Volume 13 Issue 9, September 2012

The characteristics of the tumor microenvironment vary widely. New work shows that after tumor-associated expression of the receptor TIM-3 by dendritic cells, TIM-3 inhibits the antitumor efficacy of DNA vaccines and chemotherapy by binding to the damage-associated molecular pattern molecule, HMGB1.

The activation of T cells requires the entry of calcium ions through the plasma membrane. A study now identifies a voltage-gated sodium channel as being essential for the sustained entry of calcium needed for the developmental process of positive selection.

The mechanism by which γδ T cells are triggered to respond to stress elicited by infection or malignancy has remained a mystery. New data identify endothelial protein C receptor as a stress ligand for γδ T cells that is induced by cytomegalovirus infection.

Structural studies identify considerable differences in the recognition of CD1d-lipid complexes by the TCRs of type II and type I (invariant) natural killer T cells.

Sensors of the NLR family generally activate innate immunity. Ting et al., however, demonstrate that the little-known NLRC3 negatively regulates Toll-like receptor signaling by altering ubiquitination of the signaling adaptor TRAF6.

The receptor TIM-3 was initially identified as a negative regulator of T helper type 1 responses. Jinushi and colleagues now show it has high expression by tumor associated-dendritic cells, in which it perturbs immunogenic recognition of nucleic acids.

New-born and young mice are more susceptible to viral infections. Laouar and colleagues show this sensitivity is due in part to age-dependent TGF-β–mediated suppression of natural killer cell production.

Natural killer T cells (NKT cells) recognize lipid antigens presented by CD1d. Zajonc and Rossjohn and their colleagues describe molecular interactions between type II NKT cell antigen receptors and CD1d-ligand complexes, which demonstrate distinct modes of recognition used by the receptors.

Natural killer T cells (NKT cells) recognize lipid antigens presented by CD1d. Zajonc and Rossjohn and their colleagues describe molecular interactions between type II NKT cell antigen receptors and CD1d-ligand complexes, which demonstrate distinct modes of recognition used by the receptors.

Van Gisbergen and colleagues report that Hobit, a homolog of the transcription factor Blimp-1, controls the maintenance of mature mouse natural killer T cells and regulates their effector functions in a species-specific way.

How γδ T cells 'see' antigen is poorly defined. Déchanet-Merville and colleagues demonstrate that a subset of γδ T cells functionally recognize the stress-associated self molecule EPCR on both virus-infected and transformed cells.

Calcium signals are required for thymocyte positive selection. Allen and colleagues show that thymic selecting ligands induce SCN5a-SCN4b voltage-gated sodium channels and sustained calcium influx necessary for CD4⁺ selection.

The transcriptional regulation of commitment to the dendritic cell (DC) lineage and functional specialization of DCs in vivo is poorly understood. In this Resource, Merad and colleagues identify the lineage relationships among various tissue DC subsets.