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

Background: Pseudomonas aeruginosa is an opportunistic pathogen that infects people with immunocompromised defenses like neutropenic, burned, hospitalized, and cystic fibrosis (CF) patients. Objectives: 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. Materials and Methods: 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/ELISAand IL-4 and IFN-y cytokine level assaywas carried out to determine the pattern of immune response (Thi vs. Th2). Specific antibody responses were measured with an optimized in direct ELISA and finally different isotype-specific antibodies including IgGI, IgG2a, IgG2b, IgG3, and IgM was measured with ELISA. Results: 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-y secretion was observed in immunized mice compared with the control group (P= 0.003 and P = 0.006, respectively) with Thi 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). Conclusions: Our results demonstrated that r-fla-A could induce cellular and humoral immune response as proper stimulant of polyisotypic humoral responses.