Review Articles in 2012

B cells are unique in their ability to link the innate and adaptive immune systems owing to their expression of both an antigen-specific B cell receptor (BCR) and pattern-recognizing Toll-like receptors (TLRs). This article focuses on the role of dual BCR and TLR signalling in fine-tuning B cell responses, with a particular emphasis on B cell-intrinsic events.

This article reviews the interplay between innate and adaptive immune cells in the response to viral infection of the lower respiratory tract and describes the fine-tuning mechanisms that control antiviral T cells in the lungs but that can also predispose an individual to subsequent pulmonary bacterial infections.

The tolerogenic properties of the liver make it an attractive site for infection by pathogens. This Review describes how most pathogens are effectively controlled by immune responses in the liver, and how some pathogens, such as hepatitis viruses and malaria-causing parasites, can establish chronic infections in the liver.

Here, the authors discuss the biological role of interleukin-2 (IL-2) in the immune system, focusing on recent advances in our understanding of how IL-2 signals have different effects on various T cell populations and how this knowledge can be harnessed in the clinic.

The authors use flow cytometry of peripheral blood mononuclear cells as an example to outline the approaches to assay standardization that will be required to realize the full potential of immunophenotyping as a research tool and in the clinic.

How are regulatory T (T_Reg) cells selected in the thymus? What is the role of T cell receptor specificity in the generation of self antigen-specific T_Reg cells? What is the involvement of thymic antigen-presenting cells in T_Reg cell differentiation and how is FOXP3 expression induced in developing thymocytes? Here, the authors summarize the latest findings in the field of T_Regcells to provide answers to these long-standing questions.

Toll-like receptors (TLRs) have a central role in the initiation of innate and adaptive immune responses. Recent studies have shown that various accessory molecules are required for the biosynthesis and/or activation of several TLRs. A detailed knowledge of these accessory molecules is necessary to better understand the function of TLRs in the immune system.

This Review article looks at how the features of vertebrate adaptive immunity — specificity, self-tolerance and memory — can be achieved in plants through different immune strategies.

The dendritic cell (DC) network consists of several DC subsets with distinct functions. Here, Gabrielle Belz and Stephen Nutt focus on transcription factors that regulate DC lineage specification in response to developmental and environmental cues.

Immunity to viruses is typically associated with the development of cytotoxic CD8⁺ T cells. However, CD4⁺ T cells are also important for protection during viral infection. Here, the authors describe the various ways in which different CD4⁺T cell subsets can contribute to the antiviral immune response.

Allergic contact dermatitis is a common skin disease that is driven by an inappropriate immune response to innocuous environmental antigens. This Review focuses on how the early immune mechanisms that are triggered in response to contact allergens promote subsequent disease development.

Type I interferons (IFNs) have become synonymous with antiviral immunity. But, as discussed in this Review, type I IFNs also have roles in bacterial infections, in intestinal homeostasis and in inflammatory and autoimmune diseases.