Fig. 4.

Flow cytometry analysis on wild-type (WT) and mutant meningococcal and gonococcal strains. Murine antisera from three independent immunizations with M2 rT-Nm-MIP-Liposomes were reacted against MIP on the surface of (A) MC58, (D) P9-17 and (F) FA1090 WT strains, or against (C) rT-Nm-MIP on MC58 engineered to express constitutively the truncated protein. Murine antisera from three independent immunizations against M2 rT-Nm-MIP-Liposomes + MPLA were reacted against MIP on the surface of (H) MC58, (K) P9-17 and (M) FA1090 WT strains, or against (J) rT-Nm-MIP on MC58 engineered to express constitutively the truncated protein. The pink area shows no reactivity of the meningococcal or gonococcal strains with murine sham-immunised serum (1/10). The green, orange and blue areas show the significant FACS reactivity of murine antisera (1/10) to M2 rT-Nm-MIP-Liposomes (batches 1, 2 and 3) or M2 rT-Nm-MIP-Liposomes + MPLA (batches 1, 2 and 3) respectively, with MC58, P9-17 and FA1090 WT strains, and with complemented MC58 strain. All antisera were non-reactive against the corresponding MC58 (B, I), P9-17 (E, L) or FA1090 (G, N) nm-mip isogenic knock-out strains. The numbers within each panel refer to the percentage of bacterial populations that were FITC-positive. The asterisks (*) denote the significant (P < 0.05) and right-shifted increases in FITC-fluorescence recorded events, using a two sample t-Test to compare mean fluorescence values of test murine antisera against sham-immunised murine sera. Data are representative of n = 2 experiments. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)