Insulin resistance is a feature of most patients with type 2 diabetes mellitus. Epidemiological evidence suggests a correlation between inflammation and insulin resistant states such as obesity, but the underlying mechanisms are largely unknown. Interleukin-1 receptor-associated kinases (IRAK) play a central role in inflammatory responses by regulating the expression of various inflammatory gen...

Most members of the Toll-like receptor (TLR) and interleukin-1 receptor (IL-1R) families transduce signals via a canonical pathway involving the MyD88 adapter and the interleukin-1 receptor-associated kinase (IRAK) complex. This complex contains four molecules, including at least two (IRAK-1 and IRAK-4) active kinases. In mice and humans, deficiencies of IRAK-4 or MyD88 abolish most TLR (except...

Host immune responses are finely regulated by the opposing effects of Th17 and T regulatory (Treg) cells. Treg cells help to dampen inflammatory processes and Th17 cells facilitate various aspects of immune activation. The differentiation of Th cells depends on a unique combination of stimulants and subsequent activation of diverse transcription factors. In particular, cooperative activation of...

Recent in vitro and murine in vivo studies have identified several potential LPS tolerance factors. In this study, we describe the expression kinetics of these LPS tolerance factors in standardized human endotoxemia models using i.v. LPS bolus administration. Responsiveness to LPS as well as the expression of potential regulators of LPS signaling were determined in peripheral whole blood. Intra...

OBJECTIVE Effective postinfarction repair requires timely suppression of innate immune signals to prevent the catastrophic consequences of uncontrolled inflammation on cardiac geometry and function. In macrophages, interleukin-1 receptor-associated kinase (IRAK)-M acts as a functional decoy preventing uncontrolled toll-like receptor /interleukin-1-mediated responses. Our study investigates the ...

Although blood monocytes possess significant cytotoxic activity against tumor cells, tumor-infiltrating monocytes are commonly deactivated in cancer patients. Monocytes pre-exposed to tumor cells show significantly decreased expression levels of TNF-alpha, IL-12p40, and IL-1R-associated kinase (IRAK)-1. Activation of the Ser/Thr kinase IRAK-1 is an important event in several inflammatory proces...

As a part of the negative feedback mechanism, CpG DNA induces IRAK-M expression in monocytic cells. In the present study we investigated a biochemical signaling pathway and the transcription factors responsible for CpG DNA-mediated Irak-m gene expression. CpG DNA-induced Irak-m expression did not require new protein synthesis and was regulated at the transcriptional level through an endosomal p...

Toll-like receptors (TLR) are expressed by a variety of cancers, including melanoma, but their functional contributions in cancer cells are uncertain. To approach this question, we evaluated the effects of stimulating or inhibiting the TLR/IL-1 receptor-associated kinases IRAK-1 and IRAK-4 in melanoma cells where their functions are largely unexplored. TLRs and TLR-related proteins were variabl...

BACKGROUND The innate immune system greatly contributes to the inflammatory process after myocardial infarction (MI). Interleukin-1 receptor-associated kinase-4 (IRAK-4), downstream of Toll/interleukin-1 receptor signaling, has an essential role in regulating the innate immune response. The present study was designed to determine the mechanism by which IRAK-4 is responsible for the cardiac infl...

Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Recent studies have revealed that Toll-like receptor (TLR)-initiated immune response to Brucella spp. depends on myeloid differentiation factor 88 (MyD88) signaling. Therefore, we decided to study the role of the interleukin-1 receptor-associated kinase 4 (IR...