GenScript offers FcγRs and FcRn overexpression cell lines with binding capabilities spanning all IgG subclasses. These cell lines are designed for cell-based binding assays to evaluate Fc-FcγR and Fc-FcRn binding affinity.
Following binding with the Fc region of antibodies that are attached to pathogens or infected cells, FcγRs can mediate effector functions including antibody-dependent cellular phagocytosis (ADCP) or antibody-dependent cell-mediated cytotoxicity (ADCC). During Fc engineering in antibody based drug development, increasing or decreasing Fc-FcγR binding affinity could potentially strengthen or weaken effector functions. FcRn involves in recycling of IgG type antibodies in serum, which increases the stability and half-life of antibodies. Hence, antibody Fc engineering for enhanced Fc-FcRn binding affinity could prolong the circulation half-life of antibody.
Figure 1: Fc receptor expressing cells based binding assay
Cell-based binding assay with flow cytometer is one of the accessible methods to evaluate binding affinity.
Single-nucleotide polymorphism contributes to polymorphic FcγRs that can effect an individual’s immune response to antibody based drugs or immune therapies. Same antibody based drugs may have different efficiencies in patients with polymorphic FcγRs. GenScript offers polymorphic FcγRs overexpression cell lines for performing polymorphism studies.
Table 1: Immunoglobulin subclass binding and functions of Human FcRγ and FcRn receptors.
|name||Alias||Polymorphism||IgG subclass binding||Function|
|FcγRIIIa||CD16A||V158||Higher affinity to all human IgGs than F158||Activation /Inhibition|
|F158||Lower affinity to all human IgGs than V158||Activation /Inhibition|
|R131||lower affinity to IgG1 and IgG2 than H131, IgG3, IgG4||Activation /Inhibition|
|FcRn||FcRn||-||IgG1,IgG2,IgG3,IgG4||Recycling, transport, uptake|