A novel variable antibody fragment dimerized by leucine zippers with enhanced neutralizing potency against rabies virus G protein compared to its corresponding single-chain variable antibody fragment.
Fatal rabies can be prevented effectively by post-exposure prophylactic (PEP) with rabies immunoglobulin (RIG). Single-chain variable fragments (scFv), which are composed of a variable heavy chain (VH) and a variable light chain (VL) connected by a peptide linker, can potentially be used to replace RIG. However, in our previous study, a scFv (scFV57S) specific for the rabies virus (RV) G protein showed a lower neutralizing potency than that of its parent IgG due to lower stability and altered peptide assembly pattern. In monoclonal antibodies, the VH and VL interact non-covalently, while in scFvs the VH is connected covalently with the VL by the artificial linker. In this study, we constructed and expressed two peptides 57VL-JUN-HIS and 57VH-FOS-HA in Escherichia coli. The well-known Fos and Jun leucine zippers were utilized to dimerize VH and VL similarly to the IgG counterpart. The two peptides assembled to form zipFv57S in vitro. Due to the greater similarity in structure with IgG, the zipFv57S protein showed a higher binding ability and affinity resulting in notable improvement of in vitro neutralizing activity over its corresponding scFv. The zipFv57S protein was also found to be more stable and showed similar protective rate as RIG in mice challenged with a lethal dose of RV. Our results not only indicated zipFv57S as an ideal alternative for RIG in PEP but also offered a novel and efficient hetero-dimerization pattern of VH and VL leading to enhanced neutralizing potency.
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China.
Zhuang
Z
Li
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China.
Yue
Y
Cheng
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China.
Hualong
H
Xi
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
Tiejun
T
Gu
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China.
Ruosen
R
Yuan
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China.
Xiaoxu
X
Chen
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
Chunlai
C
Jiang
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China. Electronic address: weikong@jlu.edu.cn.
Wei
W
Kong
National Engineering Laboratory for AIDS Vaccine, School of Life Science, Jilin University, Changchun 130012, China; Key Laboratory for Molecular Enzymology and Engineering of the Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China. Electronic address: ygwu@jlu.edu.cn.
Yongge
Y
Wu
D000818:Animals; D057134:Antibodies, Neutralizing / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D003412:Cricetulus; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D057809:HEK293 Cells; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000008:administration & dosage; D016350:Leucine Zippers / Q000235:genetics* / Q000276:immunology; D051379:Mice; D009500:Neutralization Tests; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D055503:Protein Multimerization; D011818:Rabies / Q000276:immunology / Q000517:prevention & control* / Q000821:virology; D011819:Rabies Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D011820:Rabies virus / Q000276:immunology; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D057127:Single-Chain Antibodies / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D016019:Survival Analysis; D014759:Viral Envelope Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology
D057134:Antibodies, Neutralizing; D007074:Immunoglobulin G; D011819:Rabies Vaccines; D011994:Recombinant Proteins; D057127:Single-Chain Antibodies; D014759:Viral Envelope Proteins
Glycoprotein; Leucine zipper; Rabies virus; Single chain variable fragment; Virus-neutralization antibody; Zip variable fragment