagocytosing macrophages (GFP+) upon incubation with MOGAD versus HD serum in ADCP assay. (K and L) Frequency of (K) phagocytosing macrophages and (L) MOG+ cells out of total HEK cells by condition. Each dot represents a patient (average of duplicates), normalized to media-only control, and bars depict mean ± SEM. Normality test followed by Kruskal-Wallis for B (P = 2.3 × 10–4), C (P = 0.22), E (P = 5.6 × 10–3), and K (P = 1.4 × 10–5) and 1-way ANOVA for G (P = 1.2 × 10–5) and L (P = 1.1 × 10–5). For P ≤ 0.05, multiple comparisons were corrected with FDR of 0.05 and depicted on graph (*P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.005, #P ≤ 0.0005, ##P ≤ 0.0001, ###P ≤ 0.00005, +P ≤ 0.00001).