ILT2 and ILT4 Drive Myeloid Suppression via Both Overlapping and Distinct Mechanisms.

Solid tumors are dense three-dimensional (3D) multicellular structures that enable efficient receptor-ligand trans interactions via close cell-cell contact. Immunoglobulin-like transcript (ILT)2 and ILT4 are related immune-suppressive receptors that play a role in the inhibition of myeloid cells within the tumor microenvironment. The relative contribution of ILT2 and ILT4 to immune inhibition in the context of solid tumor tissue has not been fully explored.

C17 prevents inflammatory arthritis and associated joint destruction in mice.

C17 was first described about ten years ago as a gene expressed in CD34+ cells. A more recent study has suggested a role for C17 in chondrogenesis and development of cartilage. However, based on sequence analysis, we believe that C17 has homology to IL-2 and hence we present the hypothesis that C17 is a cytokine possessing immune-regulatory properties.

IL-33, an interleukin-1-like cytokine that signals via the IL-1 receptor-related protein ST2 and induces T helper type 2-associated cytokines.

Cytokines of the interleukin-1 (IL-1) family, such as IL-1 alpha/beta and IL-18, have important functions in host defense, immune regulation, and inflammation. Insight into their biological functions has led to novel therapeutic approaches to treat human inflammatory diseases. Within the IL-1 family, IL-1 alpha/beta, IL-1Ra, and IL-18 have been matched to their respective receptor complexes and have been shown to have distinct biological functions.

The CD200 receptor is a novel and potent regulator of murine and human mast cell function.

CD200R is a member of the Ig supergene family that is primarily expressed on myeloid cells. Recent in vivo studies have suggested that CD200R is an inhibitory receptor capable of regulating the activation threshold of inflammatory immune responses. Here we provide definitive evidence that CD200R is expressed on mouse and human mast cells and that engagement of CD200R by agonist Abs or ligand results in a potent inhibition of mast cell degranulation and cytokine secretion responses.