Recombinant Barley-produced Antibody for Bovine Milk Allergen Detection

Recombinant allergens and antibodies are important for diagnostic, therapeutic, food processing and quality verification purposes. Thus, researchers from VTT Technical Research Centre of Finland and International Centre for Genetic Engineering and Biotechnology developed a barley-based production system for detection of bovine milk allergen β-lactoglobulin (BLG) specific immunoglobulin E antibody (D1 scFv).

The researchers found that the expression level of the antibody in the best barley cell clone was 0.8–1.2 mg/kg fresh weight, which remained constant over an expression period of 3 weeks. In the case of barley grains, the highest stable productivity (followed up to T2 grains) was obtained when the D1 scFv cDNA was expressed under a seed-specific Glutelin promoter.

Translational fusion of ER retention signal significantly enhanced the build up of recombinant antibody. Furthermore, lines without ER retention signal lost D1 scFv accumulation in T2 grains. Pilot scale purification resulted in a yield of 0.47 mg of D1 scFv (31 kD) with high purity. Further analysis revealed that 29 percent of the purified protein was completely functional. The results indicate that the developed barley-based expression system can be used for application in the processing of dairy milk products as well as in detecting allergens from foods possibly contaminated by bovine milk.

Read the abstract at http://link.springer.com/article/10.1007/s11248-014-9783-2.