Pre-Clinical Development of a Recombinant,Replication-Competent Adenovirus Serotype 4 Vector Vaccine Expressing HIV-1 Envelope 1086 Clade C

Background

There is a well-acknowledged need for an effective AIDS vaccine that protects against HIV-1 infection or limits in vivo viral replication. The objective of these studies is to develop a replication-competent, vaccine vector based on the adenovirus serotype 4 (Ad4) virus expressing HIV-1 envelope (Env) 1086 clade C glycoprotein. Ad4 recombinant vectors expressing Env gp160 (Ad4Env160), Env gp140 (Ad4Env140), and Env gp120 (Ad4Env120) were evaluated.

Methods

The recombinant Ad4 vectors were generated with a full deletion of the E3 region of Ad4 to accommodate the env gene sequences. The vaccine candidates were assessed in vitro following infection of A549 cells for Env-specific protein expression and for posttranslational transport to the cell surface as monitored by the binding of broadly neutralizing antibodies (bNAbs). The capacity of the Ad4Env vaccines to induce humoral immunity was evaluated in rabbits for Env gp140 and V1V2-specific binding antibodies, and HIV-1 pseudovirus neutralization. Mice immunized with the Ad4Env160 vaccine were assessed for IFNγ T cell responses specific for overlapping Env peptide sets.

Results

Robust Env protein expression was confirmed by western blot analysis and recognition of cell surface Env gp160 by multiple bNAbs. Ad4Env vaccines induced humoral immune responses in rabbits that recognized Env 1086 gp140 and V1V2 polypeptide sequences derived from 1086 clade C, A244 clade AE, and gp70 V1V2 CASE A2 clade B fusion protein. The immune sera efficiently neutralized tier 1 clade C pseudovirus MW965.26 and neutralized the homologous and heterologous tier 2 pseudoviruses to a lesser extent. Env-specific T cell responses were also induced in mice following Ad4Env160 vector immunization.

Conclusions

The Ad4Env vaccine vectors express high levels of Env glycoprotein and induce both Env-specific humoral and cellular immunity thus supporting further development of this new Ad4 HIV-1 Env vaccine platform in Phase 1 clinical trials.     

Genomewide scan and fine-mapping linkage studies in four European samples with bipolar affective disorder suggest a new susceptibility locus on chromosome 1p35-p36 and provides further evidence of loci on chromosome 4q31 and 6q24

We present the findings of a large linkage study of bipolar affective disorder (BPAD) that involved genomewide analysis of 52 families (448 genotyped individuals) of Spanish, Romany, and Bulgarian descent and further fine mapping of the 1p34-p36, 4q28-q31, and 6q15-q24 regions. An additional sample of 56 German families (280 individuals) was included for this fine-mapping step. The highest nonparametric linkage scores obtained in the fine mapping were 5.49 for 4q31 and 4.87 for 6q24 in the Romany families and 3.97 for 1p35-p36 in the Spanish sample. MOD-score (LOD scores maximized over genetic model parameters) analysis provided significant evidence of linkage to 4q31 and at least borderline significance for the 1p and 6q regions. On the basis of these results and previous positive research findings, 4q31 and 6q24 should now be considered confirmed BPAD susceptibility loci, and 1p35-p36 is proposed as a new putative locus that requires confirmation in replication studies.     

Plant functional diversity in tropical Andean páramos

ABSTRACT

Background: Tropical high mountains present extreme daily temperature variations, frequent high air evaporative demands and seasonal differences in soil water availability. Plants have adapted to these conditions through different avoidance-tolerance mechanisms. This review focuses on plant-growth forms and their adaptive strategies.

Aims: This integrated review of páramo plant traits aims at contributing to understanding the functioning of plant-growth forms and their significance on ecosystem properties under environmental climate and land-use changes.

Methods: Plant responses are presented along avoidance-tolerance gradients considering three main aspects: freezing resistance, water relations and gas exchange characteristics. Results from 45 herbaceous and 42 woody species along elevational gradients in the Venezuelan high Andes were analysed.

Results: Leaf supercooling is the common avoidance response of woody plants to night-time freezing temperatures, while herbaceous plants tolerate frost. Trees and caulescent rosettes maintain more positive leaf water potentials under water deficit conditions compared to more tolerant herbaceous species. All plant growth-forms showed strong stomatal control under dry-season conditions.

Conclusions: Páramo plant growth-forms may be separated according to an avoidance-tolerance gradient in response to water deficit and low temperature resistance. Woody growth-forms tend to avoid both freezing and water stress, while herbaceous forms tolerate frost and resist an unfavourable water status. Grasses and cushion plants are at the tolerant extreme of the gradient and coincide in that both reach the highest elevations in the páramo. Andean giant rosettes are freezing avoidant, particularly susceptible to water deficit and the most vulnerable, of all growth-forms, to changing environmental conditions.     

