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See detailQuantitative assessment of mouse mammary gland morphology using automated digital image processing and TEB detection.
Blacher, Silvia ULg; Gérard, Céline ULg; Gallez, Anne ULg et al

in Endocrinology (2016)

The assessment of rodent mammary gland morphology is largely used to study the molecular mechanisms driving breast development and to analyze the impact of various endocrine disruptors with putative ... [more ▼]

The assessment of rodent mammary gland morphology is largely used to study the molecular mechanisms driving breast development and to analyze the impact of various endocrine disruptors with putative pathological implications. In this work, we propose a methodology relying on fully automated digital image analysis methods including image processing and quantification of the whole ductal tree and of the terminal end buds (TEB) as well. It allows to accurately and objectively measure both growth parameters and fine morphological glandular structures. Mammary gland elongation was characterized by two parameters: the length and the epithelial area of the ductal tree. Ductal tree fine structures were characterized by: 1) branch end-point density, 2) branching density and 3) branch length distribution. The proposed methodology was compared to quantification methods classically used in the literature. This procedure can be transposed to several software and thus largely used by scientists studying rodent mammary gland morphology. [less ▲]

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See detailPostretrieval overconfidence and anosognosia in patients with Alzheimer’s disease (AD)
Genon, Sarah ULg; Mélon, Marlène; Salmon, Eric et al

Conference (2016)

General self awareness (anosognosia) and metacognitive monitoring in memory tasks are both impaired in AD, but how they relate to each other is still an open question. We examined awareness with the ... [more ▼]

General self awareness (anosognosia) and metacognitive monitoring in memory tasks are both impaired in AD, but how they relate to each other is still an open question. We examined awareness with the Anosognosia Questionnaire Dementia (AQD) and monitoring within a memory task, during retrieval with feeling-of-knowing (FOK) and post-retrieval, with judgment-of-confidence (JOC). FOKs/JOCs were performed for names of people either previously linked to self or other. AD showed both impaired FOK and JOC. They also showed lower self metamemory effect in their JOCs and lower awareness of their behavioral functioning in the AQD, which was specifically related to overconfidence in their JOCs for self-related items. Thus, anosognosia and altered postretrieval monitoring for self-related information may be related in AD. [less ▲]

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See detailAdding mucins to an in vitro batch fermentation model of the large intestine induces changes in microbial population isolated from porcine feces depending on the substrate
Tran, Thi Hanh Tham ULg; Boudry, Christelle ULg; Everaert, Nadia ULg et al

in FEMS Microbiology Ecology (2016), 92(2), 13

Adding mucus to in vitro fermentation models of the large intestine showed that some genera, namely lactobacilli, are dependent on host-microbiota interactions and that they rely on mucosa layers to ... [more ▼]

Adding mucus to in vitro fermentation models of the large intestine showed that some genera, namely lactobacilli, are dependent on host-microbiota interactions and that they rely on mucosa layers to increase their activity. This study investigates whether this dependence on mucus is substrate-dependent and to which extend other genera are impacted by the presence of mucus. Inulin and cellulose were fermented in vitro by a fecal inoculum from pig in the presence or not of mucin-beads in order to compare fermentation patterns and bacterial communities. Mucins increased final gas production with inulin and shifted short-chain fatty acids molar ratios (P<0.001). QPCR analyses revealed that Lactobacillus spp. and Bifidobacterium spp. decreased with mucins, but Bacteroides spp. increased when inulin was fermented. A more in-depth community analysis indicated that the mucins increased Proteobacteria (0.55 vs. 0.25 %, P=0.013), Verrucomicrobia (5.25 vs. 0.03 %, P=0.032), Ruminococcaceae, Bacteroidaceae, and Akkermansia spp.. Proteobacteria (5.67 vs. 0.55 %, P<0.001) and Lachnospiraceae (33 vs. 10.4 %) were promoted in the mucuscompared to the broth, while Ruminococcaceae decreased. The introduction of mucins affected many microbial genera and fermentation patterns, but from PCA results, the impact of mucus was independent from the fermentation substrate. [less ▲]

