The CpG PAMP is recognized by the pattern recognition receptor (PRR) Toll-Like Receptor 9 (TLR9), which is constitutively expressed only in B cells and plasmacytoid dendritic cells (pDCs) in humans and other higher primates.
The trachea is an important structure within your respiratory system, which is the organ system that delivers oxygen to your bloodstream. The trachea is a rigid tube that conducts air from your larynx to your bronchi. The trachea's rigidity is maintained by a series of cartilaginous rings arranged along its length called C-shaped cartilage rings.
The trachea, also known as windpipe, is a strong muscular tube located in front of the esophagus. It connects the nose and mouth to the lungs. It is an important part of the respiratory system. At the lower end, it splits into the left and right bronchi that enter into the lungs.