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Multiparametric Atomic Force Microscopy Identifies Multiple Structural and Physical Heterogeneities on the Surface of Trypanosoma brucei
journal contribution
posted on 2020-08-14, 00:13 authored by Claire Valotteau, Andra C. Dumitru, Laurence Lecordier, David Alsteens, Etienne Pays, David Pérez-Morga, Yves F. DufrêneA unique
feature of the African trypanosome Trypanosoma
brucei is the presence of an outer layer made of densely
packed variable surface glycoproteins (VSGs), which enables the cells
to survive in the bloodstream. Although the VSG coat is critical to
pathogenesis, how exactly the glycoproteins are organized at the nanoscale
is poorly understood. Here, we show that multiparametric atomic force
microscopy is a powerful nanoimaging tool for the structural and mechanical
characterization of trypanosomes, in a label-free manner and in buffer
solution. Directly correlated images of the structure and elasticity
of trypanosomes enable us to identify multiple nanoscale mechanical
heterogeneities on the cell surface. On a ∼250 nm scale, regions
of softer (Young’s modulus ∼50 kPa) and stiffer (∼100
kPa) elasticity alternate, revealing variations of the VSG coat and
underlying structures. Our nanoimaging experiments show that the T. brucei cell surface is more heterogeneous than previously
anticipated and offer promising prospects for the design of trypanocidal
drugs targeting cell surface components.