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See detailResponse to novely and cocaine stimulant effects: lack of stability across environments in female Swiss mice
Nyssen, Laura ULg; Brabant, Christian ULg; Didone, Vincent ULg et al

in Psychopharmacology (2016), 233

Rationale: In humans, novelty/sensation seeking is seen as a personality trait with a positive relationship with addiction vulnerability. In animal studies, one of the standard proce-dures to model ... [more ▼]

Rationale: In humans, novelty/sensation seeking is seen as a personality trait with a positive relationship with addiction vulnerability. In animal studies, one of the standard proce-dures to model novelty seeking is the "response to novelty," i.e., the levels of locomotor activity in a new environment. In rodents, a positive correlation was demonstrated between the response to novelty and several effects of drugs, especially the locomotor stimulant effects of cocaine. Objectives: The present study was designed to test in mice whether the response to novelty is stable across environments and whether its relationship with the stimulant effects of cocaine is altered by environmental changes. Experiment 1 assessed the responses to novelty of the same mice in two different novel environments. Experiment 2 tested the correlation between response to novelty and acute stimulant effects of cocaine recorded in two distinct environments. Results: The results show a weak correlation only during the first 5 min of the session between the responses to novelty measured in two distinct environments. Experiment 2 demonstrates that novelty responses and stimulant effects of cocaine are positively correlated only when both behavioral responses are measured in the same environment. In contrast, the relationship between response to novelty and acute stimulant effects of cocaine is completely lost when the behavioral responses are recorded in two different environments. Conclusions: The present results question the usual interpretation of the correlation between the response to novelty and the stimulant effects of cocaine as reflecting a relationship between two underlying individual stable characteristics. [less ▲]

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See detailImplementation of the green payment within the scheme of the new Common Agricultural Policy (2015-2020): first results for 2015 in Wallonia (South of Belgium)
Burny, Philippe ULg; Terrones Gavira, François ULg

in Quality-Access to Success (2016), (Supplement), 10-14

At the end of 2013, a new Common Agricultural Policy was defined at the European level, including the implementation of the so-called “green payment”, which obliges farmers to respect three new conditions ... [more ▼]

At the end of 2013, a new Common Agricultural Policy was defined at the European level, including the implementation of the so-called “green payment”, which obliges farmers to respect three new conditions in order to get financial support through direct payments. The year 2015 being the first implementation year, the consequences on Walloon agriculture are examined. It appears that 50% of Walloon farmers are not obliged to practice crop diversification, while 16% are obliged to have at least two crops on their arable land and 33% are obliged to have at least three crops on their arable land. Less than 1% does not respect the new diversification rules. Concerning the obligation to have at least 5% of ecological focus area on the arable land, it appears that 54% of Walloon farmers are in conditions not to be obliged to respect the measure. When they implement the measure, the percentage of ecological focus areas in arable land reaches 6.9% as a mean and 2.4% do not reach the requested 5%. Finally, it can be said that the green payment does not represent a big constraint for Walloon farmers, though eventual economic consequences are still to be precised, while environmental benefits are strengthened. [less ▲]

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See detailLymphocytoses B monoclonales : de la revue de la littérature à la pratique de laboratoire.
KEUTGENS, Aurore ULg; Foguenne, Jacques; Gothot, André ULg et al

in Annales de biologie clinique (2016), 74(2), 168-175

Monoclonal B-cell lymphocytosis (MBL) is defined as an asymptomatic condition characterized by the presence of less than 5,000 monoclonal B-cells per microliter and the absence of clinical signs or ... [more ▼]

