CD8(+) T cells in Leishmania infections: friends or foes?

Host protection against several intracellular pathogens requires the induction of CD8(+) T cell responses. CD8(+) T cells are potent effector cells that can produce high amounts of pro-inflammatory cytokines and kill infected target cells efficiently. However, a protective role for CD8(+) T cells during Leishmania infections is still controversial and largely depends on the infection model. In this review, we discuss the role of CD8(+) T cells during various types of Leishmania infections, following vaccination, and as potential immunotherapeutic targets.