- [Show abstract] [Hide abstract] ABSTRACT: Hepatitis B surface antigen (HBsAg)-specific T cells were analysed in 16 healthy individuals vaccinated against hepatitis B, using optimised protocols. HBsAg-specific IFN-gamma producing CD4(+) T cells were found at a similar low frequency (0.01%) within the naive T cell subset, the central and the effector memory T cell subset. Overall, HBsAg-specific total CD4(+) T cells were detected in approximately 81% of the HBV vaccinees. The use of dendritic cells substantially increased the otherwise low proliferative responses but not the percentage of IFN-gamma producing cells. The analysis of readily detectable CMV-specific CD4(+) T cell responses was used as a positive control and confirmed the adequacy of our assays. T cell responses associated with (in-) adequate hepatitis B vaccination can now be analysed in more detail.
- [Show abstract] [Hide abstract] ABSTRACT: Patients with end-stage kidney disease, whether or not on renal replacement therapy, have an impaired immune system. This is clinically manifested by a large percentage of patients unresponsive to the standard vaccination procedure for hepatitis B virus (HBV). In this study, the immune response to HBV vaccination is related to the in vitro function of monocyte-derived dendritic cells (moDC). We demonstrate that mature moDC from nonresponders to HBV vaccination have a less mature phenotype, compared to responders and healthy volunteers, although this did not affect their allostimulatory capacity. However, proliferation of autologous T cells in the presence of tetanus toxoid and candida antigen was decreased in non-responders. Also, HLA-matched CD4+ hsp65-specific human T-cell clones showed markedly decreased proliferation in the group of non-responders. Our results indicate that impairment of moDC to stimulate antigen-specific T cells provides an explanation for the clinical immunodeficiency of patients with end-stage kidney disease.
- [Show abstract] [Hide abstract] ABSTRACT: Dendritic cells (DCs) are antigen-presenting cells that are pivotal for the initiation of the primary immune response. Patients with chronic kidney disease (CKD) with or without chronic intermittent haemodialysis (CIHD) show an impaired immune response. Dysfunction of DCs may underlie this phenomenon. In this study, several different functions of monocyte-derived DCs (moDC) of patients with CKD class IV-V (glomerular filtration rate <30 ml/min) and patients on CIHD were studied in vitro and compared with age- and sex-matched healthy volunteers. We demonstrate that, independent of the maturation stimulus used, mature moDC from both groups of patients did not acquire the same level of terminal differentiation as moDC from controls, as shown by analysis of cell surface markers and the relative high macropinocytosis activity of moDC. The stimulation of allogeneic T-cells by immature moDC and mature moDC did not differ between patients and controls. However, in the presence of immature moDC or antigen-loaded maturated moDC from patients, less proliferation of autologous T-cells was observed in response to recall antigens. There was no difference between moDC from controls and patients in their ability to activate naive T-cells and to differentiate them into Th1 and Th2 cells. These results show that the terminal differentiation of moDC in patients with severe CKD is impaired. This impairment is not restricted to one maturation stimulus and is independent of treatment with haemodialysis.
- [Show abstract] [Hide abstract] ABSTRACT: We hypothesized that progressive loss of renal function specifically affects certain T cell subsets. T lymphocyte subsets of patients with chronic kidney disease and healthy controls were characterized by flow cytometry using heparin-anticoagulated whole blood samples. Plasma interleukin (IL)-7 and IL-15 concentrations were determined as these cytokines are critically involved in T cell homeostasis. The results revealed that a progressive decrease in renal function is associated with activation and selective loss of naive T cells and CD4+ central memory cells and a marked increase in CD8+ memory T cells that lack CD45RO and CCR7. The profile of T cell subsets of patients with CKD 5 with or without hemodialysis treatment was similar except for a pronounced shift to Th1 cells in hemodialysis patients. IL-7 but not IL-15 plasma concentrations were lowered in patients with end-stage renal disease as compared to healthy controls.