Monoclonal B-cell lymphocytosis (MBL) is defined as an asymptomatic condition characterized by the presence of less than 5,000 monoclonal B-cells per microliter and the absence of clinical signs or symptoms of a B-cell lymphoproliferative disorder. Most MBL cases involve B cells presenting an identical phenotype to CLL (CLL-like MBL) with a Catovsky-Matutes score of 3 to 5 and share the same chromosomal abnormalities than CLL. Depending on the absolute B cell count, one may distinguish low-count CLL-like MBL (<500 B cells/muL) which have no evidence of progression, no reduction in overall survival, no increase in infection risk and do not require any specific follow-up. Patients with clinical CLL-like MBL (>500 B cells/muL) have a 1% to 2% per year risk of progression to CLL requiring therapy, a higher risk of infectious complications and mortality implicating an annual follow-up by hematologist. MBL may also express other less common phenotypes and are named atypical MBL in case of CD5 antigen expression (Catovsky-Matutes score: 1-2) and non-CLL-like MBL for CD5 negative cases (Catovsky-Matutes score: 0-2). Their poorer prognosis implicates imaging studies, bone marrow biopsy and cytogenetic analysis in addition to physical examination in order to rule out non-hodgkinien lymphoma, and require a more frequent follow-up. This review focuses on key concepts in the classification, diagnosis, monitoring and biology of MBL in laboratory practice. [less ▲]

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See detailInfluence of methanol/sorbitol co-feeding rate on pAOX1 induction in a Pichia pastoris Mut+ strain in bioreactor with limited oxygen transfer rate.
Carly, F.; Niu, H.; Delvigne, Frank ULg et al

in Journal of industrial microbiology & biotechnology (2016), 43(4), 517-23

High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen ... [more ▼]

High Pichia pastoris biomass density could be obtained using high co-feeding rate of methanol and sorbitol in a fed-batch or continuous culture, while further higher feeding rate finally leads to oxygen limitation in bioreactor. In the literature, there is lack of report about AOX1 promoter regulation with regard to dissolved oxygen level (DO). Therefore, in this work, chemostat cultures were performed to investigate the cell growth, metabolism and regulation of the AOX1 promoter (pAOX1) regarding co-feeding rate of optimized methanol/sorbitol mixture (methanol fraction 0.60 C-mol/C-mol) using a P. pastoris Mut+/pAOX1-lacZ strain. The oxygen transfer rates (OTR) in bioreactor were kept in the range of typical values of large bioreactor, i.e., 4-8 g/(L h) if DO equals 30 % saturation or 5-10 g/(L h) if DO nears zero. For DO >0, an increase of the carbon fed led to an increase of pAOX1 induction. By contrast, when dissolved oxygen was completely depleted, methanol accumulated, causing a 30 % decrease of pAOX1 induction. However, this decrease is more likely to be lined to methanol accumulation than to low level of dissolved oxygen (<4 % DO). Methanol/sorbitol co-feeding allowed cells to adapt to oxygen transient limitations that often occur at industrial scale with reduced effect on pAOX1 induction. The optimal feeding rate tested here was 6.6 mmol C (DCW h)(-1) at an OTR of 8.28 g O2(L h)(-1) with over fivefold pAOX1 induction (probably directly associated with target protein productivity) compared with previous work. [less ▲]

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See detailA comprehensive density functional theory study of the key role of fluorination and dual hydrogen bonding in the activation of the epoxide/CO2 coupling by fluorinated alcohols
Alves, Margot ULg; Méreau, Raphaël; Grignard, Bruno ULg et al

in RSC Advances (2016), 6(43), 36327-36335

The activation mechanism of the CO2/propylene oxide coupling catalysed by a bicomponent organocatalyst combining the use of TBABr with (multi)phenolic or fluorinated hydrogen bond donors (HBDs) was ... [more ▼]

The activation mechanism of the CO2/propylene oxide coupling catalysed by a bicomponent organocatalyst combining the use of TBABr with (multi)phenolic or fluorinated hydrogen bond donors (HBDs) was investigated using the Density Functional Theory (DFT). Thus, it was shown that increasing the number of electron withdrawing trifluoromethyl substituents in HBDs strengthens their proton donor capability and allows a better stabilization by hydrogen bonding of the intermediates and transition states. In addition, the high efficiency of fluorinated monoalcohol activators is related to a dual hydrogen bonding mechanism by two fluorinated molecules that cooperatively contribute to the CO2/propylene oxide coupling. [less ▲]

