基于原子力显微镜的人外周血CD8(上标 +)T细胞形貌观察与力谱分析

In this study, CD8(superscript +)T cells were firstly isolated from human peripheral blood in vitro and activated by phytohaemagglutinin (PHA). Morphology of cells was observed by atomic force microscopy (AFM) and distribution of CD8 antigen molecules of CD8(superscript +)T cells were studied by a functionalized AFM tip. Laser confocal scanning microscope (LCSM) experiment showed that the CD8 antigen molecules were distributed over the CD8(superscript +)T cells, and the AFM experiment showed that comparing to resting CD8(superscript +)T cells, the diameter and height of activated CD8(superscript +)T cells became large, the ultrastructure of the cells became complex; the strength of the specific binding force of the CD8 antigen-antibody interaction was found to be approximately four times bigger than that of the unspecific force. The CD8 antigen molecules were not randomly distributed over the surface of a single activated CD8(superscript +)T cell, they were formed into nanometer domain, the CD8 molecules were gathered obviously. The force of CD8 antigen-antibody interaction of CD8(superscript +)T cell did not changed significantly when CD8(superscript +)T cells were activated, these results suggest that CD8 antigen-antibody interaction is highly selected and high affinity. Atomic force microscopy can provide a new tool to study the specificity T cell antigen recognition and activation, it makes us to better clarify the T cell antigen recognition and activation mechanism.