Meta-analysis of epigenome-wide association studies of carotid intima-media thickness

Common carotid intima-media thickness (cIMT) is an index of subclinical atherosclerosis that is associated with ischemic stroke and coronary artery disease (CAD). We undertook a cross-sectional epigenome-wide association study (EWAS) of measures of cIMT in 6400 individuals. Mendelian randomization analysis was applied to investigate the potential causal role of DNA methylation in the link between atherosclerotic cardiovascular risk factors and cIMT or clinical cardiovascular disease. The CpG site cg05575921 was associated with cIMT (beta?=??0.0264, p value?=?3.5?×?10^–8) in the discovery panel and was replicated in replication panel (beta?=??0.07, p value?=?0.005). This CpG is located at chr5:81649347 in the intron 3 of the aryl hydrocarbon receptor repressor gene (AHRR). Our results indicate that DNA methylation at cg05575921 might be in the pathway between smoking, cIMT and stroke. Moreover, in a region-based analysis, 34 differentially methylated regions (DMRs) were identified of which a DMR upstream of ALOX12 showed the strongest association with cIMT (p value?=?1.4?×?10^–13). In conclusion, our study suggests that DNA methylation may play a role in the link between cardiovascular risk factors, cIMT and clinical cardiovascular disease.

     

Single-cell fate mapping reveals widespread clonal ignorance of low-affinity T cells exposed to systemic infection

T cell ignorance is a specific form of immunological tolerance. It describes the maintenance of naivety in antigen-specific T cells in vivo despite the presence of their target antigen. It is thought to mainly play a role during the steady state, when self-antigens are presented in absence of costimulatory signals and at low density or to T cells of low affinity. In how far antigen-specific T cells can also remain clonally ignorant to foreign antigens, presented in the inflammatory context of systemic infection, remains unclear. Using single-cell in vivo fate mapping and high throughput flow cytometric enrichment, we find that high-affinity antigen-specific CD8⁺ T cells are efficiently recruited upon systemic infection. In contrast, most low-affinity antigen-specific T cells ignore the priming antigen and persist in the naïve state while remaining fully responsive to subsequent immunization with a high-affinity ligand. These data establish the widespread clonal ignorance of low-affinity T cells as a major factor shaping the composition of antigen-specific CD8⁺ T cell responses to systemic infection.     

Enolase 1 of Candida albicans binds human CD4+ T cells and modulates naïve and memory responses

To obtain a better understanding of the biology behind life-threatening fungal infections caused by Candida albicans, we recently conducted an in silico screening for fungal and host protein interaction partners. We report here that the extracellular domain of human CD4 binds to the moonlighting protein enolase 1 (Eno1) of C. albicans as predicted bioinformatically. By using different anti-CD4 monoclonal antibodies, we determined that C. albicans Eno1 (CaEno1) primarily binds to the extracellular domain 3 of CD4. Functionally, we observed that CaEno1 binding to CD4 activated lymphocyte-specific protein tyrosine kinase (LCK), which was also the case for anti-CD4 monoclonal antibodies tested in parallel. CaEno1 binding to naïve human CD4⁺ T cells skewed cytokine secretion toward a Th2 profile indicative of poor fungal control. Moreover, CaEno1 inhibited human memory CD4⁺ T-cell recall responses. Therapeutically, CD4⁺ T cells transduced with a p41/Crf1-specific T-cell receptor developed for adoptive T-cell therapy were not inhibited by CaEno1 in vitro. Together, the interaction of human CD4⁺ T cells with CaEno1 modulated host CD4⁺ T-cell responses in favor of the fungus. Thus, CaEno1 mediates not only immune evasion through its interference with complement regulators but also through the direct modulation of CD4⁺ T-cell responses.     

Synthetic Evolution of a Supramolecular Harpooning Mechanism to Immobilize Vesicles at Antifouling Interfaces

The immobilization of vesicles has been conceptualized as a method to functionalize biointerfaces. However, the preservation of their integrity post immobilization remains a considerable challenge. Interfacial interactions can cause vesicle rupture upon close surface contact and non-specific protein adsorption impairing surface functions. To date, immobilization of vesicles has relied solely on either entrapment or prior modification of vesicles, both of which require laborious preparation and limit their applications. This work develops a bioinspired strategy to pin vesicles without prior modification while preserving their intact shape. This work introduces antifouling diblock copolymers and ultrathin surface-attached hydrogels containing a brush-like interface consisting of a bottle brush copolymer of N-(2-hydroxypropyl) methacrylamide (HPMA) and N-(3-methacrylamidopropyl)-N,N-dimethyldodecan-1-aminiumiodide (C12+). The presence of positive charges generates an attractive force that pulls vesicles toward the surface. At the surface, the amphiphilic properties of the combs facilitate their insertion into the membrane, mimicking the harpooning mechanism observed in antimicrobial peptides. Importantly, the antifouling poly(HPMA) backdrop serves to safeguard the vesicles by preventing deformation and breakage. Using a combination of thermodynamic analysis, surface plasmon resonance, and confocal laser scanning microscopy, this work demonstrates the efficiency of this biomimetic system to capture vesicles while maintaining an antifouling interface necessary for bioapplications.     

