AFM- and NSOM-based force spectroscopy and distribution analysis of CD69 molecules on human CD4+ T cell membrane.
Although CD69 is well known as an early T cell-activation marker, the possibility that CD69 are distributed as nano-structures on membrane for immune regulation during T cell activation has not been tested. In this study, nanoscale features of CD69 expression on activated T cells were determined using the atomic force microscopy (AFM) topographic and force-binding nanotechnology as well as near-field scanning optical microscopy (NSOM)-/fluorescence quantum dot (QD)-based nanosacle imaging. Unstimulated CD4(+) T cells showed neglectable numbers of membrane CD69 spots binding to the CD69 Ab-functinalized AFM tip, and no detectable QD-bound CD69 as examined by NSOM/QD-based imaging. In contrast, Phytohemagglutinin (PHA)-activated CD4(+) T cells expressed CD69, and displayed many force-binding spots binding to the CD69 Ab-functionalized AFM tip on about 45% of cell membrane, with mean binding-rupture forces 276 +/- 71 pN. Most CD69 molecules appeared to be expressed as 100-200 nm nanoclusters on the membrane of PHA-activated CD4(+) T cells. Meanwhile, NSOM/QD-based nanoscale imaging showed that CD69 were non-uniformly distributed as 80-200 nm nanoclusters on cell-membrane of PHA-activated CD4(+) T cells. This study represents the first demonstration of the nano-biology of CD69 expression during T cell activation.
Hu
Mingqian
M
Department of Chemistry, Jinan University, Guangzhou, Guangdong 510632, China.
Chen
Jianan
J
Wang
Jiongkun
J
Wang
Xiaoping
X
Ma
Shuyuan
S
Cai
Jiye
J
Chen
Crystal Y
CY
Chen
Zheng W
ZW
D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D001695:Biology / Q000379:methods; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology*; D002462:Cell Membrane / Q000378:metabolism*; D006801:Humans; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D008853:Microscopy / Q000379:methods; D018625:Microscopy, Atomic Force / Q000379:methods*; D008856:Microscopy, Fluorescence / Q000379:methods; D036103:Nanotechnology / Q000379:methods; D055095:Optics and Photonics; D010835:Phytohemagglutinins / Q000737:chemistry; D012984:Software; D013601:T-Lymphocytes / Q000737:chemistry / Q000276:immunology*; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D037181:Lectins, C-Type; D010835:Phytohemagglutinins; D000099192:CD69 Antigens