Volume 14 Issue 3, March 2014

Programmed cell death 1 has a regulatory role in the antigen response by CD4⁺effector T cells.

Components of the unfolded protein response regulate CD8α⁺dendritic cell function and plasma cell survival.

Intestinal CX₃CR1⁺ macrophages can transfer processed antigen to CD103⁺DCs through gap junctions for the induction of oral tolerance.

A unique population of memory T_Regcells resides in healthy human skin.

Vitamin A deficiency shifts the balance of innate lymphoid cell subsets in the gut.

Pallaschet al. report an important mechanism through which therapeutic antibodies can induce tumour cell death, and they give an insight into how resistance can develop and be overcome.

T helper cells producing IL-9 have been identified in healthy and psoriatic human skin.

Antibiotics can promote allergy by leading to the outgrowth of commensal fungi.

Intestinal epithelial cells (IECs) promote gut homeostasis by coordinating the segregation and regulation of commensal microorganisms and the host immune system. This Review highlights the diverse and multifaceted roles of IECs in barrier function, and in their regulation of innate and adaptive immune cell function and homeostasis in response to microbial colonization.

Regulatory T (T_Reg) cells are crucial for maintaining immune homeostasis in the body, with recent data showing that distinct T_Reg cell subsets become specialized to function in different tissues. Here, Liston and Gray highlight the need to regulate the number and function of the T_Reg cells themselves, and they describe the dynamic processes that achieve this homeostasis and functional specialization of T_Regcell subsets.

The removal of apoptotic cells by phagocytes is essential for the maintenance of tissue homeostasis and is usually immunologically silent. However, dysregulation of this process is associated with numerous inflammatory and autoimmune diseases, and thus the therapeutic manipulation of apoptotic cell clearance by phagocytes may be a means to treat these diseases.

The immune regulation of liver fibrosis (particularly the distinct and opposing roles of macrophage subsets) provides an informative model of the endogenous mechanisms that mediate the resolution of fibrosis and the restoration of tissue homeostasis.

Extracellular vesicles, including exosomes, provide a means of intercellular communication for immune regulation. Here, the authors describe how the proteins, nucleic acids and other molecules that they carry influence immune responses, and explore their potential use in the treatment of inflammatory and autoimmune diseases, and cancer.

The homeostatic immune responses that operate in steady-state conditions are required to maintain the stability of diverse physiological systems and processes, ranging from host–commensal relationships in the gut to the fibrotic cascade involved in wound healing. Furthermore, regulatory T cells and phagocytic cells are required to maintain homeostasis of all tissues. Failure of these homeostatic mechanisms can precipitate disease in the absence of infection.