Sentinel cell

Sentinel cells refer to cells in the body's first line of defense, which embed themselves in tissues such as skin. Sentinel cells represent diverse array of cell types with the capability to monitor the presence of exogenous or potentially harmful particles and play a crucial role in recognizing and sampling signs of infection or abnormal cellular activity and/or death. Encountering such stimuli is initiating the innate immune response. Their ability to recognize injurious or dangerous material is mediated by specialized pattern recognition receptors (PRR) and possess specialized function to prime naive T cells upon pathogen recognition.

Sentinel cells can refer to specific antigen-presenting cells, such as:

• Macrophages
  • Kupffer cells - in the liver
  • Langerhans cells - in the skin and mucosa (*these are a form of dendritic cells)
  • Alveolar macrophages - in the lungs
  • Microglia - in the brain
• Dendritic cells

Sentinel cells can also refer to cells that are normally not specialized antigen-presenting cells such as:

• Mast cells
• Specialized T cells

Sometimes tissue cells not part of the immune system such as are also referred to as Sentinel cells:

• Fibroblasts
• Epithelial cells