A human-derived protein SBP (HBsAg-binding protein) can bind to hepatitis B virus surface antigen (HBsAg) and enhance the immune response to hepatitis B virus (HBV) vaccine.
A high titer of antibody to HBsAg (Hepatitis B virus surface antigen) (anti-HBs) is a requisite for the prevention of HB (Hepatitis B), and adjuvants generally play a great role in eliciting special anti-HBs to HB vaccine. However, adjuvants still need to be improved because of their shortages such as unremarkable efficacy, undesirable side effect or poor security. In this study, we used HBsAg separated from HB patient sera to screen a human liver cDNA expression library, and found a novel HBsAg-binding protein (SBP), which is located at the human chromosome 14q32.33 and is similar to human IgG heavy chain in structure. Western blot demonstrated that SBP existed in both healthy human sera and HB patient sera. Furthermore, SBP could bind to HBsAg by its N-terminal domain. Notably, we confirmed that SBP could promote dendritic cells (DC) to phagocytize HBsAg more effectively and enhance the immunogenicity of HB vaccine, when SBP was mixed proportionally with HBsAg and the resulting mixture was infused into mice. These results suggest that SBP could be developed into a safe and promising adjuvant of HB vaccine.
Laboratory of Molecular Immunology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, China.
Chongwen
C
Zhang
Li
L
Gong
Yuanyuan
Y
Chen
Xiaohua
X
Wang
Sibo
S
Zhu
Ding
D
Li
Yun
Y
Pang
Yue
Y
Yin
Xi
X
Liu
Naishuo
N
Zhu
D000276:Adjuvants, Immunologic; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D015723:Gene Library; D006509:Hepatitis B / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000276:immunology*; D017325:Hepatitis B Vaccines / Q000276:immunology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D010587:Phagocytosis / Q000276:immunology; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D011991:Receptors, Virus / Q000737:chemistry / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000276:Adjuvants, Immunologic; D002352:Carrier Proteins; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D011991:Receptors, Virus