Mechanisms of the borrelia to evade the immune system.

• Borrelia are recognized by immune cells through TLR2 and CD14 and attacked by complement and antibodies (upper row).
• Therefore (lower row), the borrelia downregulate their surface proteins,
• hide in the extracellular matrix, and
• use immune suppression, i.e.
  • complement-neutralizing proteins like Salp, CRASPs, or ISAC/IRAC or
  • induce the formation of immune complexes by secreting soluble antigens
  to be protected from recognition and subsequent killing.