HLA-DR2 frequency increase in severe aplastic anemia patients is mainly attributed to the prevalence of DR15 subtype

The association between severe aplastic anemia (AA) and DR2 antigen seems to be well established. However, since discrimination between two DR2-associated splits, namely DR15 and DR16, rarely was performed, it remains unclear whether one or both of these subvariants are responsible for AA susceptibility. In this study, we have analyzed the HLA-DR allelic distribution in a group of 37 AA patients of slavic origin from North-Western Russia. The experimental design included PCR-based amplification of DRB-specific sequences, followed by reverse dot-blot hybridization of the biotinylated PCR-product with the set of sequence-specific oligonucleotide probes. HLA-DRB alleles were identified by non-radioactive enzymatic reaction, then standard serological specificities of HLA-DR antigen were estimated according to the WHO nomenclature. Whereas DR15 subtype occurred more often in the patients (23.0% vs. 13.3%, p< 0.05), DR16 split did not show the same tendency. The results, show the overall predominance of HLA-DR2 specificity (DR15+DR16) did not reach statistical significance (24.4% vs.17.5%, p<0.2). Thus, we conclude that repeatedly reported DR2 frequency increase in AA patients is mainly attributed to the prevalence of DR15 subtype.     

Modelling the cost effectiveness of antidepressant treatment in primary care

The aim of this study was to estimate the cost effectiveness of nefazodone compared with imipramine or fluoxetine in treating women with major depressive disorder. Clinical decision analysis and a Markov state-transition model were used to estimate the lifetime health outcomes and medical costs of 3 antidepressant treatments. The model, which represents ideal primary care practice, compares treatment with nefazodone to treatment with either imipramine or fluoxetine. The economic analysis was based on the healthcare system of the Canadian province of Ontario, and considered only direct medical costs. Health outcomes were expressed as quality-adjusted life years (QALYs) and costs were in 1993 Canadian dollars ($Can; $Can1 = $US0.75, September 1995). Incremental cost-utility ratios were calculated comparing the relative lifetime discounted medical costs and QALYs associated with nefazodone with those of imipramine or fluoxetine. Data for constructing the model and estimating necessary parameters were derived from the medical literature, clinical trial data, and physician judgement. Data included information on: Ontario primary care physicians' clinical management of major depression; medical resource use and costs; probabilities of recurrence of depression; suicide rates; compliance rates; and health utilities. Estimates of utilities for depression-related hypothetical health states were obtained from patients with major depression (n = 70). Medical costs and QALYs were discounted to present value using a 5% rate. Sensitivity analyses tested the assumptions of the model by varying the discount rate, depression recurrence rates, compliance rates, and the duration of the model. The base case analysis found that nefazodone treatment costs $Can1447 less per patient than imipramine treatment (discounted lifetime medical costs were $Can50,664 vs $Can52,111) and increases the number of QALYs by 0.72 (13.90 vs 13.18). Nefazodone treatment costs $Can14 less than fluoxetine treatment (estimated discounted lifetime medical costs were $Can50,664 vs $Can50,678) and produces slightly more QALYs (13.90 vs 13.79). In the sensitivity analyses, the cost-effectiveness ratios comparing nefazodone with imipramine ranged from cost saving to $Can17,326 per QALY gained. The cost-effectiveness ratios comparing nefazodone with fluoxetine ranged from cost saving to $Can7327 per QALY gained. The model was most sensitive to assumptions about treatment compliance rates and recurrence rates. The findings suggest that nefazodone may be a cost-effective treatment for major depression compared with imipramine or fluoxetine. The basic findings and conclusions do not change even after modifying model parameters within reasonable ranges.     

Biochemotherapy of advanced metastatic renal-cell carcinoma: results of the combination of interleukin-2, alpha-interferon, 5-fluorouracil,vinblastine, and 13-cis-retinoic acid

Summary We conducted a phase I/II clinical trial evaluating the sequential outpatient combination of S.C. recombinant human interleukin-2 (rIL-2; given at 10 MIU/m² b.i.d. on days 3–5 of weeks 1 and 4 and at 5 MIU/m² on days 1, 3, and 5 of weeks 2 and 3), s.c. recombinant human alpha-interferon (rIFN-; given at 6 MIU/m² on day 1 of weeks 1 and 4 and on days 1, 3, and 5 of weeks 2 and 3 and at 9 MIU/m² on days 1, 3, and 5 of weeks 5–8), i.v. bolus 5-fluorouracil (5-FU; given at 1,000 mg/m² once weekly during weeks 5–8), and i.v. bolus vinblastine (given at 6 mg/m² once weekly during weeks 5 and 8) in conjunction with p.o. 13-cis-retinoic acid (13-C-RA; given at 35 mg/m² daily during weeks 1–8). Therapy was always given in the outpatient setting. Grade 3 constitutional symptoms (malaise, chills, fevers, anorexia) were observed in 4%–8% of treatment cycles and required a 50% reduction in the doses of rIL-2 and rIFN-. None of the patients experienced major 5-FU-related toxicities such as severe diarrhea and/or stomatitis; up to 20% of patients developed vinblastine-associated peripheral polyneuropathy, which was reversible after the cessation of therapy. 13-cis-Retinoic acid produced no significant side effect; no toxic death occurred. Among 24 patients with progressive metastatic disease, there were 4 complete remissions (lung, lymph nodes) and 6 partial remissions (lung, pleura, liver, lymph nodes, and peritoneal carcinosis), for an overall objective response rate of 42% (95% confidence interval, 22%–63%). An additional 13 patients achieved disease stabilization (54%). The median time to response was 3–4 months (range, up to 6 months); all responses are continuous. In summary, although the potential synergy of biochemotherapy plus 13-cis-retinoic acid requires further preclinical investigation, the current outpatient combination regimen (rIL-2, rIFN-a, 5-FU, vinblastine, and 13-C-RA) proved to be both safe and highly effective in patients with advanced metastatic renal-cell carcinoma. A current multiinstitutional prospectively randomized trial is comparing biochemotherapy with and without concomitant 13-C-RA against rIFN- plus vinblastine.