Contact person: Jeanni Fehrsen (Ph.D)
Email: FehrsenJ@arc.agric.za
Tel: +27 (0)12 529 5257

 

Antibodies are important mediators of immune protection, particularly in the case of many viral diseases. Accordingly, this unit concentrates on investigating and characterising B cell antigens as well as immunoglobulins and their genes. In addition, it develops and investigates novel immunological reagents aimed at monitoring disease progression, vaccination efficacy and antigen production. Recombinant antibody technology and epitope mapping are central to its research efforts.  It is also involved in antibody engineering, epitope mapping and investigating novel recombinant antibody scaffolds. Using its novel chicken scFv technology platform, the immunochemistry laboratory is also able to provide recombinant antibodies to internal or external clients.

​

New Generation Vaccines Programme

​ Cellular Immunology 

  ​Protein Expression and Purification

  ​Vectors and Delivery systems

 

Staff members

This group exploits phage display to isolate recombinant antibodies and map epitopes on proteins. Random peptide libraries as well as gene- or genome-targeted peptide libraries are used to find antigenically important epitopes and their encoding genes. The identified proteins are expressed in bacterial, yeast or mammalian expression systems.

Using OVI’s patented recombinant antibody platform, single chain antibody variable fragments (scFvs) derived from chicken immunoglobulin genes that recognise a large variety of haptens, proteins and viruses have been isolated. Several of these scFvs have been incorporated into immunoassays such as ELISAs and lateral flow tests. Some have been engineered to improve their binding, while others were reconstituted to antibody-like molecules (gallibodies) and expressed in a mammalian expression system. In addition, immune libraries are constructed tailored to client specifications. Binding characteristics of the scFvs and their target (or any two binding partners) can be analysed by surface plasmon resonance on a BiacoreX.

 

Key publications

Sixholo, J., van Wyngaardt, W., Mashau, C., Frischmuth, J., Du Plessis, D.H. and Fehrsen. 2011. Improving the characteristics of a mycobacterial 16kDa-specific chicken scFv. Biologicals. 39,110-116. doi:10.1016/j.biologicals.2011.01.007

Wemmer, S., Mashau, C., Fehrsen, J., Wyngaardt, W. and du Plessis, D.H., 2010. Chicken scFvs and bivalent scFv-CH fusions directed against HSP65 of Mycobacterium bovis. Biologicals. 38, 407-414. doi:10.1016/j.biologicals.2010.02.002

Fehrsen, J., van Wyngaardt, W., Mashau, C., Potgieter, C., Chaudhary, V.K., Gupta,A., Jordaan, F. and du Plessis, D.H., 2005. Serogroup-reactive and type-specific detection of bluetongue virus antibodies using chicken scFvs in inhibition ELISAs. Journal of Virological Methods. 129(1), 31-9.

Van Wyngaardt W, Malatji T, Mashau C, Fehrsen J, Jordaan F, Miltiadou DR, Du Plessis DH. A large semi-synthetic single-chain Fv phage display library based on chicken immunoglobulin genes. BMC Biotechnology. 2004 Apr 1;4(1):6.

Van Wyngaardt W., Du Plessis, D.H., Van Wyngaardt, S. & Verschoor, J.A. 1992. Production and properties of monoclonal antibodies against African horsesickness serotype 3. Onderstepoort Journal of Veterinary Research. 59, 129-133.

Van Wyngaardt W. and Du Plessis, D.H., 1998. Selection of a scFv phage antibody that recognises bluetongue virus from a large synthetic library and its use in ELISAs to detect viral antigen and antibodies. Onderstepoort Journal of Veterinary Research. 65, 125-131. ​