ABSTRACT
To identify the expression of the molecule recognized by Pf18-3 mAb (Pf18-3 molecule) on various cells. Meth-ods: The expression of pr18-3 molecule was assayed by flow cytometry and confocal laser scanning microscope . Result: The molecule recog-nized by Pf18-3 mAb expressed on TSC and other stromal cells. Whereas, fresh thymocytes were Pf18-3 negative. Interestingly, the expressionof Pf18-3 molecule was gradually up-regulated on thymocytes after activation by ConA. This molecule mainly expressed on CD4+ CD8+ andCD4+ CD8- cells. Under confocal laser scanning microscope, the staining of fluorescence showed as ring around the cell, it changed grsduallystronger and thicker with activation. Conclusion: This study indicated that the Pf18-3 molecule was co-expressive molecule of MTSC and acti-vated tlymocytes,it was concemed closely about the activation of CD4+ C D8+ and CD4+ CD8- cells.