The type of neuroglia cell which is derived from monocyte and mediates immune response in CNS is

Microglia are a type of neuroglia located throughout the brain and spinal cord. They are derived from monocytes (mesodermal origin) and act as the first and main form of active immune defense in the central nervous system (CNS).

Astrocytes are star-shaped glial cells of ectodermal origin involved in forming the blood-brain barrier and providing structural support.

Satellite cells and Schwann cells are glial cells of the peripheral nervous system (PNS).

Answer: microglia cell