Background
Recent evidence of clinical trials highlights that the combination of two noncompetitive anti-EGFR antibodies can benefit patients with several cancers. Previous studies propose that a lattice complex assembled by antibodies and EGFR down-regulates surface EGFR by rapid internalization of the complex. However, there remains a paucity of evidence and understanding on the existence of a lattice complex on cell surface and its cellular processes of internalization.
Conclusions
The above data suggests that large-size lattice complex affects membrane fluidity and dynamic reorganization of cytoskeletal, which may be responsible for its rapid internalization. These new insight will aid in current rational combination design of anti-EGFR antibodies.
Methods
Herein, we used three dimensions structured illumination microscopy to directly observe the actual morphology of the lattice complex formed on Hela cell membrane after noncompetitive anti-EGFR antibody combinations, and we explored the internalized mechanism of noncompetitive antibody combinations by constructing a PIP2 consumption system. Result: We observed the lattice complex (length > 1 μm) on the surface of living cell after preincubation with Cetuximab and H11, but combination of Cetuximab and single domain antibody 7D12 fails to assemble the lattice, these