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See detailQuadratization of symmetric pseudo-Boolean functions
Anthony, Martin; Boros, Endre; Crama, Yves ULg et al

in Discrete Applied Mathematics (2016), 203

A pseudo-Boolean function is a real-valued function $f(x)=f(x_1,x_2,\ldots,x_n)$ of $n$ binary variables; that is, a mapping from $\{0,1\}^n$ to ${\bbr}$. For a pseudo-Boolean function $f(x)$ on $\{0,1 ... [more ▼]

A pseudo-Boolean function is a real-valued function $f(x)=f(x_1,x_2,\ldots,x_n)$ of $n$ binary variables; that is, a mapping from $\{0,1\}^n$ to ${\bbr}$. For a pseudo-Boolean function $f(x)$ on $\{0,1\}^n$, we say that $g(x,y)$ is a quadratization of $f$ if $g(x,y)$ is a Quadratic polynomial depending on $x$ and on $m$ auxiliary binary variables $y_1,y_2,\ldots,y_m$ such that $f(x)= \min \{ g(x,y) : y \in \{0,1\}^m \} $ for all $x \in \{0,1\}^n$. By means of quadratizations, minimization of $f$ is reduced to minimization (over its extended set of variables) of the quadratic function $g(x,y)$. This is of some practical interest because minimization of quadratic functions has been thoroughly studied for the last few decades, and much progress has been made in solving such problems exactly or heuristically. A related paper initiated a systematic study of the minimum number of auxiliary $y$-variables required in a quadratization of an arbitrary function $f$ (a natural question, since the complexity of minimizing the quadratic function $g(x,y)$ depends, among other factors, on the number of binary variables). In this paper, we determine more precisely the number of auxiliary variables required by quadratizations of \emph{symmetric} pseudo-Boolean functions $f(x)$, those functions whose value depends only on the Hamming weight of the input $x$ (the number of variables equal to 1). [less ▲]

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See detailwicking through a confined micropillar array
Darbois-Texier, Baptiste ULg; Laurent, Philippe ULg; Stoukatch, Serguei ULg et al

in Microfluidics and Nanofluidics (2016), 20

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See detailAggressive tumor growth and clinical evolution in a patient with X-linked acro-gigantism syndrome.
Naves, Luciana A.; Daly, Adrian Francis ULg; Dias, Luiz Augusto et al

in Endocrine (2016)

X-linked acro-gigantism (X-LAG) syndrome is a newly described disease caused by microduplications on chromosome Xq26.3 leading to copy number gain of GPR101. We describe the clinical progress of a ... [more ▼]

X-linked acro-gigantism (X-LAG) syndrome is a newly described disease caused by microduplications on chromosome Xq26.3 leading to copy number gain of GPR101. We describe the clinical progress of a sporadic male X-LAG syndrome patient with an Xq26.3 microduplication, highlighting the aggressive natural history of pituitary tumor growth in the absence of treatment. The patient first presented elsewhere aged 5 years 8 months with a history of excessive growth for >2 years. His height was 163 cm, his weight was 36 kg, and he had markedly elevated GH and IGF-1. MRI showed a non-invasive sellar mass measuring 32.5 x 23.9 x 29.1 mm. Treatment was declined and the family was lost to follow-up. At the age of 10 years and 7 months, he presented again with headaches, seizures, and visual disturbance. His height had increased to 197 cm. MRI showed an invasive mass measuring 56.2 x 58.1 x 45.0 mm, with compression of optic chiasma, bilateral cavernous sinus invasion, and hydrocephalus. His thyrotrope, corticotrope, and gonadotrope axes were deficient. Surgery, somatostatin analogs, and cabergoline did not control vertical growth and pegvisomant was added, although vertical growth continues (currently 207 cm at 11 years 7 months of age). X-LAG syndrome is a new genomic disorder in which early-onset pituitary tumorigenesis can lead to marked overgrowth and gigantism. This case illustrates the aggressive nature of tumor evolution and the challenging clinical management in X-LAG syndrome. [less ▲]

