Figure 1.

Non-combinatorial mining of human antibody repertoires. (A) Human antibody repertoires consist of polyclonal mixtures of a variety of B cells that express functional human antibodies, including naive and post-GC B cells that represent naïve and immune repertoires, respectively. Post-GC B cells, which differentiate into antibody secreting cells and memory B cells, provide a human antibody repertoire that has been extensively mined with non-combinatorial strategies. (B) Hybridoma technology (top), EBV immortalization (center), and single-cell sorting (bottom) allow the isolation and expansion of monoclonal B cells which are then screened with an antigen of interest. Cell surface Ig can be utilized to first enrich B cells that express human antibodies to the antigen of interest. (C) Heavy and light chain cDNAs are amplified from mRNA of monoclonal B cells and B-cell lines by RT-PCR. (D) After cloning heavy and light chain cDNAs into ectopic expression vectors, human mAbs are purified from the supernatant of transfected mammalian cells (typically Chinese hamster ovary CHO or mouse myeloma NS0 cells) in high yields.