Borrelia burgdorferi VlsE

Borrelia burgdorferi VlsE, or Variable Major Protein-Like Sequence E, is the core molecule for bacterial antigen variation and long-term immune escape. Encoded by the vls gene family (with one expression site vlsE and multiple silent sites), the bacterium uses gene recombination to integrate silent site sequences into vlsE, causing high-frequency amino acid sequence variation in VlsE. When the host produces antibodies against the current VlsE, the bacterium generates a new subtype via variation, making the old antibodies ineffective, enabling chronic infection. Its variation mechanism is a research focus, and its conserved regions are used as specific markers for chronic Lyme disease diagnosis.