Midgut membrane-bound glycoprotein Bm86 (Bm86) (Bm86)

Bm86 is a membrane-bound glycoprotein located on the surface of midgut enterocytes in the cattle tick, Rhipicephalus microplus (UniProt P12620). It is characterized as a "hidden antigen" because it is not naturally exposed to the host immune system during the tick feeding process (Willadsen et al., 1989). The protein contains multiple epidermal growth factor (EGF)-like domains and is anchored to the cell membrane via a glycosylphosphatidylinositol (GPI) anchor (Richardson et al., 1993). When cattle are immunized with recombinant Bm86, they produce high titers of specific antibodies. Upon ingestion of the blood meal, these antibodies bind to the Bm86 protein on the tick gut wall, initiating a complement-mediated lysis of the enterocytes (Tellam et al., 1992). This damage results in the leakage of blood into the tick hemolymph, significantly reducing tick survival, weight gain, and reproductive capacity (de la Fuente et al., 2007). Bm86-based vaccines, such as Gavac and TickGARD, are used globally to manage tick populations and reduce the transmission of tick-borne pathogens like Babesia and Anaplasma species (Rodriguez et al., 1994). Despite its success, the efficacy of Bm86 vaccines can vary depending on the geographic strain of the tick, necessitating the search for conserved epitopes or regional variants (Garcia-Garcia et al., 2000).

Other names

Bm86 antigenRhipicephalus microplus Bm86Tick midgut glycoprotein Bm86

Induction of host-derived antibodies that bind to tick midgut enterocytes upon ingestion, leading to complement-mediated cell lysis and gut wall destruction.