Bm86 glycoprotein (Bm86)

Bm86 is a membrane-bound glycoprotein primarily expressed on the surface of midgut enterocytes in the cattle tick, Rhipicephalus microplus (UniProt: P23623). It is characterized by the presence of multiple epidermal growth factor (EGF)-like domains and is anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor (Tellam et al., 1992). While its exact physiological role remains partially elusive, it is believed to be involved in cell-cell interactions or the endocytosis of blood meal components during tick feeding. Bm86 serves as the primary antigen in the first commercially available vaccines against ectoparasites, such as Gavac and TickGARD (de la Fuente et al., 2007). When a tick feeds on a vaccinated host, it ingests specific anti-Bm86 antibodies that bind to the gut lining, causing significant damage to the tick's digestive tract through complement-mediated lysis or physical disruption. This damage reduces the tick's ability to engorge and lay eggs, ultimately decreasing the tick population and the transmission of tick-borne diseases like bovine babesiosis and anaplasmosis (Willadsen, 2004). The efficacy of Bm86-based vaccines can vary significantly depending on the geographic strain of the tick, which remains a primary challenge in its global application.

Other names

Bm86 antigenRhipicephalus microplus Bm86Tick midgut glycoprotein Bm86BM86_RHIMI

Induction of host antibodies that, upon ingestion by the tick during a blood meal, bind to the Bm86 glycoprotein on the surface of midgut enterocytes, leading to complement-mediated lysis or physical disruption of the gut wall, which impairs tick feeding, survival, and fecundity (Willadsen, 2004).