Enhanced Spontaneous Anti-Tumor Cytotoxicity of Natural Killer Cells in Cutaneous T-Cell Lymphoma Patients

Cutaneous T-cell lymphoma (CTCL) is characterized by the expansion of malignant CD4+ T cells in the skin. There are two main subtypes of CTCL, mycosis fungoides (MF) and Sézary syndrome (SS). Previous studies have demonstrated defects in cell-mediated immunity, including altered cytokine profiles and decreased neutrophil function, and patients often have recurring bacterial and viral infections. Recent studies have shown increased expression of interleukin (IL)-15 in malignant CD4+ T cells in CTCL patients (Mishra et al., Cancer Discovery, 2016). Since IL-15 can enhance NK cell differentiation and activation, we hypothesized that NK cells from CTCL patients might have phenotypic and functional alterations due to these changes in homeostatic IL-15 levels.