Regulation of TNF-α by 1α,25-dihydroxyvitamin D3 in human macrophages from CAPD patients

Regulation of TNF-α by 1α,25-dihydroxyvitamin D3 in human macrophages from CAPD patients.BackgroundWe have previously reported that 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3] accumulates in the dialysis fluid of uremic patients treated by continuous ambulatory peritoneal dialysis (CAPD). It has been reported that this metabolite regulates the production of cytokines by monocytes/macrophages. Since tumor necrosis factor-α (TNF-α) initiates an inflammatory cascade during peritonitis, the aim of the present study was to investigate the effect of 1α,25(OH)2D3 on the production of TNF-α by human peritoneal macrophages (HPMs).MethodsHPMs were obtained from patients on CAPD. Cells were incubated with various concentrations of 1α,25(OH)2D3, 1α,24(S) dihydroxyvitamin D2 [1α,24(S)(OH)2D2] or 25-hydroxyvitamin D3 (25-OH-D3) for 16 hours. This was followed by lipopolysaccharide (LPS; 1 μg/mL) incubation for 2.5 to 6 hours. TNF-α protein production was determined by enzyme-linked immunosorbent assay. TNF-α mRNA was assayed by the reverse transcriptase-polymerase chain reaction procedure, using internal synthetic mRNA standards for quantitative results.ResultsIncubation of HPMs with 1α,25(OH)2D3 prior to stimulation with LPS dose dependently inhibited the expression of TNF-α on both mRNA and protein levels. Similar results were obtained with the less calcemic vitamin D2 analogue 1α,24(S)(OH)2D2. Incubation of HPMs with 25-OH-D3 also revealed a down-regulation of TNF-α expression. Since this down-regulatory effect was blocked by ketoconazole, it is likely that this effect was caused by the conversion of 25-OH-D3 into 1α,25(OH)2D3 by HPMs.Conclusions1α,25(OH)2D3 has a potent inhibitory effect on the production of TNF-α by LPS-activated HPMs. We hypothesize that 1α,25(OH)2D3 may constitute a regulatory mechanism that, by controlling the intensity of the inflammatory response of the peritoneum, will moderate tissue damage during peritonitis

The role of cell-free DNA measured by a fluorescent test in the management of isolated traumatic head injuries

BACKGROUND: Traumatic brain injury (TBI) is a major cause of death and disability. In this study a new method to measure cell free DNA (CFD) for the management of TBI is tested. Our hypothesis was that CFD concentrations correlate to the magnitude of brain damage, and may predict the outcome of injured patients. METHODS: Twenty eight patients with isolated head injury were enrolled. Their demographic and clinical data were recorded. CFD levels were determined in patients' sera samples by a direct fluorescence method developed in our laboratory. RESULTS: Mean admission CFD values were lower in patients with mild TBI compared to severe injury (760 ± 340 ng/ml vs. 1600 ± 2100 ng/ml, p = 0.03), and in patients with complete recovery upon discharge compared to patients with disabilities (680 ± 260 ng/ml vs. 2000 ± 2300 ng/ml, p = 0.003). Patients with high CFD values had a relative risk to require surgery of 1.5 (95% CI 0.83 to 2.9) a relative risk to have impaired outcome on discharge of 2.8 (95% CI 0.75 – 10), and a longer length of stay (12 ± 13 days vs. 3.4 ± 4.8 days, p = 0.02). CFD values did not correlate with CT scan based grading. CONCLUSIONS: CFD levels may be used as a marker to assess the severity of TBI and to predict the prognosis. Its use should be considered as an additional tool along with currently used methods or as a surrogate for them in limited resources environment

Enhanced immune response with foot and mouth disease virus VP1 and interleukin-1 fusion genes

The capsid of the foot and mouth disease (FMD) virus carries the epitopes that are critical for inducing the immune response. In an attempt to enhance the specific immune response, plasmid DNA was constructed to express VP1/interleukin-1α (IL-1α) and precursor capsid (P1) in combination with 2A (P1-2A)/IL-1α under the control of the human cytomegalovirus (HCMV) immediateearly promoter and intron. After DNA transfection into MA104 (monkey kidney) cells, Western blotting and an immunofluorescence assay were used to confirm the expression of VP1 or P1-2A and IL-1α. Mice were inoculated with the encoding plasmids via the intradermal route, and the IgG1 and IgG2a levels were used to determine the immune responses. These results show that although the immunized groups did not carry a high level of neutralizing antibodies, the plasmids encoding the VP1/IL-1α, and P1-2A/IL-1α fused genes were effective in inducing an enhanced immune response

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016.

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]