Virulence-associated protein V (LcrV)

Virulence-associated protein V (LcrV), commonly known as V antigen, is a multifunctional virulence factor found in Yersinia pestis and other Yersinia species, serving as a critical component of the bacterial type III secretion system (T3SS)[1][3][8]. LcrV is required for the assembly and function of the T3SS injectisome, mediates secretion and translocation of effector proteins (Yops) into host cells, modulates host immune responses (including cytokine regulation), and is necessary for full virulence of Y. pestis—the causative agent of plague[1][3][7][8]. Structurally, LcrV forms the tip of the T3SS needle, has a unique fold with helical and coiled-coil motifs, and is secreted during infection[4][8]. Because of its central role in pathogenesis and ability to elicit protective immunity, LcrV is a major focus of subunit vaccine development, and anti-LcrV antibodies can block Yop translocation, thereby conferring protection against plague and potentially other Gram-negative infections featuring homologous systems[3][6][9]. Natural sequence polymorphisms exist, but the protein is generally conserved across epidemic strains of Y. pestis[2]. There are no licensed drugs that directly target LcrV, but several vaccines in development use LcrV or its derivatives as immunogens.

Other names

V antigenVirulence-associated V antigenType III secretion system tip protein

Inhibition of effector translocation by antibody binding, Immunomodulation leading to protection against Yersinia infection