Research Highlights in 2019

Commensal bacteria at mucosal surfaces can remotely control the thymic maturation of mucosal-associated invariant T cells through the production of microbial factors that enter the circulation and are taken up by thymic cells.

A new study shows that monocytes, recruited to the lungs during an infection, sense alterations in physical forces and pressure and initiate a pro-inflammatory response. This environmental sensory axis is mediated by the mechanically activated calcium channel PIEZO1.

Fasting can modulate immune responses in the context of infection, inflammatory disease and cancer.

The angiogenic growth factor placental growth factor is produced by T_H17 cells and induces T_H17 cell differentiation, which suggests a positive feedback loop between angiogenesis and autoimmunity in chronically inflamed tissues.

Class-switch recombination was thought to take place in B cells that enter germinal centres, but this study shows that it actually occurs earlier than previously thought.

Targeting metabolism via mTOR restores suppressor functions in FOXP3-deficient regulatory T cells.

Chimeric antigen receptor (CAR) T cells that secrete bispecific T cell engagers (BiTEs) show promise for the treatment of glioblastoma in mouse models.

Stimulation of cutaneous TRPV1⁺ neurons is sufficient to induce a type 17 inflammatory response that spreads to surrounding skin areas to provide ‘anticipatory’ host defence against fungal infection.

Metabolites associated with the maternal or neonatal microbiota can shape regulatory T cell development in early life, thereby affecting the susceptibility of infants to allergy.

Researchers have identified a subset of T helper cells that is found predominantly in individuals with multiple sclerosis. The subset is defined by expression of GM-CSF and CXCR4 and may be important in disease pathology.

Plasma cells promote increased myelopoiesis in the bone marrow of older mice.

Leukaemia stem cells seem to evade immune surveillance by repressing the expression of stress-induced activating natural killer (NK) cell ligands. Overriding this repression with inhibitors renders them amenable to control by NK cells and prevents leukaemogenesis.

Cytosolic protein oligomers formed by certain innate immune receptors and their adaptor proteins trigger the integrated stress response pathway, which regulates the stability of these signalosomes as well as downstream inflammatory responses.

A new study shows that neutrophils collaborate with tumour-associated macrophages and unconventional innate-like T cells to mount type 1 antitumour immunity.

This study demonstrates that TREM1, an amplifier of inflammation, is induced on peripheral myeloid cells in response to stroke and uncovers an intriguing connection between the brain, the gut and the immune system.

Six studies describe a role for TOX in promoting an ‘exhausted’ CD8⁺ T cell phenotype in settings of chronic antigenic stimulation, such as persistent viral infections and cancer.

Levels of CCR5 expression by CD4⁺ T cells, which influence the outcome of HIV-1 infection, are modulated by polymorphism of a non-coding RNA that affects mRNA stability.

Trifunctional antibodies, binding to the natural killer cell receptors NKp46 and CD16, as well as a tumour antigen, show promising activity in preclinical experiments.

Antibodies that dissolve Charcot–Leyden crystals may have therapeutic potential in asthma and other eosinophil-associated inflammatory diseases.

A new study identifies an unexpected role for type I interferon-responsive CD8⁺ T cells in cachexia associated with viral infection.