Differential modulation of T helper type 1 (Th1) and T helper type 2 (Th2) cytokine secretion by prostaglandin E2 critically depends on interleukin-2.
Prostaglandin E2 (PGE2) favors T helper type 2 (Th2)-like cytokine secretion profiles in murine and human CD4+ T cells by inhibiting the production of the Th1-associated cytokines interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) and up-regulating the production of the Th2-associated cytokines IL-4 and IL-5 in a dose-dependent way. However, the potent inhibition of IL-2 production by PGE2 seems to be in contrast with the simultaneous up-regulation of IL-4 and IL-5 production, because the induction of these cytokines requires IL-2. We, therefore, investigated to which extent the net modulatory effect of PGE2 is determined by the availability of IL-2. To this aim, we examined the effects of PGE2 on the cytokine secretion profiles of a panel of human Th0 clones upon stimulation via different activation pathways, resulting either in high or low IL-2 production. The differential modulation of Th1 and Th2 cytokines by PGE2 was observed only upon modes of stimulation resulting in high IL-2 production. When IL-2 production was low, PGE2 inhibited the secretion of all four cytokines. These different modulation patterns were directly related to the IL-2 availability, because (i) neutralizing antibody to IL-2 abrogated the up-regulatory effect of PGE2 on IL-4 and IL-5 secretion in experiments with high endogenous IL-2 levels, (ii) lack of differential cytokine modulation by PGE2 in conditions with low levels of endogenous IL-2 could be restored with exogenous IL-2, and (iii) cell viability was comparable in all conditions. These results demonstrate that the net modulatory effect of PGE2 on the cytokine secretion profile of T cells critically depends on the availability of IL-2. Since this parameter varies with the experimental conditions and the T cell population studied, this finding may explain why certain immune responses may be either up- or down-regulated by PGE2 under different conditions.
Hilkens
C M
CM
Department of Cell Biology and Histology, University of Amsterdam, The Netherlands.
Vermeulen
H
H
van Neerven
R J
RJ
Snijdewint
F G
FG
Wierenga
E A
EA
Kapsenberg
M L
ML
D000818:Animals; D002999:Clone Cells; D016207:Cytokines / Q000096:biosynthesis*; D015232:Dinoprostone / Q000502:physiology*; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis / Q000502:physiology; D015847:Interleukin-4 / Q000096:biosynthesis; D015848:Interleukin-5 / Q000096:biosynthesis; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D018417:Th1 Cells / Q000276:immunology*; D018418:Th2 Cells / Q000276:immunology*
D016207:Cytokines; D007376:Interleukin-2; D015848:Interleukin-5; D015847:Interleukin-4; D007371:Interferon-gamma; D015232:Dinoprostone