AFM detection of biophysical characteristics of specific regulatory T Cells after allogeneic hematopoietic stem cell transplantation

Background: Based on the dynamics of antigen recognition from T cell receptor complex and T cell activation, different function of T cells may present different morphology feature, at least at molecular level. Regulatory T (Treg) cells play a critic role in regulation the onset of graft versus host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Little is known about their morphology feature which may relate to the regulating function in GVHD. Results: In this study, we detected the biophysical architectural changes of specific Treg cells subsets after allo-HSCT using biological atomic force microscopy to characterize their biological characteristics and improve our understanding of cell structure-function relationships in GVHD. There were dramatic overall shape and surface membrane deformations of the Treg cells associated with patients at GVHD onset or without GVHD. The Treg cells at GVHD onset or without GVHD could be distinguished by the morphologic parameters of morphology, membrane nanostructure, and membrane pore. These AFM parameters of Treg cells morphology differed obviously between GVHD and without GVHD. The multiple irregular microspikes could be observed on the surface of Treg cells without GVHD. Conclusions: The remarkable biological morphology changes in the cell membrane structure of Treg cells after allo-HSCT might be related to the function of Treg cells which could inhibit the occurrence and development of GVHD.