Impact of patient-reported nasal symptoms on quality of life after endoscopic pituitary surgery: a prospective cohort study

Pituitary - Endoscopic transsphenoidal surgery causes nasal morbidity and negatively affects health-related quality of life (HRQoL). Knowledge on actionable symptoms that could improve...     

Tolerogenic dendritic cells impede priming of naïve CD8+ T cells and deplete memory CD8+ T cells

Type 1 diabetes is a T‐cell‐mediated autoimmune disease in which autoreactive CD8⁺ T cells destroy the insulin‐producing pancreatic beta cells. Vitamin D3 and dexamethasone‐modulated dendritic cells (Combi‐DCs) loaded with islet antigens inducing islet‐specific regulatory CD4⁺ T cells may offer a tissue‐specific intervention therapy. The effect of Combi‐DCs on CD8⁺ T cells, however, remains unknown. To investigate the interaction of CD8⁺ T cells with Combi‐DCs presenting epitopes on HLA class I, naive, and memory CD8⁺ T cells were co‐cultured with DCs and proliferation and function of peptide‐specific T cells were analyzed. Antigen‐loaded Combi‐DCs were unable to prime naïve CD8⁺ T cells to proliferate, although a proportion of T cells converted to a memory phenotype. Moreover, expansion of CD8⁺ T cells that had been primed by mature monocyte‐derived DCs (moDCs) was curtailed by Combi‐DCs in co‐cultures. Combi‐DCs expanded memory T cells once, but CD8⁺ T‐cell numbers collapsed by subsequent re‐stimulation with Combi‐DCs. Our data point that (re)activation of CD8⁺ T cells by antigen‐pulsed Combi‐DCs does not promote, but rather deteriorates, CD8⁺ T‐cell immunity. Yet, Combi‐DCs pulsed with CD8⁺ T‐cell epitopes also act as targets of cytotoxicity, which is undesirable for survival of Combi‐DCs infused into patients in therapeutic immune intervention strategies.     

Induction of Treg by monocyte‐derived DC modulated by vitamin D3 or dexamethasone: Differential role for PD‐L1

Specific therapy with modulated DC may restore immunological tolerance, thereby obviating the need for chronic immunosuppression in transplantation or autoimmunity. In this study we compared the tolerizing capacity of dexamethasone (Dex)‐ and 1α,25‐dihydroxyvitamin D3 (VD3)‐modulated DC. Treatment of monocytes with either VD3 or Dex resulted in DC with stable, semi‐mature phenotypes compared with standard DC, with intermediate levels of co‐stimulatory and MHC class II molecules, which remained unaltered after subsequent pro‐inflammatory stimulation. IL‐12p70 secretion was lost by VD3‐ and Dex‐DC, whereas IL‐10 secretion was unaffected. VD3‐DC distinctly produced large amounts of TNF‐α. Both VD3‐ and Dex‐DC possessed the capacity to convert CD4 T cells into IL‐10‐secreting Treg potently suppressing the proliferation of responder T cells. However, only Treg induced by VD3‐DC exhibited antigen specificity. VD3‐, but not Dex‐, DC expressed significant high levels of PD‐L1 (programmed death‐1 ligand), upon activation. Blockade of PD‐L1 during priming redirected T cells to produce IFN‐γ instead of IL‐10 and abolished acquisition of regulatory capacity. Our findings demonstrate that both VD3‐ and Dex‐DC possess durable but differential tolerogenic features, acting via different mechanisms. Both are potentially useful to specifically down‐regulate unwanted immune responses and induce immune tolerance. These modulated DC appear suitable as adjuvant in antigen‐specific clinical vaccination intervention strategies.     

Islet inflammation and CXCL10 in recent‐onset type 1 diabetes

Type 1 diabetes results from a T cell‐mediated destruction of insulin‐producing pancreatic β cells. Little is known on local factors contributing to migration of T cells to pancreatic tissue. We recently demonstrated evidence of viral infection in β cells in several recent‐onset type 1 diabetes patients. Islet inflammation was analysed in a series of new‐ or recent‐onset type 1 diabetic patients and non‐diabetic control subjects. Autoimmune T cell reactivity was studied in lymphocytes derived from pancreas‐draining lymph nodes of one recent‐onset type 1 diabetes patient in partial clinical remission. Insulitic lesions were characterized by presence of β cells, elevated levels of the chemokine CXCL10 and infiltration of lymphocytes expressing the corresponding chemokine receptor CXCR3 in all pancreatic lesions of type 1 diabetes patients, regardless of enterovirus infection of β cells. CXCR3 and CXCL10 were undetectable in pancreata of non‐diabetic control subjects. T cells isolated from draining lymph nodes of a recent‐onset patient with virally infected β cells and in clinical remission reacted with multiple islet autoantigens and displayed a mixed interferon (IFN)‐γ/interleukin (IL)‐10 cytokine pattern. Our data point to CXCL10 as an important cytokine in distressed islets that may contribute to inflammation leading to insulitis and β cell destruction, regardless of local viral infection. We demonstrate further pro‐ and anti‐inflammatory islet autoreactivity, indicating that different adaptive and innate immune responses may contribute to insulitis and β cell destruction.