Figure 5.

Possible mechanism for Fas/FasL-mediated apoptosis leading to keratinocyte death and ulceration during CL. Keratinocytes up-regulate Fas as a result of the inflammatory reaction surrounding L. major-infected macrophages. FasL-expressing T cells and macrophages accumulate at the site of L. major infection. The Fas-FasL or Fas-sFasL interaction will lead to keratinocyte apoptosis and ulceration as well as to activation-induced T-cell apoptosis. Macrophages are quite resistant against FasL-mediated apoptosis.42