upregulates costimulatory and MHC molecules and enhances BCR-mediated endocytosis in Ramos cells. Ramos cells were cultured without stimulus or treated with CpG or promastigote L. panamensis antigen (pLAg) for 48 hours and then incubated with anti-IgM-biotin at 4°C and Ova-FITC-anti-biotin at 37°C for up to 3 hours. A. Expression of CD86, CD80 and HLA-DR after 48 hours of treatment. B. Means ± SD of four experiments are shown. C. FACS analysis of the frequency of Ova-FITC positive cells after 1 hour of endocytosis. Representative plots for one experiment are shown. D. Mean fluorescence intensity (MFI) for Ova-FITC in Ramos cells after 5, 10, 15, 30, 60, 120 and 180 minutes of endocytosis. One representative experiment of two is shown. E. Frequency of cells positive for Ova-FITC after 1 hour of endocytosis. Means ± SD of four experiments are shown. *p < 0.05; **p < 0.01; ***p < 0.001.