Pseudomonas aeruginosa Recombinant Flagellin Induced Poly-Isotypic Humoral Immune Responses in the Balb/C Mice

Pseudomonas aeruginosa is an opportunistic pathogen that infects people with immunocompromised defenses like neutropenic, burned, hospitalized, and cystic fibrosis (CF) patients.. The main aim of this study was to explore the possibility of the recombinant type A flagellin (r-fla-A) in combination of Montanide ISA 70 as a candidate vaccine to promote the humoral and cellular immune responses against r-fla-A.. Recombinant flagellin was prepared in Montanide ISA 70 adjuvant; Mice were divided into two groups one of six. The lymphocyte proliferation assay was performed with Brdu/ELISA and IL-4 and IFN-γ cytokine level assay was carried out to determine the pattern of immune response (Th1 vs. Th2). Specific antibody responses were measured with an optimized in direct ELISA and finally different isotype-specific antibodies including IgG1, IgG2a, IgG2b, IgG3, and IgM was measured with ELISA.. Immunized mice with adjuvanted flagellin showed a considerably increased lymphocyte proliferation compared with the control group (P = 0.004). High level of IL-4 and IFN-γ secretion was observed in immunized mice compared with the control group (P = 0.003 and P = 0.006, respectively) with Th1 profile. In addition to the strong antibody-mediated immune response, we found that immunization of mice with r-fla-A induces specific IgG1, IgG2a, IgG2b, IgG3 and IgM antibodies that indicates a statistically significant difference with the control group (P = 0.003, P = 0.004, P = 0.004, P = 0.006 and P = 0.004 respectively).. Our results demonstrated that r-fla-A could induce cellular and humoral immune response as proper stimulant of poly-isotypic humoral responses..