Effect of the cagW-based gene vaccine on the immunologic properties of BALB/c mouse: an efficient candidate for Helicobacter pylori DNA vaccine

Abstract

Background: Helicobacter pylori (H. pylori) infect more than half of the world population, and they cause different serious diseases such as gastric carcinomas. This study aims to design a vaccine on the basis of cagW against H. pylori infection. After pcDNA3.1 (+)-cagW-CS-NPs complex is produced, it will be administered into the muscles of healthy BALB/c mice in order to study the effect of this DNA vaccine on the interleukin status of mice, representing its effect on the immune system. After that, the results will be compared with the control groups comprising the administration of cagW-pCDNA3.1 (+) vaccine, the administration of chitosan and the administration of PBS in the muscles of mice. Methods: The cagW gene of H. pylori was amplified by employing PCR, whose product was then cloned into the pcDNA3.1 (+) vector, and this cloning was confirmed by PCR and BamHI/EcoRV restriction enzyme digestion. CagW gene DNA vaccine was encapsulated in chitosan nanoparticles (pcDNA3.1 (+)-cagW-CS-NPs) using a complex coacervation method. The stability and in vitro expression of chitosan nanoparticles were studied by DNase I digestion and transfection, and the immune responses elicited in specific pathogen-free (SPF) mice by the pcDNA3.1 (+)-cagW-CS-NPs were evaluated. Apart from that, the protective potential pcDNA3.1 (+)-cagW-CS-NPs was evaluated by challenging with H. pylori. Results: The pcDNA3.1 (+)-cagW-CS-NPs comprises cagW gene of H. pylori that is encapsulated in chitosan nanoparticles, produced with good morphology, high stability, a mean diameter of 117.7 nm, and a zeta potential of + 5.64 mV. Moreover, it was confirmed that chitosan encapsulation protects the DNA plasmid from DNase I digestion, and the immunofluorescence assay showed that the cagW gene could express in HDF cells and maintain good bioactivity at the same time. In comparison to the mice immunized with the control plasmid, in vivo immunization revealed that mice immunized with pcDNA3.1 (+)-cagW-NPs showed better immune responses and prolonged release of the plasmid DNA. Conclusions: This research proves chitosan-DNA nanoparticles as potent immunization candidates against H. pylori infection and paves the way for further developments in novel vaccines encapsulated in chitosan nanoparticles.

Biomaterials for Helicobacter pylori therapy: therapeutic potential and future perspectives

“…Polymers are also used as delivery vehicles for mRNA, DNA, and/or adjuvants in vaccines in various forms and morphologies because of their excellent stability. 102 For example, Chehelgerdi et al prepared a cagW‑based DNA vaccine loaded with chitosan nanoparticles; 103 upon injecting mice with this vaccine, the expression of cagW increased on the 7th day and then gradually decreased, reaching a minimum on the 45th day. Furthermore, they found that vaccination significantly increases cellular immunity.…”

“…This suggested that the vaccine exhibited a protective effect against H. pylori in mice. 103 In addition to chitosan, polymers such as HP55 (a special type of hydroxypropyl methylcellulose phthalate)/D and poly(lactic-co-glycolic acid) (PLGA) have also been used as delivery systems for vaccines. 104 For example, Tan et al designed an oral dual-antigen epitope and dual-adjuvant vaccine based on the urease of H. pylori and cholera toxin B subunits and delivered it with HP55/PLGA nanoparticles.…”

Secretory System Components as Potential Prophylactic Targets for Bacterial Pathogens

“…In the first approach based on type IV secretion system antigens, Chehelgerdi and Doosti [122] used CagW protein as a probable functional analog of the structural VirB6 protein from the type IV secretion system. In the plasmid-based DNA vaccine strategy, the gene coding CagW protein was delivered in pcDNA-3.1 at 100 µg/mouse of plasmid encapsulated or not in chitosan nanoparticles into mice intramuscularly 5 times within 45 days.…”

Immunoinformatic prediction of potential immunodominant epitopes from cagW in order to investigate protection against Helicobacter pylori infection based on experimental consequences

“…Helicobacter pylori ( H. pylori ) is a bacteria that may cause a variety of illnesses, including mucosal lymph tissue, peptic ulcers, and stomach cancer (Chehelgerdi & Doosti, 2020 ; Lai et al, 2023 ). H. pylori is mostly connected with stomach infections, but it has also been linked to other illnesses (Kargar et al, 2010 ).…”