title: Conjugation of PEG-hexadecane markedly increases the immunogenicity of pneumococcal polysaccharide conjugate vaccine.
abstract: Streptococcus pneumoniae is a serious Gram-positive pathogen that can lead to an invasive pneumococcal disease with high mortality rate. Pneumococcal capsular polysaccharide (PS) is a key virulence determinant and its immunogenicity can be increased by conjugation with a carrier protein. However, the PS-specific cellular and humoral immunity of pneumococcal conjugate vaccine needs further improvement. Hexadecane (HD) is an element of lipid that decorates the surface of nearly all microbial classes. Polyethylene glycol (PEG)-HD conjugate (PEG-HD) is soluble and can act as an adjuvant. In the present study, a novel pneumococcal polysaccharide conjugate vaccine was prepared by conjugation of tetanus toxoid (TT) portion of PS-TT conjugate (PS-TT) with PEG-HD. As compared with PS-TT, conjugation with PEG-HD led to an 8.0-fold increase in the PS-specific IgG titers. Conjugation with PEG-HD also gave rise to 34.9-, 3.6- and 7.7-fold increase in the IFN-γ, TNF-α and IL-5 levels, respectively. Thus, the conjugated PEG-HD has a stimulatory adjuvant activity to potentiate a robust humoral and cellular immunity. Our proposed conjugate was expected to act as an effective pneumococcal conjugate vaccine for prevention of S. pneumoniae infections.
authors.affiliation: College of Pharmacy, University of Guizhou, Guiyang 550025, Guizhou Province, China; State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Weili
authors.initials: W
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Shaoyang
authors.initials: S
authors.lastname: Ji
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Shen
authors.affiliation: College of Pharmacy, University of Guizhou, Guiyang 550025, Guizhou Province, China.
authors.forename: Aijuan
authors.initials: A
authors.lastname: Tan
authors.affiliation: State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: thu@ipe.ac.cn.
authors.forename: Tao
authors.initials: T
authors.lastname: Hu
mesh_terms: D000276:Adjuvants, Immunologic / Q000378:metabolism*; D000473:Alkanes / Q000378:metabolism*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D016207:Cytokines / Q000378:metabolism; D005260:Female; D007074:Immunoglobulin G / Q000097:blood; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008807:Mice, Inbred BALB C; D022242:Pneumococcal Vaccines / Q000276:immunology*; D011092:Polyethylene Glycols / Q000378:metabolism*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D013745:Tetanus Toxoid / Q000378:metabolism; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000473:Alkanes; D000907:Antibodies, Bacterial; D016207:Cytokines; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D013745:Tetanus Toxoid; D018074:Vaccines, Conjugate; D011092:Polyethylene Glycols; C007932:n-hexadecane
keywords: Adjuvant; Hexadecane; Polyethylene glycol; Streptococcus pneumoniae