Borrelia burgdorferi ospA

Borrelia burgdorferi ospA is essentially the same as OspA, with lowercase "ospA" representing the encoding gene and uppercase "OspA" the protein product. The ospA gene is on the bacterial linear plasmid, regulated by environmental signals (e.g., temperature, pH). In ticks (low temperature), it is highly expressed to synthesize OspA for colonization. When entering the host (≈37°C), its expression is inhibited to reduce OspA, avoiding recognition by host anti-OspA antibodies. Studying its regulatory mechanism helps understand the bacterium's environmental adaptation, and the encoded OspA remains an important target for Lyme disease prevention and diagnosis.