A Modified NK Cell Degranulation Assay Applicable for Routine Evaluation of NK Cell Function

Figure 2

Comparison of CD107a expression on PMA + Ca²⁺ ionophore stimulated NK cells. Degranulation assay results are shown from a normal healthy control and patients with FHL2 (mutations in PRF1 encoding perforin), FHL3 (mutations in UNC13D encoding Munc13-4), FHL4 (mutations in STX11 encoding syntaxin-11), Chediak Higashi syndrome (CHS, mutations in LYST), Griscelli syndrome type 2 (GS2, mutations in RAB27a), acquired HLH, and non-HLH patients with infections and receiving treatment for the same. The percentage of CD107a⁺ NK cells is indicated on each plot. In FHL2 patients, acquired HLH patients, non-HLH patients with infection, and healthy controls the CD107a expression on NK cells increased significantly after stimulation. However, in FHL3, FHL4, CHS, and GS2 patients it did not increase, indicating defective granule release mechanism.