Berry secondary metabolites and leaf physiological parameters are independently regulated by exogenous methyl jasmonate application in Sangiovese grapevines (Vitis vinifera L.)

The role of jasmonates as elicitor of secondary metabolites is well known, and many experiments have been conducted in grapevine to evaluate their effects on berry and wine quality. Even though most of these studies used foliar jasmonates applications, little investigations have been done to assess the effects on leaves which, in turn, may indirectly affect grape metabolism potentially involving a long distance signaling or crosstalk. In this experiment we jointly investigated the specific effect of jasmonates on grape berry secondary metabolites and leaf physiological parameters to better comprehend their elicitation mechanisms in grapevine. A 10 mM methyl jasmonate (MeJA) solution was applied during the lag-phase only on the leaves or only on the clusters and compared to an untreated control. The MeJA specifically affected leaf physiological parameters and berry metabolism in the treated area. When applied only on the leaves, gas exchange parameters and leaf efficiency were reduced, stimulating the senescence mechanisms, without affecting berry metabolism. On the contrary, MeJA applied on the clusters significantly delayed berry ripening, leading to hypothesize a re-route of the berry carbon resources through the biosynthesis of volatile organic compounds which were strongly increased, especially the monoterpenes in their glycosylated form.

Postharvest UV-B exposure drives changes in primary metabolism, phenolic concentration, and volatilome profile in berries of different grape (Vitis vinifera L.) varieties

BACKGROUND

The ultraviolet-B (UV-B) radiation can alter grape metabolism during berry development, but little is known on the effect of postharvest UV-B exposure. In this study, we evaluated the effect of postharvest UV-B exposure on berry primary and secondary metabolites in four grapevine varieties (Aleatico, Moscato bianco, Sangiovese, and Vermentino) in order to evaluate the possibility to increase the grape quality and its nutraceutical properties.

RESULTS

The treatment did not significantly affect the berry primary metabolism in terms of organic acids, carbohydrates, and amino acids profile, regardless of the variety. UV-B exposure reduced the total anthocyanin content, particularly the tri-substituted and di-substituted forms in Aleatico and Sangiovese, respectively. An overall negative effect of UV-B irradiation on the flavonols profile of Aleatico, Moscato bianco, and Vermentino berries was found, whereas it enhanced the quercetin, myricetin and kaempferol concentration in Sangiovese. The free fraction of berry volatile organic compounds increased in UV-B-treated Aleatico and Moscato bianco berries, especially C13 -norisoprenoids and volatile phenols, as well as key monoterpenes, such as the linalool derivatives. However, higher concentrations of glycosylated monoterpenes and C13 -norisoprenoids were measured in Sangiovese and Vermentino berries treated with UV-B.

CONCLUSION

This study provides new insights on the effect of postharvest UV-B radiation on berry secondary metabolism, highlighting a different modulation between varieties and suggesting the potential use of this technique to increase some nutraceutical and quality characteristics of grape berry. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The beneficial effect of leaf removal during fruit set on physiological, biochemical, and qualitative indices and volatile organic compound profile of the Cypriot reference cultivar 'Xynisteri'

BACKGROUND

'Xynisteri' is the reference Cypriot white cultivar that, despite its significant societal and economic impact, is poorly characterized regarding its qualitative properties, while scarce information exists regarding its aroma profile. In the current study, the effect of leaf removal during fruit set (BBCH 71) on 6-year cordon-trained, spur-pruned grapevines was assessed and an array of physiological, biochemical, and qualitative indices were monitored during successive developmental stages (BBCH 75, BBCH 85, BBCH 87, and BBCH 89). Grapes were additionally monitored for the volatile organic compounds (VOCs) profile during the advanced on-vine developmental stages (BBCH 85-BBCH 89) with the employment of gas chromatography-mass spectrometry (GC-MS), Fourier-transform near infrared (FT-NIR) spectra and electronic nose (E-nose) techniques.

RESULTS

Grape berries from the vines subjected to leaf removal were characterized by higher solid soluble sugars (SSC), titratable acidity (TA), tartaric acid, and ammonium nitrogen contents, while this was not the case for assimilable amino nitrogen (primary amino nitrogen). A total of 75 compounds were identified and quantified, including aliphatic alcohols, benzenic compounds, phenols, vanillins, monoterpenes, and C₁₃ -norisoprenoids. Leaf removal led to enhanced amounts of glycosylated aroma compounds, mainly monoterpenes, and C₁₃ -norisoprenoids. Chemometric analysis, used through FT-NIR and E-nose, showed that the aromatic patterns detected were well associated to the grape ripening trend and differences between leaf removal-treated and control grapes were detectable during fully ripe stage.

