Dendritic cells in brain diseases

• Neuroinflammation induces the presence DC-like cells in the brain.
• DCs orchestrate innate and adaptive immune responses in brain diseases.
• DC responses are complex and disease-dependent.
• Modulation of DC responses and DC-based therapies are under investigation

Dendritic cells (DCs) are professional antigen presenting cells that constantly survey the environment acting as sentinels of the immune system, including in the CNS. DCs are strategically located near the cerebrospinal fluid, but they can potentially migrate to draining cervical lymph nodes either triggering immunogenic T cell responses or displaying tolerogenic functions. Under physiological conditions, the presence of DCs in the brain parenchyma is minimal but their numbers increase in neuroinflammation. Although DCs belong to a distinct immune cell lineage, they show various phenotypes and share certain common markers with monocytes, macrophages, and microglia. All these cells can express major histocompatibility complex class II, and acquire similar morphologies hampering their precise identification. Neuroinflammation is increasingly recognized in many brain disorders; here we review the literature reporting DCs in the inflamed brain in disease conditions and corresponding animal models of multiple sclerosis, stroke, brain tumors, Alzheimer's disease, Parkinson's disease, and epilepsy. This article is part of a Special Issue entitled: Neuro Inflammation edited by Helga E. de Vries and Markus Schwaninger.