FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

Abstract

BACKGROUND Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis. OBJECTIVES In this study, we propose FVB/NJ mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil. METHODS AND FINDINGS We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes’ resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites of the M2269 luciferase strain. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens. MAIN CONCLUSIONS This work characterizes for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.