CONCLUSION

Leaf removal at fruit set resulted in an overall induction of secondary metabolism, with special reference to glycosylated aroma compounds, namely monoterpenes and C₁₃ -norisoprenoids. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Integrated Bayesian Approaches Shed Light on the Dissemination Routes of the Eurasian Grapevine Germplasm

The domestication and spreading of grapevine as well as the gene flow history had been described in many studies. We used a high-quality 7k SNP dataset of 1,038 Eurasian grape varieties with unique profiles to assess the population genetic diversity, structure, and relatedness, and to infer the most likely migration events. Comparisons of putative scenarios of gene flow throughout Europe from Caucasus helped to fit the more reliable migration routes around the Mediterranean Basin. Approximate Bayesian computation (ABC) approach made possible to provide a response to several questions so far remaining unsolved. Firstly, the assessment of genetic diversity and population structure within a well-covered dataset of ancient Italian varieties suggested the different histories between the Northern and Southern Italian grapevines. Moreover, Italian genotypes were shown to be distinguishable from all the other Eurasian populations for the first time. The entire Eurasian panel confirmed the east-to-west gene flow, highlighting the Greek role as a "bridge" between the Western and Eastern Eurasia. Portuguese germplasm showed a greater proximity to French varieties than the Spanish ones, thus being the main route for gene flow from Iberian Peninsula to Central Europe. Our findings reconciled genetic and archaeological data for one of the most cultivated and fascinating crops in the world.

The arbuscular mycorrhizal fungus Funneliformis mosseae induces changes and increases the concentration of volatile organic compounds in Vitis vinifera cv. Sangiovese leaf tissue

Arbuscular mycorrhizal fungi (AMF) are beneficial obligate symbionts of plant roots. Volatile organic compounds (VOCs) participate in plant communication and defence. The aim of this study was to analyse the effects of the arbuscular mycorrhizal fungus Funneliformis mosseae IMA1 on VOCs in Vitis vinifera cv. Sangiovese leaf tissue. Grapevine plants inoculated with F. mosseae IMA1 were incubated for 23 weeks. VOCs were extracted from leaves and identified using headspace solid-phase microextraction (HS-SPME) coupled to GC-MS. VOCs in leaf tissue were strongly enhanced (85%) by F. mosseae IMA1. The mycorrhizal fungus IMA1 modified the levels of specific VOCs synthesised in different anabolic pathways. An increase in volatiles that have been related to plant defences under pathogen/herbivore attack or linked to water stress, such as (E)-2-hexenal, 3-hexenal, geraniol, benzaldehyde and methyl salicylate, was observed in mycorrhizal plants. In contrast, some C₁₃-norisoprenoids decreased strongly in mycorrhizal plants. The study of the effects of AMF on VOCs in grapevine plants may provide useful information to establish sustainable viticultural practices.

Responses of Vitis vinifera cv. Cabernet Sauvignon roots to the arbuscular mycorrhizal fungus Funneliformis mosseae and the plant growth-promoting rhizobacterium Ensifer meliloti include changes in volatile organic compounds

Arbuscular mycorrhizal (AM) fungi and plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms that may associate with grapevine roots, improving stress tolerance, growth, and nutrition. AM fungi and PGPR enhance the production of plant secondary metabolites, including volatile organic compounds (VOCs) that play a key role in the interaction of plants with the environment and are involved in defence mechanisms. The aim of this study was to analyse the effects of an AM fungus and a rhizobacterium on plant growth and VOCs in Vitis vinifera cv. Cabernet Sauvignon roots to gain insight into the potential role of plant-rhizosphere microorganisms in vine growth and defence. Grapevines were inoculated or not with the AM fungus Funneliformis mosseae IN101 and/or the plant growth-promoting rhizobacterium Ensifer meliloti TSA41. Both microbial strains enhanced plant growth. Fifty-eight VOCs extracted from ground roots were identified using headspace solid-phase microextraction coupled to gas chromatography/mass spectrometry. VOCs were induced by F. mosseae IN101, increasing up to 87% compared with control plants. Monoterpenes were strongly enhanced by F. mosseae IN101, increasing up to 113% compared with control plants. Interestingly, monoterpene alcohols related to plant defence, such as myrtenol, p-cymen-7-ol, and p-mentha-1.8-dien-7-ol were increased. By contrast, E. meliloti TSA41 did not significantly affect VOCs. The knowledge of the effects of AM fungi and PGPR on grapevine VOCs may contribute to an integrated and sustainable management of vineyards.

Intra-varietal variability of Romanesco variety (Vitis vinifera L.)

Most historical sources that describe the presence of Romanesco variety in vine-growing areas of Lazio Region (Italy) highlighted the variability of morphological traits within the variety. This partly justifies the presence of different synonyms, true or presumed, reported by many authors for this grape variety. With the aim of analysing this variability, eight accessions related to the variety, collected in Lazio Region and grown in the DAFNE grape germplasm collection, have been characterized over five productive seasons. The ampelographic description was carried out using 50 OIV morphological descriptors and ampelometric analyses were carried out on mature leaves by SuperAmpelo software. The DNA of the different accessions, extracted from young leaves, was analyzed using 14 microsatellite loci. Furthermore, at harvest, the grapes of each accession were sampled to assess main compositive characteristics. Results showed differences among accessions on some ampelographic descriptors of the mature leaf, of the bunch, and on phenological stages. Microsatellite profiles allowed for classification of the accessions into three distinct groups. Qualitative analysis of the berry skin showed differences among accessions in the content of the main classes of phenolic compounds.

