Antigenic and conserved peptides from diverse Helicobacter pylori antigens

Abstract

Since the revolutionary finding of Helicobacter pylori as a common bacterial infection, that a high research effort for its eradication has been conducted. Epitope based-vaccine presents advantages over protein-based, as they can be designed to contain epitopes from diverse proteins, therefore, more easily representing the immune-variability of the bacterial population, while minimizing the toxicity associated to some whole proteins. In the present work, an iterative method, to design antigenic and conserved B-epitopes from diverse virulent factors of H. pylori, was established. The method considered the trade-off between epitopes antigenicity and conservation among the bacterial population. For the method validation, five virulent factors from H. pylori were selected. From each virulent factor, two epitopes were predicted, each with twelve residues of aminoacids. The corresponding ten peptides were synthesised and evaluated by enzyme-linked immunosorbent assay using polyclonal antibodies raised against a specific H. pylori strain. All ten peptides were recognised by the antibodies and were consequently antigenic and conserved. This result could strongly contribute to the design of a multivalent epitope-based vaccine, representing the immunogenetic variability within the bacterial population, leading to a sustained and effective immunogenic protection.

A self-assembled trimeric protein vaccine induces protective immunity against Omicron variant

“…To learn the potential impact of the L452R and T478K mutations on the RBD antigenicity, we utilized the Jameson and Wolf algorithm 33 , 34 to calculate their antigenic indices, which could generate surface contour profiles and quantitatively predict protein antigenicity from the amino acid sequence. Bioinformatic analyses of the RBD sequences revealed that both L452R and T478K mutations seem to benefit RBD antigenicity, raising the antigenic index values from −0.45 for L452 to −0.15 for R452 and from 0.45 for T478 to 2.05 for K478, respectively (Fig.…”

Immunoinformatics‐Based Designing of Novel and Potent Multi‐Epitope PSA D15 and Cag11 Immunogens for Helicobacter pylori Immunodiagnostic Assay Development

“…To develop successful multi-epitope antigens, at first, the present study carefully selected immunodominant H. pylori PSA D15 and Cag11 proteins which are the major virulence and invasive factors in H. pylori infection, which deserve to be further explored in terms of immunogenic epitopes [6]. According to [33], identification of the conserved region of PSA D15 and Cag11 antigen of H. pylori strains is a critical step for designing a universal epitope-based biomarker/antigens to all H. pylori strains for immunodiagnostic assay development and vaccine design.…”

How Long Will It Take to Launch an Effective Helicobacter pylori Vaccine for Humans?

“…Many studies have shown that immunity against H. pylori induced by a single antigen does not produce effective protection, and effective immunity against H. pylori infection is often achieved by the combination of various antigens. 197 Therefore, many research groups are committed to developing H. pylori vaccines based on multiple antigens. Epitope-based vaccines are more cost-effective than mixed proteins and can cover more protein targets, so multiepitope vaccines receive more attention.…”