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

To investigate the correlation between CD154(+) T cells, naive/memory CD4(+) T cell markers and cytokine expression.

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.

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.

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.