Mammalian cell display for the discovery and optimization of antibody therapeutics

Methods. 2014 Jan 1;65(1):44-56. doi: 10.1016/j.ymeth.2013.06.010. Epub 2013 Jun 20.


Recent advances are described for the isolation and affinity maturation of antibodies that couple in vitro somatic hypermutation (SHM) with mammalian cell display, replicating key aspects of the adaptive immune system. SHM is dependent on the action of the B cell specific enzyme, activation-induced cytidine deaminase (AID). AID-directed SHM in vitro in non-B cells, combined with mammalian display of a library of human antibodies, initially naïve to SHM, can be used to isolate and affinity mature antibodies via iterative cycles of fluorescence-activated cell sorting (FACS) under increasingly stringent sort conditions. SHM observed in vitro closely resembles SHM observed in human antibodies in vivo in both mutation type and positioning in the antibody variable region. In addition, existing antibodies originating from mouse immunization, in vivo based libraries, or alternative display technologies such as phage can also be affinity matured in a similar manner. The display system has been developed to enable simultaneous high-level cell surface expression and secretion of the same protein through alternate splicing, where the displayed protein phenotype remains linked to genotype, allowing soluble secreted antibody to be simultaneously characterized in biophysical and cell-based functional assays. This approach overcomes many of the previous limitations of mammalian cell display, enabling direct selection and maturation of antibodies as full-length, glycosylated IgGs.

Keywords: AID; Antibody; Mammalian cell display; Somatic hypermutation.

MeSH terms

  • Animals
  • Antibodies, Monoclonal / genetics*
  • Antibodies, Monoclonal / isolation & purification
  • Antibodies, Monoclonal / metabolism
  • Antibody Affinity
  • Antigens / immunology
  • Base Sequence
  • Cell Separation
  • DNA Primers / genetics
  • Directed Molecular Evolution
  • Drug Discovery
  • Flow Cytometry
  • Gene Library
  • HEK293 Cells
  • Humans
  • Molecular Sequence Data
  • Protein Binding
  • Protein Engineering


  • Antibodies, Monoclonal
  • Antigens
  • DNA Primers