Leow Chiuan Herng

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leow

Name

Leow Chiuan Herng

Current Position

Senior Lecturer

Email

herng.leow@usm.my

Office Telephone

+604-6534886

Personal Lab Website

None

Qualifications

B.Sc. (Hons) (Microbiology), Universiti Putra Malaysia (2002)

M.Sc. (Pharm Biotechnology), Universiti Sains Malaysia (2006)

PhD (Medicine), University of Queensland, Australia (2014)

Affiliations

Member of The Antibody Society (USA)

Member of Malaysian Society of Parasitology and Tropical Medicine (MSTPM)

Affiliate of Young Scientists Network?Academy of Sciences Malaysia (YSN-ASM)

Research Interests

Antibody, Fermentation, Immunology, Single domain antibody, Phage display, Recombinant protein expression

Research Overview 1

Exploration of shark single domain antibodies

Antibodies are the most useful molecules for biomedical applications. In recent years, a new set of natural sdAb fragments namely VHHs, VNARs and VLRs were discovered in camelids, sharks and lampreys, respectively. Due to their unique characteristics, including small size, high thermostability and long CDR3 region for better penetration, these new binders are now investigated extensively as a substitute for conventional antibodies.His laboratory is currently interested to explore the functional of shark VNARs by constructing naive, immunized and semi-synthetic antibody libraries targeting towards range of antigens derived from different diseases.

Research Overview 2

Isolation of anti-salbutamol scFv from chicken phage display library

To date, salbutamol is a preferred ?2-agonist drug of abuse in athletics and as a livestock growth promoter due to its inexpensiveness. Antibodies remain key biomolecules for the detection and isolation of ?2-agonists.  In this study, the use of the chicken (Gallus gallus domesticus) as an immunization host for the generation of a monoclonal anti-salbutamol antibody by phage display is investigated. A single chicken immunized against SAL-KLH conjugate was used to construct the phage display library  from which a single scFv clone was isolated and was reactive to salbutamol. Soluble and functional scFv protein was expressed in Escherichia coli T7 SHuffle Express B (DE3) strain .

The scFv was then reformatted into scFv-murine-IgG1 Fc by expression in HEK 293T cells. Further evaluation of the cross-reactivity of the two antibody formats towards other relevant ?2-agonists revealed that the antibodies had significant cross-reactivity towards clenbuterol. Based on the affinity of the antibodies towards the two ?-agonists (IC50 salbutamol = ~0.310 ?g/ml (scFv), x ?g/ml (scFv-Fc); IC50 clenbuterol = ~0.076 ?g/ml (scFv), y ?g/ml (scFv-Fc)), they were deemed potentially suitable as antibodies for immunochromatographic-capture solid phase extraction (SPE) for the simultaneous detection of salbutamol and clenbuterol by more sensitive methods such as LC-MS or GC-MS.

Research Overview 3

Exploration of anti-JE NS1 from human scFv library

Japanese Encephalitis virus( JEV) is known to be serologically similar with other flavivirus such as Dengue virus, West NileZika virus, Yellow Fever virus and  others. Co-existence of these viruses with highly homologous antigenic epitopes results in antibody-based serodiagnosis being inefficient at detecting and distinguishing JEV efficiently from other flaviviruses. This often causes misdiagnosis and inaccurate treatments of flavivirus infection. Co-localization of the JEV NS1 protein with the membrane of JEV-infected cells renders the protein a potential target. For this reason, the NS1 viral replication protein that is reported to confer specificity against JEV is frequently used as antigenic marker in this study to generate human antibody fragment against JEV. For futureTo imporove  the JEV diagnostic applicationtest, we have constructed a human semi-synthetic library that displaying single chain antibody fragment. Complementary determining region 3 (CDR3) of heavy chain and light chain are synthetically randomized by using degenerate codons. VH and VL are were then linked via glycine-serine linker by splice overlap extension PCR strategy in respect to form construct a highly diverse scFv phage display antibody library. Of that, a library size of 4.8 x 106 is generated. DNA sequencing revealed the quality of library constructed in this study was good with that approximately 60% of in-frame the libraryscFv repertoires identified has the potential to express in- frame scFvs. As a result, it may lead to  This antibody repertoire is highly diverse with all the clones sequenced confer distinct and unique sequences at the CDR3. Presently, this library is ready to deploy for specific clones selection against our in-house synthetic recombinant JE NS1 proteinby undertaking repetitive biopanning.

Selected Publications

  1. Warren Lee a, Ali Syed Atif b, Soo Choon Tan a, Chiuan Herng Leow. (2017) Insights into the chicken IgY with emphasis on the generation and applications of chicken recombinant monoclonal antibodies. Journal of Immunological Methods (In Press).
  2. Herng C. Leow, Martina L. Jones, Qin Cheng, Stephen M. Mahler, James S. McCarthy. (2014). Production and Characterization of a Specific Monoclonal Antibody binding the Plasmodium falciparum Diagnostic Biomarker, Histidine-Rich Protein 2. Malaria Journal. 13:277, 1-12.
  3. Gam, LH., Leow, CH., Man, CN., Gooi, BH., Manjit, S.  (2006). Analysis of differentially expressed proteins in cancerous and normal colonic tissues.  World J. Gastroenterol. 12(31): 4973-4983.

Author Links

Google Scholar

Researcher ID: F-8877-2014

ORCID

ResearchGate

Scopus