title: Immunization with Streptococcal Heme Binding Protein (Shp) Protects Mice Against Group A Streptococcus Infection.
abstract: Streptococcal heme binding protein (Shp) is a surface protein of the heme acquisition system that is an essential iron nutrient in Group A Streptococcus (GAS). Here, we tested whether Shp immunization protects mice from subcutaneous infection. Mice were immunized subcutaneously with recombinant Shp and then challenged with GAS. The protective effects against GAS challenge were evaluated two weeks after the last immunization. Immunization with Shp elicited a robust IgG response, resulting in high anti-Shp IgG titers in the serum. Immunized mice had a higher survival rate and smaller skin lesions than adjuvant control mice. Furthermore, immunized mice had lower GAS numbers at the skin lesions and in the liver, spleen and lung. Histological analysis with Gram staining showed that GAS invaded the surrounding area of the inoculation sites in the skin in control mice, but not in immunized mice. Thus, Shp immunization enhances GAS clearance and reduces GAS skin invasion and systemic dissemination. These findings indicate that Shp is a protective antigen.
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China.
authors.forename: Yingli
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China.
authors.forename: Yuanmeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Cai
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Meng
authors.affiliation: Department of Physiology, the college of Basic, Medical Sciences, Harbin Medical University, Harbin, China. dzhuhui@aliyun.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins / Q000235:genetics / Q000276:immunology*; D005260:Female; D006418:Heme / Q000276:immunology; D006801:Humans; D007114:Immunization; D051379:Mice; D013290:Streptococcal Infections / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D006418:Heme
keywords: Group A Streptococcus; Heme Acquisition; Immunization; Shp; Streptococcus Pyogenes; Vaccine