Protective Immunity against Listeria monocytogenes in Rats,Provided by HCl- and NaOH-Induced Listeria monocytogenes Bacterial Ghosts (LMGs) as Vaccine Candidates |
| |
Authors: | Seongmi Ji Eun Sun Moon Han Byul Noh Hyun Jung Park Seongdae Kim Sung Oh Nagarajan Vinod Chang Won Choi Kilhan Kwak |
| |
Affiliation: | 1.Department of Biology, Graduate School, Pai Chai University, Daejeon 35345, Korea; (S.J.); (E.S.M.); (H.B.N.); (H.J.P.); (S.K.); (S.O.); (N.V.);2.Animal Health Institute of Jeollabukdo Western Branch, Jeonbuk Provincial Government, 18-4, Jangsu-gun 55632, Korea; |
| |
Abstract: | Listeria monocytogenes (Lm) bacterial ghosts (LMGs) were produced by the minimum inhibitory concentration (MIC) of HCl, H2SO4, and NaOH. Acid and alkali effects on the LMGs were compared by in vitro and in vivo analyses. Scanning electron microscope showed that all chemicals form lysis pores on the Lm cell envelopes. Real-time qPCR revealed a complete absence of genomic DNA in HCl- and H2SO4-induced LMGs but not in NaOH-induced LMGs. HCl-, H2SO4- and NaOH-induced LMGs showed weaker or missing protein bands on SDS-PAGE gel when compared to wild-type Lm. Murine macrophages exposed to the HCl-induced LMGs showed higher cell viability than those exposed to NaOH-induced LMGs or wild-type Lm. The maximum level of cytokine expression (TNF-α, iNOS, IFN-γ, and IL-10 mRNA) was observed in the macrophages exposed to NaOH-induced LMGs, while that of IL-1β mRNA was observed in the macrophages exposed to HCl-induced LMGs. To investigate LMGs as a vaccine candidate, mice were divided into PBS buffer-injected, HCl- and NaOH-induced LMGs immunized groups. Mice vaccinated with HCl- and NOH-induced LMGs, respectively, significantly increased in specific IgG antibodies, bactericidal activities of serum, and CD4+ and CD8+ T-cell population. Antigenic Lm proteins reacted with antisera against HCl- and NOH-induced LMGs, respectively. Bacterial loads in HCl- and NaOH-induced LMGs immunized mice were significantly lower than PBS-injected mice after virulent Lm challenges. It suggested that vaccination with LMGs induces both humoral and cell-mediated immune responses and protects against virulent challenges. |
| |
Keywords: | Listeria monocytogenes bacterial ghosts HCl-induced Listeria monocytogenes ghosts NaOH-induced Listeria monocytogenes ghosts cytotoxicity pro- and anti-inflammatory mediators vaccine candidate humoral immunity cell-mediated immunity protection against virulent challenge |
|
|