T lymphocytes, key mediators of the adaptive immune response, are activated when their T-cell receptors (TCRs) interact with cognate antigenic peptides displayed by major histocompatibility complex molecules (MHC). E. coli expression and in vitro protein refolding is a common method to produce MHC-I complex. Based on SAMSTM_Mam MHCTMplatform, KACTUS succeeded in expressing biotinylated MHC-I complex in mammalian cell Expi293. The resulting MHC-I complexes show high affinities with benchmark antibodies and have low endotoxin levels – ideal for endotoxin sensitive cell-based assay. KACTUS also provide MHC tetramer complex which has greater avidity to the T cell m and maintains more stable binding.
MHC class I maturation, ligand binding, and presentation on the cell surface ( Kuznetsov A, et.al, 2020)
-Mammalian expression with Post-translational modification
-Good binding affinity
-Flexible choice: monomer or tetramer
Bioactivity assay of Kactus human HLA-A*0201 WT-1 peptide complex tetramer protein by ELISA.
SPR result of Kactus human HLA-A*0201 WT-1 peptide complex protein tetramer with WT-1 antibody.