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

TITLE=Oral Administration of a Shigella 2aT32-Based Vaccine Expressing UreB-HspA Fusion Antigen With and Without Parenteral rUreB-HspA Boost Confers Protection Against Helicobacter pylori in Mice Model

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.894206

DOI=10.3389/fimmu.2022.894206

ISSN=1664-3224

ABSTRACT=<p><italic>Helicobacter pylori</italic> (<italic>H. pylori</italic>) is a gram-negative pathogen classified as a class I carcinogen. The <italic>H. pylori</italic> urease B subunit (UreB) and heat shock protein A (HspA) are two important vaccine candidate antigens. In this study, we evaluated the immunogenicity and immunoprotective effect of the attenuated <italic>Shigella</italic> vector vaccine SH02 expressing the UreB-HspA fusion protein of <italic>H. pylori</italic> in a mouse model. Oral SH02 with or without subcutaneous injection of rUreB-HspA induced antigen-specific serum IgG, mucosal sIgA, and T cells immune response. Subcutaneous injection of the candidate antigen rUreB-HspA enhanced the level of serum antigen-specific IgG antibodies (<italic>p</italic> &lt; 0.0001) and the levels of IgG1/IgG2a/IgG2b subtypes. In addition, injection boost also increased the proportion of spleen antigen-specific CD4+CD154+ T cells (<italic>p</italic> &lt; 0.001), and the proportion of CD4+CD154+ T cells that secrete IFN-γ and IL-17A. Following the <italic>H. pylori</italic> challenge, the levels of <italic>H. pylori</italic> colonization in the two experimental groups (Groups A and B) significantly reduced compared with the control group (<italic>p</italic> &lt; 0.001), indicating that the candidate vaccine yielded a preventive effect of anti-<italic>H.pylori</italic> infection. Compared with the non-subcutaneous booster injection group (Group A), the subcutaneous booster injection group (Group B) exhibited less gastric inflammation, but there was no significant difference in the level of colonization (<italic>p</italic> &gt; 0.05). These results lay a foundation for the development of a vaccine against <italic>H. pylori</italic> and the optimization of immunization methods and procedures to prevent <italic>H. pylori</italic> infection.</p>