TY - JOUR
T1 - Whispering Gallery Modes-based biosensors for real-time monitoring and binding characterization of antibody-based cancer immunotherapeutics
AU - Freile, Jimena Alvarez
AU - Choukrani, Ghizlane
AU - Zimmermann, Kerstin
AU - Bremer, Edwin
AU - Daehne, Lars
PY - 2021/11/1
Y1 - 2021/11/1
N2 - Development of novel protein-based drugs such as antibodies or immunocytokines and initial validation of target binding typically occurs in 2D settings with e.g., surface plasmon resonance or reflection interferometry using antigen-coated planar sensors. However, a versatile tool to assess binding characteristics of tumour-targeting therapeutics where specific biochemical interactions can be monitored in real-time and in a more realistic 3D interaction setting is currently lacking. Here, we report on the development of versatile small optical 3D biosensors using protein G-coated spherical microparticles based on Whispering Gallery Modes (WGMs). These sensors allowed for an oriented immobilization of theoretically any immunoglobulin G (IgG) and IgG crystallizable fragment domain (Fc)-tagged protein and have been carefully optimized for specific detection of antigenantibody interactions, as illustrated using the Epithelial Growth Factor Receptor (EGFR) antibody Cetuximab and Program Death Ligand 1 (PD-L1) antibody Atezolizumab. When both ligand and analyte contained an Fcfragment, protein G binding capacity saturation followed by a "blocking" step with an irrelevant IgG enabled the label-free detection of Fc-tagged antigens with corresponding cognate ligands, as identified using EGFR-Fc, PD-L1-Fc and different members from the tumour necrosis factor receptor family, such as CD27-Fc and 4- 1BBFc. Thus, WGMs and developed protein G-coated biosensors provide a widely applicable tool to evaluate binding of immunotherapeutics to their targets on the sensor surface, imitating cell surface properties.
AB - Development of novel protein-based drugs such as antibodies or immunocytokines and initial validation of target binding typically occurs in 2D settings with e.g., surface plasmon resonance or reflection interferometry using antigen-coated planar sensors. However, a versatile tool to assess binding characteristics of tumour-targeting therapeutics where specific biochemical interactions can be monitored in real-time and in a more realistic 3D interaction setting is currently lacking. Here, we report on the development of versatile small optical 3D biosensors using protein G-coated spherical microparticles based on Whispering Gallery Modes (WGMs). These sensors allowed for an oriented immobilization of theoretically any immunoglobulin G (IgG) and IgG crystallizable fragment domain (Fc)-tagged protein and have been carefully optimized for specific detection of antigenantibody interactions, as illustrated using the Epithelial Growth Factor Receptor (EGFR) antibody Cetuximab and Program Death Ligand 1 (PD-L1) antibody Atezolizumab. When both ligand and analyte contained an Fcfragment, protein G binding capacity saturation followed by a "blocking" step with an irrelevant IgG enabled the label-free detection of Fc-tagged antigens with corresponding cognate ligands, as identified using EGFR-Fc, PD-L1-Fc and different members from the tumour necrosis factor receptor family, such as CD27-Fc and 4- 1BBFc. Thus, WGMs and developed protein G-coated biosensors provide a widely applicable tool to evaluate binding of immunotherapeutics to their targets on the sensor surface, imitating cell surface properties.
KW - Whispering Gallery Modes
KW - Optical biosensor
KW - Cancer immunotherapy
KW - Drug development
KW - Label-free analytics
KW - PROTEIN-A
KW - IMMOBILIZATION
KW - CAPACITY
KW - SINGLE
U2 - 10.1016/j.snb.2021.130512
DO - 10.1016/j.snb.2021.130512
M3 - Article
VL - 346
JO - Sensors and Actuators B: Chemical
JF - Sensors and Actuators B: Chemical
SN - 0925-4005
M1 - 130512
ER -