Recombinant outer membrane protein C of Aeromonas hydrophila elicits mixed immune response and generates agglutinating antibodies

Abstract

Aeromonas hydrophila is a gram-negative fish pathogenic bacterium, also responsible for causing opportunistic pathological conditions in humans. It causes a number of diseases in fish due to which the fish industry incurs huge economic losses annually. Due to problems of antibiotic resistance, and the rapidity with which the infection spreads among fishes, vaccination remains the most effective strategy to combat this infection in fish populations. Among various virulence factors associated with bacterial virulence, outer membrane proteins have been widely evaluated for their vaccine potential owing to their surface exposure and related role in pathogenicity. In the present study, we have investigated the immunogenic potential of a non-specific porin, outer membrane protein C (OmpC) whose expression is regulated by the two-component regulatory system and plays a major role in the survival of A. hydrophila under different osmolaric conditions. The full-length gene (~1 kb) encoding OmpC of A. hydrophila was cloned, characterized and expressed in E. coli. High yield (~112 mg/L at shake flask level) of the recombinant OmpC (rOmpC) (~40 kDa) of A. hydrophila was obtained upon purification from inclusion bodies using Ni(2+)-NTA affinity chromatography. Immunization with purified rOmpC in murine model generated high endpoint (>1:40,000) titers. IgG isotyping, ELISA and ELISPOT assay indicated mixed immune response with a TH2 bias. Also, the anti-rOmpC antibodies were able to agglutinate A. hydrophila in vitro and exhibited specific cross-reactivity with different Aeromonas strains, which will facilitate easy detection of different Aeromonas isolates in infected samples. Taken together, these data clearly indicate that rOmpC could serve as an effective vaccine against different strains of Aeromonas, a highly heterogenous group of bacteria.

How does temperature influences the development of lactococcosis? Transcriptomic and immunoproteomic in vitro approaches

“…; Yadav et al . ), the knowledge of immunogenic antigens of L. garvieae might contribute to explain the differences in virulence among strains and these molecules could be used as potential markers for developing effective vaccines against this pathogen (Shin et al . , ).…”

“…ncbi.nlm.nih.gov/genome/genomes/699) have contributed to the identification of different genes potentially implicated in its virulence (Morita et al 2011;Miyauchi et al 2012). Also, as virulence factors are usually strongly immunogenic (Chitlaru et al 2007;Yadav et al 2016), the knowledge of immunogenic antigens of L. garvieae might contribute to explain the differences in virulence among strains and these molecules could be used as potential markers for developing effective vaccines against this pathogen (Shin et al 2007(Shin et al , 2009. In this sense, temperature must be taken in consideration, as it can affect the L. garvieae antigenic profiles obtained due to the changes in gene expression (Aguado-Urda et al 2013).…”

Analysis of virulence and immunogenic factors in Aeromonas hydrophila: Towards the development of live vaccines

“…In addition, two recombinant extracellular proteases (epr2 and epr3) of the A. hydrophila strain J‐1 conferred significant protection against infection to Parabramis pekinensis (Wu et al., 2012). Outer membrane proteins (OMPs), including OmpC (Yadav, Meena, Sharma, & Dixit, 2016), OmpA1 (Abdelhamed et al., 2017; Nayak, 2020) and OmpW (Dubey et al., 2016; Zeng et al., 2020), could serve as an effective vaccine against different strains of Aeromonas . Therefore, the virulence factors of A. hydrophila might be good potential candidates for vaccine development.…”

Effects Of Orally Administered Recombinant Lactobacillus Casei Expressing HN Protein On Early Growth Performance, Intestinal Health And Protection Against NDV Challenge In Chickens

“…The jejunum were infused with 0.5 mL phosphatebuffered saline (PBS); pH 7.4, containing 0.1% bovine serum albumin and aprotinin), washed three times, and centrifuged at 2000 rpm at 4 °C for 15 min to collect the supernatant. Commercial ELISA kits for determining secretory immunoglobulin A (SIgA) from jejunal lavage uid, serum interleukin (IL-2) and interferon (IFN-γ) from chickens (Senbeijia, Nanjing, China) were used to determine the NDV antibody levels and cytokine production [21].…”