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See detailCorrelation between ethanol behavioral sensitization and midbrain dopamine neuron reactivity to ethanol
Didone, Vincent ULg; Masson, Sébastien; Quoilin, Caroline et al

in Addiction Biology (2016), 21(2), 387-396

Repeated ethanol injections lead to a sensitization of its stimulant effects in mice. Some recent results argue against a role for ventral tegmental area (VTA) dopamine neurons in ethanol behavioral ... [more ▼]

Repeated ethanol injections lead to a sensitization of its stimulant effects in mice. Some recent results argue against a role for ventral tegmental area (VTA) dopamine neurons in ethanol behavioral sensitization. The aim of the present study was to test whether in vivo ethanol locomotor sensitization correlates with changes in either basal- or ethanol evoked firing rates of dopamine neurons in vitro. Female Swiss mice were daily injected with 2.5 g/kg ethanol (or saline in the control group) for 7 days and their locomotor activity was recorded. At the end of the sensitization procedure, extracellular recordings were made from dopaminergic neurons in midbrain slices from these mice. Significantly higher spontaneous basal firing rates of dopamine neurons were recorded in ethanol-sensitized mice relative to control mice, but without correlations with the behavioral effects. The superfusion of sulpiride, a dopamine D2 antagonist, induced a stronger increase of dopamine neuron firing rates in ethanol-sensitized mice. This shows that the D2 feedback in dopamine neurons is preserved after chronic ethanol administration and argues against a reduced D2 feedback as an explanation for the increased dopamine neuron basal firing rates in ethanol-sensitized mice. Finally, ethanol superfusion (10–100 mM) significantly increased the firing rates of dopamine neurons and this effect was of higher magnitude in ethanol-sensitized mice. Furthermore, there were significant correlations between such a sensitization of dopamine neuron activity and ethanol behavioral sensitization. These results support the hypothesis that changes in brain dopamine neuron activity contribute to the behavioral sensitization of the stimulant effects of ethanol. [less ▲]

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See detailÉtude des potentialités des systèmes d’application contrôlée des gouttes (CDA) pour les traitements phytosanitaires en céréaliculture (synthèse bibliographique)
Ouled Taleb Salah, Sofiene ULg; De Cock, Nicolas ULg; Massinon, Mathieu ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment (2016)

Introduction. L’application contrôlée des gouttes (CDA) présente le double avantage de réduire à la fois l’étendue de la distribution des tailles des gouttes et le volume appliqué par rapport aux buses ... [more ▼]

Introduction. L’application contrôlée des gouttes (CDA) présente le double avantage de réduire à la fois l’étendue de la distribution des tailles des gouttes et le volume appliqué par rapport aux buses hydrauliques conventionnelles. Littérature. Cette revue investigue la potentialité de la CDA par rapport aux buses hydrauliques dans le cadre du désherbage précoce des adventices (2-3 feuilles). En termes de rétention, les études reliant les caractéristiques des gouttes (taille, vitesse et direction) et l’architecture, la densité et la mouillabilité du feuillage, en fonction de la formulation de bouillies, ont été abordées. Ces études montrent que des gouttes de 300 μm avec un adjuvant approprié et des jets émis 60° vers l’avant par rapport à la verticale contribuent à l’augmentation de la rétention sur les cibles problématiques à port dressé. L’effet des réductions des volumes d’application pour ces deux techniques est étudié sur base de la moyenne, du coefficient de variation et du taux de couverture des dépôts. Néanmoins, les résultats de ces études ne peuvent être généralisés du fait des différences de réglages opératoires entre les deux techniques d’application. Quant à la dérive, les atomiseurs CDA orientés horizontalement présentent un potentiel de dérive plus important que les buses hydrauliques pour lesquelles le spray est orienté vers le bas. La dérive augmente avec la vitesse du vent et diminue lorsque le diamètre médian volumétrique (DV50) augmente. Conclusions. De nouveaux réglages des atomiseurs de la CDA en termes de DV50 et de direction du jet peuvent répondre aux défis de l’agriculture de précision. Les pistes d’innovations proposées sont d’une part une amélioration de la résistance à l’usure des dents situées en bordure des disques et, d’autre part, une distribution granulométrique plus étroite. [less ▲]

