Outer surface protein C (OspC)

Outer surface protein C (OspC) is a 23-kDa lipoprotein expressed on the surface of Borrelia burgdorferi, the primary causative agent of Lyme disease (UniProt P0CL66). It plays a critical role in the life cycle of the spirochete, specifically during the transition from the tick vector to the mammalian host (PubMed: 15103034). OspC expression is induced during tick feeding, and the protein is essential for the bacteria to migrate from the tick midgut to the salivary glands and subsequently infect the host (PubMed: 15505200). Once inside the mammal, OspC helps the bacteria evade the initial innate immune response and establish an early infection by binding to host factors like plasminogen and tick salivary proteins like Salp15 (PubMed: 11081860, PubMed: 15845853). Because of its surface exposure and essentiality for infection, OspC is a primary candidate for second-generation Lyme disease vaccines and serves as a key diagnostic marker in serological assays (PubMed: 24501115). However, the high degree of sequence polymorphism among different Borrelia strains presents a significant challenge for developing a universal vaccine (PubMed: 16461669).

Other names

OspCp23Outer surface lipoprotein C23 kDa antigen

Neutralization of the protein prevents the spirochete from migrating from the tick midgut to the salivary glands and inhibits the establishment of infection in the mammalian host.