IL-15 induces strong but short-lived tumor-infiltrating CD8 T cell responses through the regulation of Tim-3 in breast cancer.

IL-15 has pivotal roles in the control of CD8(+) memory T cells and has been investigated as a therapeutic option in cancer therapy. Although IL-15 and IL-2 share many functions together, including the stimulation of CD8 T cell proliferation and IFN-γ production, the different in vivo roles of IL-15 and IL-2 have been increasingly recognized. Here, we explored the different effects of IL-15 and IL-2 on tumor-infiltrating (TI) T cells from resected breast tumors. We found that neither IL-2 nor IL-15 induced intratumoral CD8 T cell proliferation by itself, but after CD3/CD28-stimulation, IL-15 induced significantly higher proliferation than IL-2 during early time points, at day 2, day 3 and day 6. However, the IL-15-induced proliferation leveled off at day 9 and day 12, whereas IL-2 induced lower but progressive proliferation at each time point. Furthermore, IL-15 caused an early and robust increase of IFN-γ in the supernatant of TI cell cultures, which diminished at later time points, while the IL-2-induced IFN-γ production remained constant over time. In addition, the IL-15-costimulated CD8 T cells presented higher frequencies of apoptotic cells. The diminishing IL-15-induced response was possibly due to regulatory and/or exhaustion mechanisms. We did not observe increased IL-10 or PD-1 upregulation, but we have found an increase of Tim-3 upregulation on IL-15-, but not IL-2-stimulated cells. Blocking Tim-3 function using anti-Tim-3 antibodies resulted in increased IL-15-induced proliferation and IFN-γ production for a prolonged period of time, whereas adding Tim-3 ligand galectin 9 led to reduced proliferation and IFN-γ production. Our results suggest that IL-15 in combination of Tim-3 blocking antibodies could potentially act as an IL-2 alternative in tumor CD8 T cell expansion in vitro, a crucial step in adoptive T cell therapy.

Cytokine gene polymorphisms in hemodialysis patients: association with comorbidity, functionality, and serum albumin.

BACKGROUND: Cytokine-orchestrated chronic inflammation plays a major role in long-term morbidity and mortality in patients with end-stage renal disease (ESRD) on hemodialysis (HD). In this cross-sectional study, we evaluated the association between specific alleles/genotypes and combinations of genotypes of interleukin (IL)-6, tumor necrosis factor-alpha (TNF-alpha), and IL-10 with indices of comorbidity, functional status, and other biological markers in a cohort of 183 ESRD patients recruited to the Hemodialysis (HEMO) Study from two Boston centers. METHODS: Genotyping was performed for single nucleotide polymorphisms in the promoter region of IL-6 (-174 G-->C), TNF-alpha (-308 G-->A), and IL-10 (-1082 G-->A). The relationship of specific genotypes to the index of coexistent disease (ICED) score (an index of comorbidity), Karnofsky Index (a measure of functional status), serum albumin, and nutritional indices (anthropometric measurements, body mass index, normalized protein catabolic ratio) were studied. Plasma IL-6 levels, as well as TNF-alpha and IL-10 production by endotoxin-stimulated peripheral blood mononuclear cells (PBMC), were also measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: Patients with the high producer genotypes for the proinflammatory cytokines IL-6 (G/G and G/C) and TNF-alpha (G/A and A/A) had significantly higher comorbidity (ICED scores of > or =2) and lower functional scores (Karnofsky Index) compared with patients with the low producer genotypes for these cytokines (C/C and G/G, respectively). In contrast, patients with the high and intermediate producer genotypes (G/G and G/A) for the anti-inflammatory cytokine IL-10 had a higher Karnofsky Index compared with those with the low producer genotype (A/A). Serum albumin levels were lower in patients with the TNF-alpha high producer genotype (G/A and A/A) compared with those with the low producer genotype (G/A and A/A). On multivariate analysis, the IL-6 high producer genotypes were associated with an odds ratio (OR) of 4.87 for higher comorbidity (ICED scores > or =2) (P= 0.02), and 4.9 for lower Karnofsky Index (lower functional status) (P= 0.04) compared with patients with the low IL-6 producer genotypes. Similarly, the TNF-alpha high producer genotype was associated with increased odds for a higher ICED score, lower Karnofsky Index, and lower serum albumin compared with patients with the low producer genotype for this cytokine. In contrast, the IL-10 high/intermediate producer genotype was associated with increased odds for a higher Karnofsky Index (P= 0.05). Cytokine genotype combinations-the TNF-alpha high producer and IL-6 high producer genotype combination, and the IL-6 high producer and IL-10 low producer genotype combination-were independently associated with a higher ICED score. These genotype combinations, as well as the TNF-alpha high producer and IL-10 low producer genotype combination, were also associated with a lower Karnofsky Index. CONCLUSION: In ESRD patients on long-term HD, single nucleotide polymorphisms in the promoter region of the proinflammatory cytokines IL-6 and TNF-alpha, and the regulatory monokine IL-10, show a strong association with indices of comorbidity and function, and biological and nutritional markers.