E. Hagiwara et al., PHENOTYPE AND FREQUENCY OF CELLS SECRETING IL-2, IL-4, IL-6, IL-10, IFN AND TNF-ALPHA IN HUMAN PERIPHERAL-BLOOD, Cytokine, 7(8), 1995, pp. 815-822
The phenotype and frequency of cells in normal human peripheral blood
spontaneously secreting IL-2, IL-4, IL-6, IL-10, IFN and TNF-alpha ex
vivo was determined using ELIspot assays, CD4(+) T cells were the domi
nant source of IL-2 and IL-4 while multiple cell types (primarily CD8(
+) lymphocytes) produced IFN. Fewer than 0.05% of mononuclear cells we
re spontaneously secreting these T cell derived factors. By comparison
, IL-6, IL-10 and TNF-alpha were produced by 0.7-20% of PBMC. The prim
ary sources of the latter cytokines were CD14(+) macrophages/monocytes
. A significant positive correlation was found in the frequency of cel
ls secreting IL-6, IL-10 and TNF-alpha ex vivo, suggesting that the re
lease of such factors was coordinately regulated, No such correlation
was found among IL-2, IL-4 and IFN secreting cells, indicating that th
e production of predominantly T cell derived cytokines was regulated i
ndependently.