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See detailDifferential effects of context on psychomotor sensitization to ethanol and cocaine
Didone, Vincent ULg; Quoilin, Caroline; Dieupart, Julie et al

in Behavioural Pharmacology (2016), 27(2 & 3), 173-181

Repeated drug injections lead to sensitization of their stimulant effects in mice, a phenomenon sometimes referred to as drug psychomotor sensitization. Previous studies showed that sensitization to ... [more ▼]

Repeated drug injections lead to sensitization of their stimulant effects in mice, a phenomenon sometimes referred to as drug psychomotor sensitization. Previous studies showed that sensitization to cocaine is context dependent as its expression is reduced in an environment that was not paired with cocaine administration. In contrast, the effects of the test context on ethanol sensitization remain unclear. In the present study, female OF1 mice were repeatedly injected with 1.5 g/kg ethanol to test for both the effects of context novelty/familiarity and association on ethanol sensitization. A first group of mice was extensively pre-exposed to the test context before ethanol sensitization and ethanol injections were paired with the test context (familiar and paired group). A second group was not pre-exposed to the test context, but ethanol injections were paired with the test context (nonfamiliar and paired group). Finally, a third group of mice was not pre-exposed to the test context and ethanol was repeatedly injected in the home cage (unpaired group). Control groups were similarly exposed to the test context, but were injected with saline. In a second experiment, cocaine was used as a positive control. The same behavioral procedure was used, except that mice were injected with 10 mg/kg cocaine instead of ethanol. The results show a differential involvement of the test context in the sensitization to ethanol and cocaine. Cocaine sensitization is strongly context dependent and is not expressed in the unpaired group. In contrast, the expression of ethanol sensitization is independent of the context in which it was administered, but is strongly affected by the relative novelty/familiarity of the environment. Extensive pre-exposure to the test context prevented the expression of ethanol sensitization. One possible explanation is that expression of ethanol sensitization requires an arousing environment. [less ▲]

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See detailEvaluation of a New Method for the Treatment of Invasive, Diffuse, and Unexcisable Lymphangiomas of the Oral Cavity with Defocus CO2 Laser Beam: A 20-Year Follow-Up
Namour, Samir ULg; VAN HEUSDEN, Alain ULg; Namour, Amaury et al

in Photomedicine and Laser Surgery (2016), 34(2), 82-87

Abstract Objective: The aim of our study is to evaluate the efficiency of a new therapeutic method using CO2 laser to avoid mutilation or total excision for the treatment of invasive, large and ... [more ▼]

Abstract Objective: The aim of our study is to evaluate the efficiency of a new therapeutic method using CO2 laser to avoid mutilation or total excision for the treatment of invasive, large and unexcisable oral lymphangiomas. Background data: Cystic lymphatic malformations, or lymphangiomas, are mature lymphatic malformations, consisting of abnormal lymphatic vessels. Surgical excision is considered by most surgeons to be the treatment of choice for lymphangioma. Laser beam has been used to treat superficial or small lymphatic malformations by excision or by photocoagulation, and to excise or photocoagulate small lymphangiomas. Patients and methods: Seventeen patients with diffuse and unexcisable lymphangiomas were treated using a CO2 laser with specific settings: beam was 2W in noncontact and defocus mode, power density was 0.63W/cm2 for irradiation time in the range of 3– 5min, and the estimated energy density range was 114.65–191.02 J/cm2. The beam diameter at the tissular impact point was –2 cm. The laser beam was defocused to provoke a deep heat generation that would dry up the lymphatic tissues and induce deep tissue necrosis that heals by fibrous tissue process. Results: The results were satisfactory and stable, with localized recurrence in three cases. The recurrent areas were re-treated using the same technique successfully and with no further recurrence. Conclusions: The use of CO2 laser under the suggested irradiation conditions can be considered a useful technique for the treatment of invasive lymphangiomas. [less ▲]

