AIM: To investigate the details of age-related changes of T lymphocytes in order to seek for sensitive biomarker for immunosenesence. METHODS: Heparin anticoagulated venous blood was collected freshly from young (20-35 years) and elderly (50-75 years) volunteers and three or four color immunofluorescence staining was performed. The nucleated cells were acquired and the phenotypes of T lymphocyte subpopulations were analyzed with flow cytometry. RESULTS: There was no significant difference in percentages of pan-T (CD3 +), helper T (CD4 +) and cytotoxic (CD8 +) T subsets between young and elderly, whereas the density of CD3 molecule (MFI) on T cells in elderly group decreased significantly. It was also found that the rates of CD44 + and CD62L + T cell subsets in young group did not have statistical difference from elderly. However,the rates of CD95 + pan-T, helper T and cytotoxic T subsets of elderly group were all markedly higher than that in young group. CONCLUSIONS: The relative rates of T cell and its subsets displayed no age-related changes while the density of CD3 was down-regulated during aging in these groups investigated. Moreover, the expression percentage of CD95 (Fas) on T cells increased as aging, suggesting that it is a potential biomarker for evaluating immunosenescence.

AIM: To investigate the expression of Th1-typed cytokine IFN-? and Th2-typed cytokine IL-4 on T lymphocytes that infiltrate in nasal polyps for searching the pathogenesis of nasal polyps. METHODS: Nasal polyps tissue samples and peripheral blood were obtained from 21 patients. Normal human inferior turbinate mucosa and peripheral blood were obtained as well. Flow cytometry was adopted to detect the expression of IFN-? and IL-4 of T lymphocytes. RESULTS: Th cytokines were rarely detected in inferior turbinate from normal human. Nasal polyps tissue consisted of abundant T lymphocytes. The expression of IL-4 and IFN-? increased in peripheral blood from patients [(6 686?0 204)%, (64 312?1 611)%, respectively] compared with normal human [(0 560?0 051)%, (0 246?0 020)%, respectively] ( P

AIM: To investigate whether wheat germ agglutinin (WGA) could induce apoptosis in mouse fibroblast cell line L929 and the possible molecular mechanism underlying. METHODS: The cells were exposed to WGA or its succinylated form (sWGA) for 24 h and both attached cells and the cells in supernatant were collected. The percentages of apoptotic cells were estimated by flow cytometry after staining with propidium iodide. Cell morphology was observed under fluorescence microscope after staining the cells with acridine orange. RESULTS: WGA treatment resulted in significant increase of the low DNA content peak (sub-G 1) that representing apoptotic cells, whereas sWGA did not. Morphologic study demonstrated that exposure to WGA induced nuclear fragmentation while sWGA not. CONCLUSION: These results indicate that WGA (specific for both sialic acid and GlcNAc) induces apoptosis in L929 cells, whereas sWGA (specific only for GlcNAc) does not. It is possible that binding to sialic acid residues on the cell surface of L929 is essential for WGA to induce apoptosis. Apoptosis induction may be, at least in part, involved in the cytotoxicity of WGA. [