The immunosuppressant drug Cyclosporin A aggravates irradiation effects in endothelial cells.

The immunosuppressant drug Cyclosporin A (CsA) has been widely used to prevent the development of Graft-versus-Host Disease (GvHD) that can occur after transplantation, including allogeneic graft after accidental high-dose irradiation in humans. Here, we show that CsA alone stimulates ICAM-1 overexpression in human pulmonary microvascular endothelial cells (HPMECs) through Toll-Like Receptor 4 (TLR4) and NF-κB activation. In HPMECs, CsA treatment significantly worsened the overexpression of ICAM-1 induced by high-dose irradiation (15 Gy). This additive effect of CsA was also observed when ICAM-1 overexpression was induced by another pathway (Ca2+ entry) in macrovascular endothelial cells. In addition, CsA triggered apoptosis as well as rearrangement of the actin cytoskeleton and adherens junctions (VE-Cadherin) in microvascular endothelial monolayers. High-dose irradiation triggered similar deleterious effects in endothelial monolayers and, again, CsA treatment strongly aggravated the effects of irradiation. Altogether, these results suggest that post-transplant CsA treatment may exacerbate the deleterious effects of irradiation on the endothelium.

DosiKit, a New Portable Immunoassay for Fast External Irradiation Biodosimetry.

DosiKit is a new field-radiation biodosimetry immunoassay for rapid triage of individuals exposed to external total-body irradiation. Here, we report on the validation of this immunoassay in human blood cell extracts 0.5 h after in vitro exposure to 137Cs gamma rays, using γ-H2AX analysis. First, calibration curves were established for five donors at doses ranging from 0 to 10 Gy and dose rates ranging from ∼0.8 to ∼3 Gy/min. The calibration curves, together with a γ-H2AX peptide scale, enabled the definition of inter-experimental correction factors. Using previously calculated correction factors, blind dose estimations were performed at 0.5 h postirradiation, and DosiKit performance was compared against concomitant dicentric chromosome assay (DCA), the current gold standard for external irradiation biodosimetry. A prototype was then assembled and field tested. We show that, despite significant inter-individual variations, DosiKit can estimate total-body irradiation doses from 0.5 to 10 Gy with a strong linear dose-dependent signal and can be used to classify potentially exposed individuals into three dose ranges: below 2 Gy, between 2 and 5 Gy and above 5 Gy. The entire protocol can be performed in 45 min, from sampling to dose estimation, with a new patient triaged every 10 min. While DCA enables precise measurement of doses below 5 Gy, it is a long and difficult method. In contrast, DosiKit is a quick test that can be performed directly in the field by operational staff with minimal training, and is relevant for early field triage and identification of individuals most likely to experience acute radiation syndrome. These findings suggest that DosiKit and DCA are complementary and should be combined for triage in a mass scale event. While the proof-of-concept reported here validates the use of DosiKit at 0.5 h postirradiation, further studies are needed to calibrate and evaluate the performance of the DosiKit assay at longer times after irradiation.

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans - joint RENEB and EURADOS inter-laboratory comparisons.

PURPOSE: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. MATERIALS AND METHODS: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation-induced thermoluminescent signals in glass screens taken from mobile phones. RESULTS: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. CONCLUSIONS: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios.

The Tumor Antigen Cyclin B1 Hosts Multiple CD4 T Cell Epitopes Differently Recognized by Pre-Existing Naive and Memory Cells in Both Healthy and Cancer Donors.

Cyclin B1 (CCNB1) is considered as a potential target for a cancer vaccine, as it is overexpressed in many malignant cells, while being transiently expressed in normal cells. To evaluate the CD4 T cell response to CCNB1, we derived T cell lines by multiple weekly rounds of stimulation with recombinant CCNB1 of T cells collected in healthy donors (long-term T cell assays). T cell lines were specific for 15 immunodominant peptides and derived preferentially from naive T cells. From 74 overlapping peptides, 20 peptides were selected for their broad specificity of binding to HLA class II molecules and included most of the immunodominant epitopes. They primed in vitro a large number of specific CD4 T cell lines in all the donors. Immunodominant epitopes were the most efficacious in long-term T cell assays, both in terms of number of specific T cell lines and number of responding donors. The 20 peptides were also submitted to short-term T cell assays using cells collected in healthy and cancer patients with the aim to evaluate the memory response. The recognized peptides differed from the immunodominant peptides and were part of the best promiscuous peptides. We also observed pre-existing CCNB1-specifc IgG Abs in both healthy and cancer donors. Long- and short-term T cell assays revealed that CCNB1 contained many CD4 T cell epitopes, which are differentially recognized by pre-existing naive and memory CD4 T cells. These observations are of value for the design of cancer vaccines.

Antibodies to periodontal pathogens are associated with coronary plaque remodeling but not with vulnerability or burden.

OBJECTIVE: Previous studies have suggested positive associations between periodontal infection and cardiovascular disease. We aimed to investigate the associations of circulating antibodies against periodontal pathogens with 1-year cardiovascular outcome, as well as the extent of coronary atherosclerosis, plaque vulnerability and lesion remodeling on intravascular ultrasound (IVUS) imaging. METHODS: Between 2008 and 2011, radiofrequency IVUS imaging of a non-culprit coronary artery was performed in 581 patients who underwent coronary angiography. Immunoglobulin G (IgG) and A (IgA) against Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Prevotella intermedia were measured in plasma. RESULTS: None of the antibody levels were associated with coronary plaque burden, radiofreqeuncy-IVUS-derived thin-cap fibroatheroma lesion morphology or 1-year incidence of major adverse cardiac events (MACE), which included all-cause mortality, acute coronary syndrome and unplanned coronary revascularization. IgA against A. actinomycetemcomitans, T. forsythia and P. intermedia were inversely associated with extent of positive lesion remodeling (OR for highest versus lowest tertile 0.55, 95%CI 0.35-0.88, p = 0.012; 0.53, 95%CI 0.32-0.87, p = 0.012; and 0.64, 95%CI 0.40-1.02, p = 0.061, respectively). In diabetic patients specifically, IgG against P. gingivalis tended to be associated with coronary plaque burden (p = 0.080), while IgA against P. gingivalis tended to be associated with incident MACE (p = 0.060). CONCLUSION: Plasma IgG and IgA against major periodontal pathogens were not associated with the extent of coronary atherosclerosis (with the exception of a trend in diabetics) nor with coronary plaque vulnerability. IgA against periodontal pathogens were inversely associated with extent of coronary remodeling. Altogether, these results do not add evidence for a substantial role of systemic exposure to periodontal pathogens in coronary artery disease.