Proper patterning of the optic fissure requires the sequential activity of BMP7 and SHH

The optic disc develops at the interface between optic stalk and retina, and enables both the exit of visual fibres and the entrance of mesenchymal cells that will form the hyaloid artery. In spite of the importance of the optic disc for eye function, little is known about the mechanisms that control its development. Here, we show that in mouse embryos, retinal fissure precursors can be recognised by the expression of netrin 1 and the overlapping distribution of both optic stalk (Pax2, Vax1) and ventral neural retina markers (Vax2, Raldh3). We also show that in the absence of Bmp7, fissure formation is not initiated. This absence is associated with a reduced cell proliferation and apoptosis in the proximoventral quadrant of the optic cup, lack of the hyaloid artery, optic nerve aplasia, and intra-retinal misrouting of RGC axons. BMP7 addition to organotypic cultures of optic vesicles from Bmp7-/- embryos rescues Pax2 expression in the ventral region, while follistatin, a BMP7 antagonist, prevents it in early, but not in late, optic vesicle cultures from wild-type embryos. The presence of Pax2-positive cells in late optic cup is instead abolished by interfering with Shh signalling. Furthermore, SHH addition re-establishes Pax2 expression in late optic cups derived from ocular retardation (or) embryos, where optic disc development is impaired owing to the near absence of SHH-producing RGC. Collectively, these data indicate that BMP7 is required for retinal fissure formation and that its activity is needed, before SHH signalling, for the generation of PAX2-positive cells at the optic disc.     

Enhanced expression of the beta II subspecies of protein kinase C in differentiating erythroleukemia cells

Polyclonal antipeptide antibodies which recognize selected isozymes (alpha, beta I, beta II, and gamma) of the protein kinase C family were used to identify specific subspecies in undifferentiated Friend erythroleukemia cells and in cells triggered to differentiate with hexamethylene bisacetamide. The beta II isozyme of protein kinase C was the primary isozyme expressed and its abundance was significantly increased (P less than 0.05) in differentiated cells. Differences in immunostaining between control and experimental groups were objectively quantitated by determining percentage transmission of light through cells based on color threshold rather than gray intensity levels. Staining was localized to the cytoplasm predominantly in differentiated cells, whereas nuclei stained more intensely in undifferentiated cells. These results provide immunocytochemical evidence to support the hypothesis that changes in the expression of the beta II subspecies of protein kinase C are essential to the programmed maturation of differentiating Friend erythroleukemia cells.     

Special Issue: 2019 Consortium for Trans-Pyrenean Investigations on Obesity and Diabetes

Journal of Physiology and Biochemistry - This Special Issue of the Journal of Physiology and Biochemistry contains 6 contributions that exemplify the advances obtained by the mini-network entitled...     

Proposed guidelines to evaluate scientific validity and evidence for genotype-based dietary advice

Nutrigenetic research examines the effects of inter-individual differences in genotype on responses to nutrients and other food components, in the context of health and of nutrient requirements. A practical application of nutrigenetics is the use of personal genetic information to guide recommendations for dietary choices that are more efficacious at the individual or genetic subgroup level relative to generic dietary advice. Nutrigenetics is unregulated, with no defined standards, beyond some commercially adopted codes of practice. Only a few official nutrition-related professional bodies have embraced the subject, and, consequently, there is a lack of educational resources or guidance for implementation of the outcomes of nutrigenetic research. To avoid misuse and to protect the public, personalised nutrigenetic advice and information should be based on clear evidence of validity grounded in a careful and defensible interpretation of outcomes from nutrigenetic research studies. Evidence requirements are clearly stated and assessed within the context of state-of-the-art ‘evidence-based nutrition’. We have developed and present here a draft framework that can be used to assess the strength of the evidence for scientific validity of nutrigenetic knowledge and whether ‘actionable’. In addition, we propose that this framework be used as the basis for developing transparent and scientifically sound advice to the public based on nutrigenetic tests. We feel that although this area is still in its infancy, minimal guidelines are required. Though these guidelines are based on semi-quantitative data, they should stimulate debate on their utility. This framework will be revised biennially, as knowledge on the subject increases.     

DNA fragmentation by gamma radiation and electron beams using atomic force microscopy

Double-stranded pBS plasmid DNA was irradiated with gamma rays at doses ranging from 1 to 12 kGy and electron beams from 1 to 10 kGy. Fragment-size distributions were determined by direct visualization, using atomic force microscopy with nanometer-resolution operating in non-tapping mode, combined with an improved methodology. The fragment distributions from irradiation with gamma rays revealed discrete-like patterns at all doses, suggesting that these patterns are modulated by the base pair composition of the plasmid. Irradiation with electron beams, at very high dose rates, generated continuous distributions of highly shattered DNA fragments, similar to results at much lower dose rates found in the literature. Altogether, these results indicate that AFM could supplement traditional methods for high-resolution measurements of radiation damage to DNA, while providing new and relevant information.