[Correlation between CD154 (CD40L) expression and naive/memory CD4(+) T cells].

AIM: To investigate the correlation between CD154(+) T cells, naive/memory CD4(+) T cell markers and cytokine expression. METHODS: PBMC from normal persons were isolated, stained by fluorescence-conjugated monoclonal antibodies of surface markers, intracellular cytokines and CD154, and analyzed at the single cell level by flow cytometer. RESULTS: After stimulated in vitro for six hours, CD154 were expressed on CD4(+) T cells, rather than on CD8(+) T cells. Analysis of the expression of CD45RA (marker for naive T cells) and CD45RO (marker for memory T cells) on CD154(+) T cells indicated that the majority of CD4(+) CD154(+) T cells were memory T cells. When stimulated by anti CD3 or anti CD3+anti CD28, the cells that produced IFN-gamma, IL-2 and TNF-alpha were CD4(+) CD154(+) and a single cell produced several cytokines simultaneously. In addition, CD4(+) CD154(+) T cells had low level or no expression of CD25 and they didn't express CD62L, but approximately fifty percent of the cells expressed CCR7. CONCLUSION: After stimulated in vitro for a short time and through further phenotypic and cytokine analysis, CD154, together with other cell surface markers and cytokines, can be used to discriminate between naive and memory CD4(+) T cells.