FCGRT Knockout ST Cell Line

Yes. FcRn rescue experiments require attention to heterodimer formation and pH-sensing: • Construct design: use a codon-modified FcRn (FCGRT) sequence with a small intracellular C-terminal tag (FLAG, HA). FcRn (FCGRT) heavy chain associates non-covalently with β2-microglobulin (B2M) for surface expression — both subunits required. • pH-binding-deficient rescue: H310A/H433A and other histidine residue mutations abolish pH-dependent IgG binding and serve as the standard specificity control. • B2M partnership: rescue interpretation considers B2M expression — both FCGRT heavy chain and B2M are required for surface FcRn. • Functional readout: rescue should restore pH 6.0 IgG binding and pH 7.4 IgG release, and IgG transcytosis activity. ST-specific considerations: • ST is a porcine testicular cell line widely used for swine virus research (transmissible gastroenteritis virus TGEV, porcine epidemic diarrhea virus PEDV) and porcine-specific receptor biology. • Lentiviral transduction efficiency in ST cells may require optimization; the porcine species background must be considered for ortholog and antibody cross-reactivity. • Cell line authentication is recommended.

Primary applications: • IgG pH-dependent binding: IgG binding to FcRn at pH 6.0 (endosomal mimic) and pH 7.4 (extracellular mimic) by SPR or BLI. • Porcine IgG biology: in heterologous porcine immunology contexts, characterization of porcine FcRn-IgG interactions. • FcRn antagonist specificity: critical genetic control for efgartigimod (FDA-approved for myasthenia gravis), rozanolixizumab, nipocalimab in autoantibody-mediated disease. • Antibody half-life engineering: YTE (M252Y/S254T/T256E), LS (M428L/N434S), AAA (S298A/E333A/K334A) Fc variants affecting FcRn binding. EDITGENE recommends this porcine model for researchers investigating FcRn-IgG biology, particularly in agricultural/veterinary immunology and xenotransplantation contexts.

The choice depends on whether you are studying FcRn (neonatal Fc receptor)'s role in IgG and albumin homeostasis or modeling porcine IgG biology and transcytosis. The Knockout line is the standard tool for asking whether FcRn is required for these processes — FcRn is a non-classical MHC class I-like receptor expressed on epithelial cells, endothelial cells, and antigen-presenting cells; FcRn binds IgG at acidic pH (early endosome) and releases at neutral pH (cell surface), enabling IgG transcytosis (gut absorption in neonates, placental transfer) and IgG recycling (extending IgG serum half-life to ~3 weeks). Overexpression is useful for studying FcRn in heterologous expression contexts. For porcine immunology and transcytosis research, the EDITGENE FcRn Knockout in ST is uniquely valuable — ST is a porcine testicular cell line, and porcine FcRn has specific applications in agricultural immunology and xenotransplantation research. Rescue with wild-type or pH-binding-deficient (H310A/H433A) FcRn enables structure-function studies. The knockout is valuable for studying IgG pharmacokinetics, antibody half-life extension strategies (YTE, LS, AAA mutations enhance FcRn binding), and FcRn antagonists (efgartigimod, FDA-approved for myasthenia gravis; rozanolixizumab; nipocalimab — for autoantibody-mediated diseases).