Major basic proteins are produced by?

Eosinophils have a granule that contains major basic protein (MBP) Proteoglycan 2, (natural killer cell activator, eosinophil granule major basic protein), also known as PRG2, is a protein which in humans is encoded by the PRG2 gene. It is a potent enzyme against helminths. The eosinophil major basic protein also causes the release of histamine from mast cells and basophils and activates neutrophils and alveolar macrophages.