Figure 1.

MDA5(+) samples from plasma exchange (PLEX) show reactivity to helicase-bearing MDA5 constructs. (A) Schematic representation of the MDA5 protein (side and top view) and the MDA5 protein constructs. (B) ELISA to assess the reactivity of MDA5(+) samples from PLEX (n = 8, upper panel) and the corresponding purified IgG (n = 8, lower panel) against conformational epitopes on the MDA5 constructs A–H and the negative control (RIG-I). (C) Western blot analysis to assess the reactivity of purified IgGs against linearized epitopes on the MDA5 constructs A–H and RIG-I (n = 4 representative blots). In (B), statistical analysis was performed using Kruskal–Wallis test with Dunn’s correction: *P-value < 0.05, ***P-value < 0.001, ^nsP-value > 0.05. Dots represent individual subjects, lines/bars represent median (± interquartile range). MDA5: melanoma differentiation–associated protein 5; OD: optical density; CARD: N-terminal caspase activation and recruitment domains; Hel: helicase domains 1/2i/2; P: pincer; CTD: C-terminal domain; RIG-I: retinoic acid–inducible protein I