PMC5958277_01
Clinical presentation. (A) Erythematous plaque on the nose and (B) skin biopsy showing vacuolated macrophages with abundant parasites (HE, 400x).
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F1
A male 65-year-old resident of Brasilia, Federal District, Brazil, presented with an erythematous plaque on his nose one month after fishing in the state of Amazonas, Brazil (Figure 1).
Cellular viability of total peripheral blood mononuclear cells (PBMCs) after SLA stimulation. The patient's total PBMCs were stained with Annexin V and propidium iodide. Medium (M), soluble Leishmania amazonensis antigen (10 microg/mL SLA), and concanavalin A (15 microg/mL conA) after 48 h of in vitro restimulation.
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F2
The in vitro experiments showed that the cells were viable, and no differences in the cell death markers were found between the SLA-treated cells and negative controls (unstimulated) (Figure 2).
Programmed death ligand 1 (PD-L1) expression in monocytes is increased after SLA restimulation. The patient's total Peripheral blood mononuclear cells were stained with anti-PD-L1 antibody. PD-L1 expression was analyzed in a population of monocytes gated by size (FSC) and granularity (SSC). Medium (M), soluble Leishmania amazonensis antigen (10 microg/mL SLA), and concanavalin A (15 microg/mL conA) after 48 h of in vitro restimulation.
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F3
We observed an increase in the expression of the inhibitory molecule PD-L1 in the monocytes restimulated in vitro with SLA (approximately 65%), whereas the negative controls were 35% positive for PD-L1 (Figure 3).
SLA decreased IFN-gamma production by CD4+ cells and IFN-gamma/granzyme B production by CD8+ T cells. The patient's total peripheral blood mononuclear cells were stained with anti-CD4, anti-CD8, anti-IFN-gamma and anti-granzyme B antibodies. (A) Lymphocytes were gated by size (FSC) and granularity (SSC), and IFN-gamma was analyzed in a CD4+ population. (B) IFN-gamma or granzyme B expression was analyzed in a CD8+ population. Medium (M), soluble L. amazonensis antigen (10 microg/mL SLA), and concanavalin A (15 microg/mL conA) after 48 h of in vitro restimulation.
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F4
We also observed a relevant decrease in granzyme B expression in CD8+ T cells, from 31% in the negative controls to 5% after SLA restimulation (Figure 4).