Fig. 2.
OMV immunization elicits immune responses to multiple ETEC antigens. (a) Immunoblots obtained using pooled sera from mice immunized with vesicles prepared from jf1412. Control, pooled sera from vehicle control-immunized mice. Immunoblots of vesicle preparations are shown on the left, and immunoblots of individual recombinant antigens previously identified in vesicles appear on the right. (b) Kinetic ELISA data for three OMV-associated antigens, EtpA, CexE, and LT. Each recombinant antigen was tested with control (open symbols) and immune (closed symbols) antisera (at a 1:64 dilution) from 10 mice. (c) Fecal antibody levels assessed by kinetic ELISA determinations using OMV-associated antigens are shown for PBS control mice (open symbols) and OMV-immunized mice (closed symbols). Data were obtained with undiluted stool filtrates. Kinetic ELISA data were obtained at 1-min intervals, and the Vmax slope was obtained 15 min after the addition of substrate. P values reflect Mann-Whitney testing (two-tailed) to compare values from immune and nonimmune groups for each antigen. Dashed horizontal lines are geometric mean values.