Identification of B-Cell Epitopes of HspA from Helicobacter pylori and Detection of Epitope Antibody Profiles in Naturally Infected Persons.

Xin Zhang,Qing Guan,Chunjie Liu,Haoxia Tao,Shuli Sang,Yanchun Wang

doi:10.3390/vaccines10010065

Xin Zhang, Qing Guan + Show 4 more

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https://doi.org/10.3390/vaccines10010065

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Abstract

Helicobacter pylori (H. pylori), heat-shock protein A (HspA), is a bacterial heat-shock chaperone that serves as a nickel ion scavenging protein. Ni2+ is an important co-factor required for the maturation and enzymatic activity of H. pylori urease and [NiFe] hydrogenase, both of which are key virulence factors for pathogen survival and colonization. HspA is an important target molecule for the diagnosis, treatment, and immune prevention of H. pylori. In this work, HspA was truncated into five fragments to determine the location of an antigen immunodominant peptide. A series of overlapping, truncated 11-amino-acid peptides in immunodominant peptide fragments were synthesized chemically and screened by ELISA. The immunogenicity and antigenicity of the screened epitope peptides were verified by ELISA, Western blot, and lymphocyte proliferation tests. Two novel B-cell epitopes were identified, covering amino acids 2–31 of HspA, which are HP11 (2–12; KFQPLGERVLV) and HP19 (18–28; ENKTSSGIIIP). The antiserum obtained from HP11-KLH and HP19-KLH immunized mice can bind to naive HspA in H. pylori SS2000, rHspA expressed in E. coli, and the corresponding GST fusion peptide. Among HspA seropositive persons, the seropositive rates of HP11 and HP19 were 21.4% and 33.3%, respectively. Both of the B-cell epitopes of HspA are highly conserved epitopes with good antigenicity and immunogenicity.

Highlights

Published: 31 December 2021Helicobacter pylori (H. pylori), a spiral-shaped, microaerophilic, Gram-negative bacterium that colonizes the stomach of nearly half of the world’s population, has been classified as a group I carcinogen by the International Agency for Research on Cancer (IARC)
Our findings provide a basis for further study on the role of heat-shock protein A (HspA) in immune response and immune prevention caused by H. pylori infection
It was found that the originally designed fourth peptide was difficult to chemically syntheserious hydrophobicity, and finallyand it was shortened to 24 amino

Summary

Introduction

Helicobacter pylori (H. pylori), a spiral-shaped, microaerophilic, Gram-negative bacterium that colonizes the stomach of nearly half of the world’s population, has been classified as a group I carcinogen by the International Agency for Research on Cancer (IARC). H. pylori infection is usually acquired in childhood and, if it is not cured, can cause lifelong infection [4]. The eradication rate of H. pylori has a downward trend in the world, along with a rapid increase in clarithromycin resistance in many countries during the past decade [6]. In addition to increasing reports of antibiotic-resistant strains, high treatment costs, poor drug compliance, and a high rate of infection recurrence are the main reasons for the failure of large-scale control of H. pylori infection. Research on immune response and immune protection mechanisms

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