YBX3 and infection: However, our finding that limited exposure of DbpA and DbpB on the surface of cultured spirochetes does not suggest that the adhesins can not have a full access to their ligand decorin in mammalian tissues because OspA and OspB, which are abundantly produced in spirochetes grown in vitro but are downregulated to a baseline level during mammalian infection [28], may reduce the accessibility of DbpA and DbpB.