Review Articles in 2011

Much insight into the workings of the immune system has been garnered from studying patients with primary immunodeficiencies. This article describes the recent discovery of human dendritic cell deficiencies and explains the lessons we can learn from these syndromes.

Ultraviolet radiation from sunlight can modulate immune function by both vitamin D-dependent and -independent mechanisms. The authors discuss the implications of this for understanding whether vitamin D supplementation might benefit patients with autoimmune diseases and allergic asthma, and boost immunity to pathogens.

The beneficial impact of exercise on health is indisputable. Here, the authors review the direct and indirect anti-inflammatory effects of exercise and discuss the potential mechanisms involved.

This Review provides an overview of the multiple functions of neutrophils in the immune system. Although classically considered simply as 'first responders', it is now clear that neutrophils contribute to the activation and polarization of numerous cells of both the innate and adaptive immune systems and are important players in the pathogenesis of many diseases.

Recent thymic emigrants (RTEs) are a population of T cells that undergo maturation in the periphery and are functionally distinct from mature naive T cells. These cells constitute a major proportion of the T cell pool in neonates and in adults recovering from lymphoablation. This article describes what is known, and what remains to be discovered, about RTEs.

Alan Rothman describes the types of immune response that are associated with protection and pathology during dengue virus infection. Although virus-specific antibodies provide protective neutralizing immunity, they can also facilitate infection of other host cells; the author discusses the implications of this for vaccine development.

This article looks at recent developments in our understanding of protective immune mechanisms againstStaphylococcus aureusskin infections, with a focus on IL-1- and IL-17-mediated responses, and the impact of these new discoveries on future immunotherapy and vaccination strategies.

T cell progenitors must receive cues to instruct their homing to and entry into the thymus and, once there, positive and negative selection signals need to be synchronized with signals that control the migration of thymocytes within and out of the thymus. This Review focuses on recent advances in our understanding of thymocyte migration and highlights some outstanding questions.

In the intestine, intraepithelial lymphocytes (IELs) maintain the integrity of the epithelial barrier and provide protection against pathogens. However, IELs may also drive immunopathological responses in patients with coeliac disease or inflammatory bowel disease. Here, the authors discuss the 'light' and 'dark' sides of the intestinal IELs.

The development of immune cells is tightly regulated by a series of epigenetic mechanisms. Here, Howard Cedar and Yehudit Bergman discuss the different types of chromatin modifications that determine the fate of haematopoietic stem cells.

TRAF3 is a central component of the TNF and TLR signalling pathways. This Review summarizes the current knowledge on TRAF3-mediated regulation of MAPK and alternative NF-κB pathways and of the type I interferon response in immune cells.

Exciting new studies have uncovered many of the molecules and cell types that contribute to 'type 2' immune responses. Here, Judith Allen and Rick Maizels discuss how these responses are generated and provide protective immunity during helminth infection.

Mitochondria are emerging as important players in innate immunity: they act as signalling platforms for antiviral molecules, produce reactive oxygen species that influence both antiviral and antibacterial immune responses and are a source of factors that initiate sterile inflammation.

Integrins are molecules with dynamic structure that are expressed by all leukocytes. This Review discusses the current knowledge on how these surface molecules integrate intracellular and environmental signals and modify their structure, thereby contributing to the activation and migration of T cells.

It is well appreciated that sphingosine-1-phosphate (S1P) and its receptors have important roles in controlling lymphocyte migration. This Review discusses the emerging evidence that S1P is involved in other immune responses and considers the clinical implications of this.

Interleukin-7 (IL-7) induces T cell proliferation and enhances antigen-specific immune responses: attributes that pinpoint its value as a potential therapeutic agent. This Review summarizes preclinical and clinical data on the immunorestorative effects of IL-7 in various pathologies and discusses the conditions for which IL-7 therapy might be of use.

This Review describes the anatomical features of the central nervous system (CNS) barriers and focuses on the way in which the immune system responds to neurotropic viruses that establish latent or persistent infections in the CNS. It also discusses imaging technologies that can be used to understand viral entry and antiviral immune responses in the CNS.

Here, Thomas Boehm considers the commonalities that underlie the adaptive immune systems of jawless and jawed vertebrates, including functionally distinct B- and T-like cells and anatomically segregated sites for their generation, as well somatically diversified and clonally expressed antigen receptors. The features that distinguish the adaptive immune systems in these vertebrate groups are also considered.

The improvement of tuberculosis diagnosis and treatment regimens depends on the identification of suitable biomarkers. Analysis of host immunological markers at diagnosis and throughout treatment may aid new drug development and the clinical management of individual patients.

Platelets are well known as mediators of haemostasis, but their roles in immunity are less well appreciated. Here, the authors relate the diverse immune functions of platelets and discuss how these anucleate cells can promote both innate and adaptive immune responses.