Macrophage supernatant infected with Leishmania major mediates the cytology of fibroblast cells in skin wounds

Objective: Healing of Cutaneous Leishmaniasis relies on the effective and modulates protective immune responses. Although the immune system is necessary to eliminate the parasite, it could be considered as the main cause of ulcers. Therefore, main aim of this study was to explore the possible regulatory functions of macrophage supernatant infected with Leishmania major on the fibroblast cells.

Materials and Methods: In this experimental study, different concentrations of infected macrophage supernatant extract (50, 100, 150, 200, and 250μg/mL) were tested at different times (6, 24, 48, and 72h) and the effect of the leishmanicidal extract on fibroblast cells was determined by MTS assay. Also, the flow-cytometry technique was used for the investigation of apoptosis induction percentage.

Results: MTS assay showed that the leishmanicidal effect of infected macrophage supernatant extract was dependent on the concentration and the time of treatment. So, the best efficacy was observed in 200 μg/mL with 72 hours exposure time. Flow cytometry analysis showed that the infected macrophage supernatant extract could induce apoptosis in cultured fibroblasts.

Conclusions: We have demonstrated that reduction of survival rate and induction of apoptosis in fibroblasts displayed a similar manner to keratinocytes when exposed to infected macrophages with L. major. Our data suggest that such a phenomenon can be the underlying cause of lesions with scarring, and future, the mechanism remains to be elucidated.