Production and Characterization of a Recombinant Camel Full Heavy Chain Antibody against Human IgE

Camel heavy chain antibodies (HCAbs) have novel properties that render them useful in diagnosis and immunotherapy of various diseases. The purpose of this study was to produce recombinant camel HCAbs directed against a synthetic loop polypeptide that mimics the FcεRІ binding site on human IgE. A recombinant camel HCAb was purified and characterized after being cloned using One Shot TOP10 Escherichia coli, expressed in BL21 Star (DE3) E. coli. Out of nineteen successful clones only one named IgG211 was found to contain the IgG2 HCAb coding sequence in the correct orientation with 85% homology to camel IgG2. A 62kDa fusion protein was expressed in an insoluble form under Isopropyl β-D-1- Thiogalactopyranoside (IPTG) induction. Probond purified fusion protein was localized by immunoblot using mouse anti camel antibody. The reactivity of recombinant camel IgG211to its corresponding antigen using ELISA was 72.9% of the camel polyclonal IgG2. Thus, a successful production of a recombinant camel HCAb of the IgG2 isotype was achieved. Such achievement may contribute towards the application of the unique properties of camel HCAbs in the field of antibody-based therapy for the treatment of asthma and allergy.