Fig. 8: Activation of neutrophils by IgG from volunteers immunized with SumayaVac-1. | npj Vaccines

Fig. 8: Activation of neutrophils by IgG from volunteers immunized with SumayaVac-1.

From: Immunization with full-length Plasmodium falciparum merozoite surface protein 1 is safe and elicits functional cytophilic antibodies in a randomized first-in-human trial

Fig. 8

P. falciparum merozoites from the a 3D7 strain expressing MSP1-D or the b FCB1 strain expressing MSP1-F and neutrophils were incubated in the presence of purified IgG from volunteers immunized three times with SumayaVac-1 (collected at days 0 and 85). Opsonized merozoites activated neutrophils to produce a respiratory burst, which was quantitatively expressed in terms of an ADRB index. Each data point represents the mean ADRB Index of at least two independent experiments each performed in duplicates from one volunteer. Black marks indicate the geometric mean values of the corresponding cohort. Statistical significance was assessed using paired t-test (between day 0 and day 85) and the Kruskal–Wallis one-way ANOVA on ranks (between different dosing groups). ADRB activities for purified IgG from semi-immune adults from Nouna, Burkina Faso (n = 11), and from Kenya (pooled IgG) are indicated as reference. c Correlation between the net ADRB index (corrected for the background activity at day 0) and the α-MSP1-D titer (at day 85) (correlation coefficient, 0.545; p = 0.006, according to Spearman rank order correlation). Each data point represents the results from one volunteer (n = 24).

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