Investigating the relationship between CD20-Rituximab binding force and mechanical properties of Lymphom B cells using atomic force microscopy

The invention of atomic force microscopy (AFM) provides new technology for investigating the physiological activities at the single cell and single molecule levels. Lymphoma Raji cells were adsorbed onto the glass slides by coating the glass slides with poly-L-lysine. Rituximabs (anti-CD20 antibody) were linked onto the AFM tip by PEG linker and the CD20-Rituximab binding forces were measured on three lymphoma Raji cells. Then the mechanical properties of the Raji cells were dynamically measured after the Rituximab activation by obtaining force curves on the cell surface. The mechanical properties of lymphoma cells kept stable at the first 20-30 min, and then decreased markedly. Besides, as the CD20-Rituximab binding force increased, the mechanical properties decrease rate increased. The experimental results indicated that the Rituximab's effect is related to CD20-Rituximab binding force and can improve our understanding of Rituximab's variable efficacies in different patients.