Figure 4. Impact of human and mouse sPLA₂s on erythrocyte MPs.

(A) MPs from human erythrocytes were incubated for 1 and 6 hours at 37°c in absence or in presence of indicated concentrations of human recombinant sPLA₂ IIA, V, X, or 1µg/ml of the inactive mutant V H48Q. Fluorochrome-conjugated antibodies directed against CD235a and fluorochrome-conjugated annexin-V were used to assess the quantities of CD235a⁺ MPs (left panel), of annexin-V⁺ MPs (right panel) and were compared to the untreated conditions (dotted line). Data are mean ± SEM of 5 independent experiments presented as % of untreated (control) (B) MPs from mouse erythrocytes were incubated 1 and 6 hours at 37°c, in absence or in presence of indicated concentrations of mouse recombinant sPLA₂ IIA, V, X, or 1µg/ml of the inactive mutant X H48Q. Fluorochrome-conjugated antibodies directed against TER 119 and fluorochrome-conjugated annexin-V were used to determine the concentrations of TER 119⁺ MPs (left panel) and annexin-V⁺ MPs (right panel) and then compared to the untreated conditions (dotted line). Data are mean ± SEM of 5 independent experiments presented as % of untreated (control). * P< .05; # P< .01; § P< .001.