HLA Class II Defects in Burkitt Lymphoma: Bryostatin-1-Induced 17 kDa Protein Restores CD4+ T-Cell Recognition
Figure 5
Bryostatin treatment increased class II peptide binding and restored class II Ag presentation in BL cell lines. (a) The BL cell lines Nalm-6.DR4 and Ramos.DR4 were treated with 0, 20, or 40 nM bryostatin-1 for 24 h. Following treatment, cells were collected, washed, and incubated with synthetic peptide for 24 h. Cells were then washed and co-cultured with the T-cell hybridoma 17.9. Supernatant from the co-culture was assayed by ELISA to determine IL-2 levels as a measure of T-cell stimulation. Results from these assays show that bryostatin-1 treatment significantly restores Ag presentation in both Nalm-6.DR4 and Ramos.DR4 to levels comparable to B-LCL. (b) Ramos.DR4 cells were treated with 40 nM bryostatin overnight and then washed, fixed, and incubated with 0 μM, 10 μM, or 40 μM of b-HSA for 3 h at 37°C with shaking. The cells were then collected and lysed, and class II/peptide complexes were detected by ELISA. *.
