Selection of Vaccinia Virus-Neutralizing Antibody from a Phage-Display Human-Antibody Library.

Abstract

Although smallpox was eradicated in 1980, it is still considered a potential agent of biowarfare and bioterrorism. Smallpox has the potential for high mortality rates along with a major public health impact, eventually causing public panic and social disruption. Passive administration of neutralizing monoclonal antibodies (mAbs) is an effective intervention for various adverse reactions caused by vaccination and the unpredictable nature of emerging and bioterrorist-related infections. Currently, vaccinia immune globulin (VIG) is manufactured from vaccinia vaccine-boosted plasma; however, this production method is not ideal because of its limited availability, low specific activity, and risk of contamination with blood-borne infectious agents. To overcome the limitations of VIG production from human plasma, we isolated two human single chain variable fragments (scFvs) (SC34 and SC212) bound to vaccinia virus (VACV) from a scFv phage library constructed from the B cells of VACV vaccine-boosted volunteers. The scFvs were converted to human IgG1 (VC34 and VC212). These two anti-VACV mAbs were produced in Chinese Hamster Ovary (CHO) DG44 cells. The binding affinities of VC34 and VC212 were estimated by competition ELISA to IC50 values of 2 μg/mL (13.33 nM) and 22 μg/mL (146.67 nM), respectively. Only the VC212 mAb was proven to neutralize the VACV, as evidenced by the plaque reduction neutralization test (PRNT) result with a PRNT50 of ~0.16 mg/mL (~1.07 μM). This VC212 could serve as a valuable starting material for further development of VACV-neutralizing human immunoglobulin for a prophylactic measure against post-vaccination complications and for post-exposure treatment against smallpox.

• Authors: Yong Won Shin, Ki-Hwan Chang, Gwang-Won Hong, Sang-Gu Yeo, Youngmee Jee, Jong-Hyun Kim, Myoung-Don Oh, Dong-Hyung Cho, Se-Ho Kim
• Journal: Journal of microbiology and biotechnology (J Microbiol Biotechnol) Vol. 29 Issue 4 Pg. 651-657 (Apr 28 2019) ISSN: 1738-8872 [Electronic] Korea (South)
• PMID: 30856707 (Publication Type: Journal Article)

Chemical References

• Antibodies, Monoclonal
• Antibodies, Neutralizing
• Antibodies, Viral
• Immunoglobulin G
• Immunoglobulins
• Single-Chain Antibodies
• Smallpox Vaccine
• Vaccines, Synthetic
• SRSF2 protein, human
• Serine-Arginine Splicing Factors

Topics

• Amino Acid Sequence
• Animals
• Antibodies, Monoclonal (immunology)
• Antibodies, Neutralizing (immunology)
• Antibodies, Viral (biosynthesis, genetics, immunology)
• B-Lymphocytes
• Bacteriophages
• Bioterrorism
• CHO Cells
• Cell Surface Display Techniques (methods)
• Cloning, Molecular
• Cricetinae
• Cricetulus
• Escherichia coli (genetics)
• Gene Library
• Humans
• Immunoglobulin G
• Immunoglobulins (genetics)
• Neutralization Tests
• Serine-Arginine Splicing Factors (isolation & purification)
• Single-Chain Antibodies (genetics, immunology, isolation & purification)
• Smallpox (immunology, prevention & control)
• Smallpox Vaccine (immunology)
• Vaccination
• Vaccines, Synthetic (genetics, immunology, therapeutic use)
• Vaccinia virus (genetics, immunology)