NALP inflammasomes: a central role in innate immunity

COPs and POPs: modulators of inflammasome activity

Inflammasomes represent molecular platforms for the activation of inflammatory caspases and are essential for processing and secretion of the inflammatory cytokines IL-1beta and IL-18. Multiple key proteins of inflammasomes contain caspase recruitment domains (CARDs) or pyrin domains (PYDs). Dissecting CARD- and PYD-mediated interactions substantially improved our understanding of the mechanisms by which these protein platforms are activated and emphasized their essential role during the inflammatory cytokine response. However, their precise regulation is still poorly understood. A family of small proteins that are composed of either a CARD or a PYD only emerged as important inflammasome regulators. These CARD-only proteins (COPs) and PYD-only proteins (POPs) function as endogenous dominant negative proteins that modulate the activity of inflammasomes in response to pathogen infection and tissue destruction. In this review we will summarize the most recent advances in the regulation of inflammasomes and highlight their importance for immunity and inflammatory disease.

Microarray-based identification of novel biomarkers in IL-1-mediated diseases

Interleukin 1b (IL-1b) is emerging as mediator of a wide range of human diseases. Availability of IL-1 blockers that result in clinical benefits to patients with these diseases is creating a demand for biomarkers to diagnose as well as to predict and follow responses to therapy. Blood gene expression profiling can be used to identify such biomarkers. This review will summarize recent studies in the field and will discuss some of the challenges raised by the use of this technology in biomarker discovery.

Detection of immune danger signals by NALP3

The innate immune system in animals has been forged to detect microbes, coordinate symbiotic responses, and mount immune defenses against pathogens. Recently, innate immunity was shown to detect signals released by damaged cells or tissues such as uric acid or ATP. These danger signals were proposed to be important in promoting and regulating inflammation upon trauma or pathogen insults. The physiological relevance of these signals in the immune response and their mechanisms of action are still unclear. Recent findings suggest that some danger signals activate the NALP3 inflammasome, an innate immune complex that controls inflammatory caspases and IL-1 activation.