Cytokine Response Is Determined by Duration of Receptor and Signal Transducers and Activators of Transcription 3 (STAT3) Activation

David A Braun,Miguel Fribourg,Stuart C Sealfon

doi:10.1074/jbc.m112.386573

Abstract

Paradoxically, the pro-inflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10 both activate STAT3, yet generate nearly opposing cellular responses. Here, we show that the temporal pattern of STAT3 activation codes for the specific cytokine response. A computational model of IL-6 and IL-10 signaling predicted that IL-6 stimulation results in transient activation of STAT3, with a rapid decline in phosphorylation and nuclear localization. In contrast, simulated IL-10 signaling resulted in sustained STAT3 activation. The predicted STAT3 patterns produced by each cytokine were confirmed experimentally in human dendritic cells. Time course microarray studies further showed that the dynamic genome-wide transcriptional responses were nearly identical at early time points following stimulation (when STAT3 is active in response to both IL-6 and IL-10) but divergent at later times (when STAT3 is active only in response to IL-10). Truncating STAT3 activation after IL-10 stimulation caused IL-10 to elicit an IL-6-like transcriptional and secretory response. That the duration of IL-10 receptor and STAT3 activation can direct distinct responses reveals a complex cellular information-coding mechanism that may be relevant to improving the prediction of the effects of drug candidates using this mechanism.

Highlights

Interleukin-6 and interleukin-10 both activate the same signaling mediator, STAT3, yet generate nearly opposing responses
Model stability to global parameter variation was tested by randomly selecting values for each parameter over a 106 range and determining whether the simulation produced distinct STAT3 activation responses to IL-6 and IL-10
IL-10, in contrast, produced a sustained STAT3 phosphorylation that reached peak levels after ϳ20 min and remained well above base line for the entire 2-h period of study. These results indicate that, as predicted by the model, the duration of STAT3 activation elicited by IL-6 and IL-10 signaling has a distinct temporal dynamics for each cytokine that is conserved for different concentrations

Summary

Background

Interleukin-6 and interleukin-10 both activate the same signaling mediator, STAT3, yet generate nearly opposing responses. The pro-inflammatory cytokine IL-6 and the anti-inflammatory cytokine IL-10 both activate STAT3, yet generate nearly opposing cellular responses. That the duration of IL-10 receptor and STAT3 activation can direct distinct responses reveals a complex cellular information-coding mechanism that may be relevant to improving the prediction of the effects of drug candidates using this mechanism. Interleukin-6 (IL-6) and interleukin-10 (IL-10) both regulate the same signaling molecule, STAT3, yet generate different cellular responses. Paralleling its discordant role in mediating IL-6 and IL-10 responses, STAT3 has been considered both an important pro-inflammatory regulator of the tumor microenvironment [7,8,9] and a key anti-inflammatory mediator of tumor immune evasion [10]. Explaining how activation of the same signaling molecule can paradoxically be both inflammatory and anti-inflammatory is important for clarifying the mechanism of STAT3-related malignancies and immunological diseases and facilitating therapeutic drug discovery in this area

EXPERIMENTAL PROCEDURES

RESULTS

DISCUSSION