Fig. 1

B-1P cells are highly permissive to L. amazonensis proliferation. (A) Infection of B-1P cells and BMM for 2 h with L. amazonensis stationary-phase promastigotes (MOI = 2). The results are expressed as Leishmania per 100 infected cells and correspond to the mean ± standard deviation (SD) of three independent biological assays. No statistical significance (n.s.) was observed (Student’s t-test). See also Fig. S1 for additional data. (B) Leishmania proliferation in B-1P cells and BMM after 48 h. The results are expressed as Leishmania per infected cell and correspond to the mean ± SD of triplicates. **, p < 0.003 (Student’s t-test). (C) Representative images of the in vitro infection assay (48 h) are presented in (D) and (E). By immunofluorescence, parasites are visualized in green, PV in red (LAMP-1), and the nuclei of the cells/parasites in blue (DAPI). All the channels were merged with phase contrast. The high number of parasites contained in a PV in B-1P cells is indicated (white arrow). Scale bar, 25 μm. (D) Quantification of the total of infected cells (% of infection) is shown in (C). Data correspond to the mean ± SD of biological triplicate assays. *, p < 0.0389 (Student’s t-test). (E) B-1P cells and (F) BMM were pre-treated with latrunculin A (Lat A), washed, and incubated with L. amazonensis promastigotes for the phagocytosis assay. The IN/OUT parasite assays were determined and expressed by the percentage of Leishmania in each cell. Results correspond to the mean ± SD of three independent biological assays. ***, p < 0.0001 (two-way ANOVA). See also Fig. S2 for additional data. (G) Quantification of IL-10 and (H) TNF-α in the culture supernatant of B-1P cells and BMM 24 h after infection with L. amazonensis. Results correspond to the mean ± SD of three independent biological assays. No statistical significance (n.s., p = 0.3071); ***, p < 0.001 (Student’s t-test), respectively.