Nanoscale Organization of CD4 Molecules of Human T Helper Cell Mapped by NSOM and Quantum Dots

CD4 molecule, the surface marker of T helper cell, has been comfirmed to be the main cellular receptor for the human immunodeficiency Viruses HIV-1, HIV-2 and SIV. Recent research demonstrated the importance of the spatial arrangement of CD4 on the cell membrane to its binding efficiency to virus. In this article, the combined near-field scanning optical microscopy (NSOM) and quantum dots (QDs) fluorescent labeling technology were performed to investigate the nanoscale organization of CD4 molecules with a spatial resolution about 100 nm. Simultaneous topographic image of the T helper cell and fluorescent Image of QDs have been directly gained by NSOM/QDs-based system. Intensity- and size-distribution histograms of the QDs fluorescent spots verify that approximately 80% of the CD4 molecules are organized in nanosized domains randomly distributed on the cell surface. Intensity-size correlation analysis revealed heterogeneity in the molecular packing density of the domains. Our results also Illustrated the combination of NSOM imaging and QDs labeling is an ultrasensitive. high-resolution technique to probe nanoscale organization of molecules on the cell Surface. SCANNING 30: 448-451, 2008. (C) 2008 Wiley Periodicals, Inc.