Fig. 4.

Detection of MAL expression on EV by pETX-647 binding. A Gating strategy for identification of pETX/MAL+ EV. SEC isolated EV were probed with pETX-647 or pETX-647 pretreated with a neutralizing antibody (pETX-647 + AB) which inhibits pETX-647 binding to MAL as a negative control. Unstained EV were used as an additional control. EV of appropriate size were analyzed for pETX-647 binding. B Histogram representation of pETX-647 fluorescence when EV are stained with pETX-647 or pETX-647 pretreated with the neutralizing antibody (pETX-647 + AB). C Enumeration of total EV identified from the size gate per μL of plasma for different patient groups including HC, active RRMS patients not receiving DMT (Active), stable RRMS patients not receiving DMT (Stable), or stable RRMS patients receiving natalizumab (NTZ) or ocrelizumab (OCZ). D Enumeration of pETX/MAL+ EV concentrations from indicated patient groups. Results are displayed as box and whisker plots with each individual patient represented as a dot. * p ≤ 0.05, ** p ≤ 0.01 determined by one-way ANOVA with post-hoc Tukey HSD Test