Natural Killer T Cell Function in Lymphoma Patients

Natural killer T (NKT) cells bridge innate and adaptive immune responses and play a critical role in anti-tumor immunity. The goal of the study was to assess NKT cell and T cell function in lymphoma patients and to investigate whether specific cytokines correlate with outcomes and/or immune cell function. Patient diagnoses were confirmed by histology. NKT and T cell number and function were assessed by flow cytometry and stimulation with artificial antigen-presenting cells (aAPCs) followed by ELISA and quantitative RT-PCR (qPCR). Cytokine expression levels were compared using online databases, and protein levels in the plasma were assessed by ELISA. NKT cell activation, indicated by at least 1.5-fold IFN-γ induction over baseline following stimulation, was detected in 82% of healthy donors, compared to 44% of lymphoma patients. Lymphoma patients have significantly higher levels of circulating pro- and anti-inflammatory cytokines IL-10, IL-6, and Sema4D as compared to healthy donors. In addition, NKT cell function in the blood correlated with NKT cell function in the bone marrow in lymphoma patients. We found that aAPC-qPCR can be used to quickly assess immune cell function in cancer patients. Circulating NKT cell function positively correlated with bone marrow NKT cell function, suggesting that circulating NKT responses reflect systemic immune competence. Outcome-associated transcriptomic analyses showed that lower expression of TGF-β, IL-6, IL-10, and IFN-γ mRNA correlated with poorer clinical outcomes, whereas higher Sema4D expression was associated with worse prognosis, identifying Sema4D as a potential immunologic biomarker linked to disease progression and immune dysfunction in B cell lymphoma.