Figure 3: Schwann cells displaying TLR1 602I and TLR2 are stimulated by the M. leprae 19 kDa lipoprotein to commence programmed cell death. Damage to peripheral nerves, by either direct infection or inflammatory ischemia, induces TLR1 expression which, in combination with TLR2 and mycobacterial products, can amplify apoptotic signals. Upregulation of TLR1 from damage caused by either direct infection or inflammatory ischemia could predispose nerves to further injury, resulting in classical leprosy anesthesis. Cells expressing the trafficking-deficient TLR1 602S may resist this mechanism of nerve damage.