Fig. 2.

CD56^dim NK cells are the cells that predominantly degranulate upon co-culture with K562 and PBMC. PBMCs from patient 1 were co-cultured with or without K562 cells in the presence of either anti-CD107a mAb or isotype mAb for 6 h. After one hour of incubation, GolgiSTOP was added to minimize endocytosis. Surface antigen staining was performed using anti-CD56 and anti-CD3 mAbs. a One representative CD107a assay (patient 1 post vitamin E treatment) out of four experiments is shown. Cells were gated for either CD3 or CD56 expression (first panel). The binding of anti-CD107a-mAb to CD56^bright CD3⁻ (NK^bright), CD56^dim CD3⁻ (NK^dim), CD56⁺ CD3⁺, and CD3⁺ CD56⁻ (T cells) was quantified without (second panel) or with (third panel) K562. Panel four shows background staining of isotype control when PBMC is co-cultured with K562. B, Bar graph showing % CD107a binding after isotype subtraction of patient 1 post vitamin E treatment for the different cell subsets with or without co-culture of K562. NA not applicable due to few cells