Volume 6 Issue 12, December 2006

Antigen-specific T-cell responses are often characterized by the preferred use of certain T-cell receptors (TCRs). This Review describes when and how this might occur, with particular focus on the structural constraints that determine binding of a TCR to its ligand.

Toll-like receptors (TLRs) have an important role in the initiation of innate immunity following infection with protozoans. Here the activation of TLRs by protozoan components is described and TLR-based strategies to prevent or treat disease are discussed.

Fine tuning of immunity is achieved through numerous mechanisms: chemokine sequestration by non-signalling chemokine 'decoy' receptors is one example. This Review describes the chemokine decoy receptors that have evolved in both humans and viruses to elude chemokine activities and divert leukocyte recruitment.

Recent studies of the expression patterns and intracellular locations of individual SNARE proteins, which control membrane-fusion events involved in intracellular trafficking, have begun to shed light on their functions in immune responses, including the secretion of immune mediators, phagocytosis and the formation of immunological synapses.

Generating an effective AIDS vaccine remains a high priority. Are we any closer to reaching this goal? How might we overcome virus variability and generate a vaccine that elicits protective humoral and cellular immune responses at mucosal surfaces as well as systemically?

Perforin is crucial for inducing the death of infected or transformed cells by cytotoxic lymphocytes. Clues to its mechanism of action and role in immune homeostasis have been gained from analysis of patients with a severe immunodeficiency disorder that is due to perforin mutations.

The importance of T helper 2 cells in asthma has long been known. Now, new evidence indicates that invariant natural killer T cells might have a distinct and crucial role in the development of asthma.