Phage display creates innovative applications to combat hepatitis B virus

Table 1 Phage display in vaccine discovery

Strategy	Phage (carrier)	Vector (target)	Epitope/mimotope/gene	Vaccination	Results	Ref.
Display of immunogens on phage particles	T7 (10B)	T7 Select 415-B	“a” determinant of HBsAg (residues 111-156)	Rabbit (subcutaneous) Freund’s complete adjuvant	Anti-HBsAg antibody induced	Tan et al[78]
	M13 (pVIII)	pC89 with helper phage VASM13	HBsAg28-39	Mice (intradermal and intraperitoneal) no adjuvant added	MHC class I restricted HBsAg specific CTL response	Wan et al[40]
	M13 (pIII)	pCANTAB5E with helper phage M13KO7	PreS1	NA	NA	Kok et al[41]
	M13 (pIII)	pCANTAB5E with helper phage M13KO7	HBcAg	Mice (intraperitoneal) incomplete Freund’s adjuvant	Anti-HBcAg antibody induced	Bahadir et al[42]
Identification of epitope or mimotope mimics	M13 nonapeptide library (pVIII)	(Selected from HBV-infected sera)	Φ13 CRTCAHPGEHA Φ17 CIPFYLSAPQC Φ30 CGPFFLSPTSC Φ41 CGPFFLAASVC	Mice (intraperitoneal) no adjuvant added	Anti-HBsAg antibody induced	Folgori et al[54]
	M13 (pVIII and pIII)	(Selected from HBV-infected sera)	Φ13, Φ35 (CVTCDTPPTY) ΦIII/17, ΦIII41 and ΦpIII/13	Mice (intranasal/oral) cholera toxin as adjuvant	Anti-HBsAg antibody induced	Delmastro et al[56]
Phage-delivered DNA vaccine	λ	λ-gt11	HBsAg gene	Mice (subcutaneous)	Anti-HBsAg antibody induced	Clark et al[59]
	λ	λ-gt11	HBsAg gene	Rabbits (Intramuscular)	Anti-HBsAg antibody induced	Clark et al[61]

NA: Not applicable; HBV: Hepatitis B virus; HBsAg: Hepatitis B surface antigen; MHC: Major histocompatibility complex; HBcAg: Hepatitis B core antigen; CTL: Cytotoxic T lymphocyte.

Table 2 Epitope mapping of anti-hepatitis B virus antibodies

Antibodies against	Phage library used	Epitopes	Remarks	Ref.
PreS1 region
MA 18/7	M13 pIII 6-mer	ALDPAY, SLDPGF, PDPGFN, QLDPGF	The dipeptide DP was conserved from rounds 2 to 4 among all the analyzed phagotopes. Selected peptides were mapped to amino acids 19-23 of the PreS1 region	Germaschewski et al[134]
MA 18/7	M13 15-mer liner	SDTRGDPVFNLPFQ APVDSVFDRAFSAYL	Isolated peptides contain motif similar to LDPAF	D'Mello et al[135]
MA BX-182	M13 pIII 12-mer linear	SVPPPHTRSASG	Peptide matched amino acids 17SVPNP21 of the PreS1	Zhang et al[144]
	M13 pIII 7-mer disulfide constrained	CTNPVLRSC	Peptide spatially matched some amino acids within the same region but in a C- to N-terminal direction
PreS2 region
HBsAg polyclonal sera	M13 pIII 12-mer linear	TANGFYRLPSGS	Peptide sequence mapped to amino acids 135-146 of the PreS2 region	Zhang et al[136]
S-region
MA RFHBs6	M13 pIII 15-mer linear	TSNTHAC(R/K)TCSNPSR	The peptide sequence is similar to amino acids 115-129 of the S region	Motti et al[140]
MA BA1	M13 pIII 15-mer linear	PHDGNRAFPRTKVTM HMPRDANRHHQHPST SSLGSDHNARWVKRF	Low sequence homology with the S region
MA 6H6B6	M13 pIII 12-mer linear	WPHNWWPHFKVK	Peptide sequence homology not found	Jolivet-Reynaud et al[137]
	M13 pIII 6-mer linear	QGFLPQ	Peptide sequence mapped to amino acids 101-105 of the S-region
MA H166, H5, H35, H53	M13 pIII 30-mer linear	1Peptide Xn-CXTC-Xn	Sequence motif of CXTC was mapped to amino acids 121-124 of the S-region	Chen et al[138]
IgG derived from S-HBsAg immunized chimpanzee	M13 pIII 6-mer linear	TRVPRR, SRLPLR, SRLPKR	Sequence motif SxxPxR was mapped to amino acids 117-122 of the S-HBsAg	Germaschewski et al[139]

¹x_n represents random flanking amino acid sequences. Position X is constituted either by arginine, lysine or valine. MA: Monoclonal antibody; HBsAg: Hepatitis B surface antigen; IgG: Immunoglobulin G.