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See detailBovine Herpesvirus 4 Modulates Its beta-1,6-N-Acetylglucosaminyltransferase Activity through Alternative Splicing.
Lété, Céline ULg; Markine-Goriaynoff, Nicolas; Machiels, Bénédicte ULg et al

in Journal of virology (2016), 90(4), 2039-51

Carbohydrates play major roles in host-virus interactions. It is therefore not surprising that, during coevolution with their hosts, viruses have developed sophisticated mechanisms to hijack for their ... [more ▼]

Carbohydrates play major roles in host-virus interactions. It is therefore not surprising that, during coevolution with their hosts, viruses have developed sophisticated mechanisms to hijack for their profit different pathways of glycan synthesis. Thus, the Bo17 gene of Bovine herpesvirus 4 (BoHV-4) encodes a homologue of the cellular core 2 protein beta-1,6-N-acetylglucosaminyltransferase-mucin type (C2GnT-M), which is a key player for the synthesis of complex O-glycans. Surprisingly, we show in this study that, as opposed to what is observed for the cellular enzyme, two different mRNAs are encoded by the Bo17 gene of all available BoHV-4 strains. While the first one corresponds to the entire coding sequence of the Bo17 gene, the second results from the splicing of a 138-bp intron encoding critical residues of the enzyme. Antibodies generated against the Bo17 C terminus showed that the two forms of Bo17 are expressed in BoHV-4 infected cells, but enzymatic assays revealed that the spliced form is not active. In order to reveal the function of these two forms, we then generated recombinant strains expressing only the long or the short form of Bo17. Although we did not highlight replication differences between these strains, glycomic analyses and lectin neutralization assays confirmed that the splicing of the Bo17 gene gives the potential to BoHV-4 to fine-tune the global level of core 2 branching activity in the infected cell. Altogether, these results suggest the existence of new mechanisms to regulate the activity of glycosyltransferases from the Golgi apparatus. IMPORTANCE: Viruses are masters of adaptation that hijack cellular pathways to allow their growth. Glycans play a central role in many biological processes, and several studies have highlighted mechanisms by which viruses can affect glycosylation. Glycan synthesis is a nontemplate process regulated by the availability of key glycosyltransferases. Interestingly, bovine herpesvirus 4 encodes one such enzyme which is a key enzyme for the synthesis of complex O-glycans. In this study, we show that, in contrast to cellular homologues, this virus has evolved to alternatively express two proteins from this gene. While the first one is enzymatically active, the second results from the alternative splicing of the region encoding the catalytic site of the enzyme. We postulate that this regulatory mechanism could allow the virus to modulate the synthesis of some particular glycans for function at the location and/or the moment of infection. [less ▲]

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See detailStructural Proteomics of Herpesviruses.
Leroy, Baptiste; Gillet, Laurent ULg; Vanderplasschen, Alain ULg et al

in Viruses (2016), 8(2),

Herpesviruses are highly prevalent viruses associated with numerous pathologies both in animal and human populations. Until now, most of the strategies used to prevent or to cure these infections have ... [more ▼]

Herpesviruses are highly prevalent viruses associated with numerous pathologies both in animal and human populations. Until now, most of the strategies used to prevent or to cure these infections have been unsuccessful because these viruses have developed numerous immune evasion mechanisms. Therefore, a better understanding of their complex lifecycle is needed. In particular, while the genome of numerous herpesviruses has been sequenced, the exact composition of virions remains unknown for most of them. Mass spectrometry has recently emerged as a central method and has permitted fundamental discoveries in virology. Here, we review mass spectrometry-based approaches that have recently allowed a better understanding of the composition of the herpesvirus virion. In particular, we describe strategies commonly used for proper sample preparation and fractionation to allow protein localization inside the particle but also to avoid contamination by nonstructural proteins. A collection of other important data regarding post-translational modifications or the relative abundance of structural proteins is also described. This review also discusses the poorly studied importance of host proteins in herpesvirus structural proteins and the necessity to develop a quantitative workflow to better understand the dynamics of the structural proteome. In the future, we hope that this collaborative effort will assist in the development of new strategies to fight these infections. [less ▲]

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