Viruses

We proposed a new HIV-1 therapeutic vaccine based on conserved cytotoxic T lymphocyte (CTL) epitopes of archived HIV-1 DNA according to their affinity to the dominant HLA-A and -B alleles of the population investigated. Our proposal (Hla Fitted VAC, HFVAC) was composed of 15 peptides originating from the RT, gag and nef parts of proviral DNA. Our aim was to investigate baseline immune reactivity to the vaccine in HIV-1 chronically infected patients at success of antiretroviral therapy (ART) who would be eligible for a therapeutic vaccine. Forty-one patients were tested. Most of them had been infected with HIV-1 subtype B and all had been receiving successful ART for 2 to 20 years. The predominant HLA-A and -B alleles were those of a Caucasian population. ELISPOT was carried out using the HFVAC peptides. In 22 patients, the PD-1 marker was investigated on CD4+ and CD8+ T cells by flow cytometry in order to evaluate global T cell exhaustion. ELISPOT positivity was 65% overall and 69% in patients exhibiting at least one HLA allele fitting with HFVAC. The percentages of CD4+ and CD8+ T cells expressing PD-1 were high (median values 23.70 and 32.60, respectively), but did not seem to be associated with an impairment of the immune response investigated in vitro. In conclusion, reactivity to HFVAC was high in this ART-treated population with dominant HLA alleles, despite potential cellular exhaustion associated with the PD-1 marker

Plos One

One of the approaches by which the scientific community is seeking to cure HIV is the use of therapeutic vaccination. Previous studies have highlighted the importance of the virus-specific CD8+ T cell cytotoxic responses for the immune control of HIV and have oriented research on vaccine constructs based on CTL epitopes from circulating HIV-1 strains. The clinical trials with therapeutic vaccines to date have had limited success likely due to (i) a discrepancy between archived CTL epitopes in the viral reservoir and those in circulating viruses before antiretroviral therapy (ART) initiation and (ii) the lack of strong affinity between the selected CTL epitopes and the HLA grooves for presentation to CD8+ cells. To overcome these limitations, we launched the Provir/Latitude 45 study to identify conserved CTL epitopes in archived HIV-1 DNA according to the HLA class I alleles of aviremic patients, most of whom are under ART. The near full-length genomes or Gag, Pol and Nef regions of proviral DNA were sequenced by Sanger and/or Next Generation Sequencing (NGS). The HLA-A and B alleles were defined by NGS or molecular analysis. The TuTuGenetics software, which moves a sliding window of 8 to 10 amino acids through the amino acid alignment, was combined with the Immune Epitope Data Base (IEDB) to automatically calculate the theoretical binding affinity of identified epitopes to the HLA alleles for each individual. We identified 15 conserved epitopes in Pol (11), Gag (3), and Nef (1) according to their potential presentation by the dominant HLA-A and B alleles and now propose to use the corresponding conserved peptides in a multi-epitopic vaccine (HLA-fitted VAC, HFVAC)

Mediterranean-climate streams and rivers: geographically separated but ecologically comparable freshwater systems

Streams and rivers in mediterranean-climate regions (med-rivers in med-regions) are ecologically unique, with flow regimes reflecting precipitation patterns. Although timing of drying and flooding is predictable, seasonal and annual intensity of these events is not. Sequential flooding and drying, coupled with anthropogenic influences make these med-rivers among the most stressed riverine habitat worldwide. Med-rivers are hotspots for biodiversity in all med-regions. Species in med-rivers require different, often opposing adaptive mechanisms to survive drought and flood conditions or recover from them. Thus, metacommunities undergo seasonal differences, reflecting cycles of river fragmentation and connectivity, which also affect ecosystem functioning. River conservation and management is challenging, and trade-offs between environmental and human uses are complex, especially under future climate change scenarios. This overview of a Special Issue on med-rivers synthesizes information presented in 21 articles covering the five med-regions worldwide: Mediterranean Basin, coastal California, central Chile, Cape region of South Africa, and southwest and southern Australia. Research programs to increase basic knowledge in less-developed med-regions should be prioritized to achieve increased abilities to better manage med-rivers

Purification and characterization of 3β-hydroxysteroid-dehydrogenase/isomerase from bovine adrenal cortex

International audienceThe formation of 4-ene-3-ketosteroids from 3 beta-hydroxy-5-ene precursors is an obligatory step in the biosynthesis of hormonal steroids such as glucocorticoids, mineralocorticoids, estrogens and androgens. In the adrenal cortex, pregnenolone, 17 alpha-hydroxy-pregnenolone and dehydroisoandrosterone are converted to progesterone, 17 alpha-hydroxy-progesterone and androstenedione, respectively, by the enzymatic system 3 beta-hydroxy-5-ene steroid dehydrogenase and 3-keto-5-ene steroid isomerase (3 beta-HSD/I). The present work reports a two step purification procedure which yields an homogenous preparation of 3 beta-HSD/I from bovine adrenal cortex. It uses solubilization of the microsomal proteins followed by two chromatographic steps, i.e. DEAE-cellulose and heparine-sepharose columns. The enzyme was obtained as an homogeneous protein exhibiting an apparent molecular size of 45 kDa upon SDS-gel electrophoresis and of 81 kDa upon gel filtration. The purified enzyme exhibits both the 5-ene-3 beta-ol steroid dehydrogenase and isomerase activities in contrast to previous work using a more complex procedure which yielded a final preparation having lost its isomerase activity [Hiwatashi et al., Biochem. J. 98 (1985) 1519-1525]. N-terminal aminoacid (29 residues) sequence of the purified protein was determined and was found identical to that predicted from the nucleic acid sequence of the recently identified enzyme cDNA [Zhas et al. FEBS Lett. 259 (1989) 153-157]

Characterization of the novel HLA-B*14:01:13 allele by sequencing-based typing

HLA-B*14:01:13 differs from HLA-B*14:01:01:01 by one nucleotide substitution in codon 79 in exon 2

Effect of a single, oral, high-dose vitamin D supplementation on endothelial function in patients with peripheral arterial disease: a randomised controlled pilot study

Apart from its role in bone metabolism, vitamin D may also influence cardiovascular disease. The objective of this study was: (1) to determine the effect of a single, oral, high-dose vitamin D supplementation on endothelial function and arterial stiffness in patients with peripheral arterial disease (PAD) and (2) to investigate the impact of this supplementation on coagulation and inflammation parameters