Schwann cells as putative safe host cells for Leishmania amazonensis

A hallmark of Leishmania infection is the invasion of tissue macrophages by the parasite as an essential step for the establishment of parasitism. In fact, macrophages are considered the most important host cell for Leishmania parasites, although several other cell types are able to endocytose Leishmania in vitro or in vivo. Previous data published by our and other groups support the notion that Schwann cells (SCs) act as a putative host cell for Leishmania infection. In this context, we hypothesized that SCs, abundant in highly innervated skin, might form a less hostile environment for Leishmania than macrophages and, thus, enable the persistence of the parasite. We evaluated the infection of a human SC line (ST88-14) by promastigotes of Leishmania amazonensis (LA) and also the potential effect of infection on nitric oxide (NO) production by these cells. The ST88-14 SC line represents a good model for our study because these cells express some phenotypical markers of normal SCs. ST88-14 cells (generously donated by Jonathan Fletcher, Dana Farber Cancer Institute, Boston, USA) were isolated from a patient with neurofibromatosis type 1. LA (MHOM/BR/