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 or windpipe is secretory in nature, possessing many exocrine glands and being lined by a pseudostratified columnar epithelium in which ciliated and mucous cells predominate.The ciliated epithelial cells are interspersed with goblet mucosal cells which are covered by microvilli.he trachea or windpipe is secretory in nature, possessing many exocrine glands and being lined by a pseudostratified columnar epithelium in which ciliated and mucous cells predominate.