Combining color chart, colorimetric measurement and chemical compounds for postharvest quality of white wine grapes

BACKGROUND

This paper provides data for the potential use of a color chart to establish the best quality of white wine grapes destined for postharvest processing. Grechetto, Vermentino and Muscat of Alexandria white wine grape varieties were tested by sampling berries at different dates during their quality attribute evolution. A color chart and reflectance spectrocolorimeter were used in combination with analyses of total carotenoids and chlorophylls in all three varieties and of volatile organic compounds (VOCs) in Grechetto alone.

RESULTS

Total carotenoids decreased from 0.85 to 0.76 µg g^-1 in Grechetto berries and from 0.70 to 0.46 µg g^-1 in Vermentino berries while increased from 0.70 to 0.80 µg g^-1 in Muscat berries during ripening. Total chlorophylls decreased in all varieties, and a strict correlation was found between hue angle (measured by color chart or spectrocolorimeter) and chlorophyll disappearance, with R² ranging from 0.81 to 0.95 depending on the variety. VOCs were only measured in Grechetto grapes, and a significant increase in glycosylation was found with ripening. The concentration of different classes of VOCs exhibited a clear decrease during ripening, except for terpenoids and esters which showed a peak at the beginning. The benzenoid class reached the highest concentration, which was almost 50% of the total. Cluster analysis using Ward's method enabled the best grape quality to be identified.

CONCLUSION

This experimental work highlights that a color chart is cheap and easy to use to define the right quality stage for white wine grapes. The color chart enabled the enochemical features to be matched with the VOC results for the aromatic maturity of Grechetto. © 2018 Society of Chemical Industry.

Three-dimensional computational model of a blood oxygenator reconstructed from micro-CT scans

Cardiopulmonary bypass procedures are one of the most common operations and blood oxygenators are the centre piece for the heart-lung machines. Blood oxygenators have been tested as entire devices but intricate details on the flow field inside the oxygenators remain unknown. In this study, a novel method is presented to analyse the flow field inside oxygenators based on micro Computed Tomography (μCT) scans. Two Hollow Fibre Membrane (HFM) oxygenator prototypes were scanned and three-dimensional full scale models that capture the device-specific fibre distributions are set up for computational fluid dynamics analysis. The blood flow through the oxygenator is modelled as a non-Newtonian fluid. The results were compared against the flow solution through an ideal fibre distribution and show the importance of a uniform distribution of fibres and that the oxygenators analysed are not susceptible to flow directionality as mass flow versus area remain the same. However the pressure drop across the oxygenator is dependent on flow rate and direction. By comparing residence time of blood against the time frame to fully saturate blood with oxygen we highlight the potential of this method as design optimisation tool. In conclusion, image-based reconstruction is found to be a feasible route to assess oxygenator performance through flow modelling. It offers the possibility to review a product as manufactured rather than as designed, which is a valuable insight as a precursor to the approval processes. Finally, the flow analysis presented may be extended, at computational cost, to include species transport in further studies.

Cultivar-specific transcriptome prediction and annotation in Ficus carica L

The availability of transcriptomic data sequence is a key step for functional genomics studies. Recently, a repertoire of predicted genes of a Japanese cultivar of fig (Ficus carica L.) was released. Because of the great phenotypic variability that can be found in this species, we decided to study another fig genotype, the Italian cv. Dottato, in order to perform comparative studies between the two cultivars and extend the pan genome of this species. We isolated, sequenced and assembled fig genomic DNA from young fruits of cv. Dottato. Then, putative gene sequences were predicted and annotated. Finally, a comparison was performed between cvs. Dottato and Horaishi predicted transcriptomes. Our data provide a resource (available at the Sequence Read Archive database under SRP109082) to be used for functional genomics of fig, in order to fill the gap of knowledge still existing in this species concerning plant development, defense and adaptation to the environment.

Study of the terpene profile at harvest and during berry development of Vitis vinifera L. aromatic varieties Aleatico, Brachetto, Malvasia di Candia aromatica and Moscato bianco

BACKGROUND

In this work, we evaluated the aromatic composition of berries at harvest and during the whole berry development of Aleatico, Brachetto, Malvasia di Candia aromatica and Moscato bianco grapevine varieties, which were cultivated in the same vineyard and under the same agricultural conditions.

RESULTS

Malvasia had a total concentration of aroma which was significantly higher than the other grapes that showed comparable amounts with each other. The class of monoterpenes was quantitatively predominant for all four grapes, in the free and in the most plentiful bound form. In Malvasia and Aleatico there was a high prevalence of geraniol derivatives throughout the entire berry development while in Brachetto and in Moscato there was a prevalence of linalool derivatives during the green phase and geraniol derivatives during ripening.

CONCLUSION

The study of the monoterpene profile allowed us to highlight similarities and differences among the four aromatic varieties and to present a hypothesis about their biosynthetic dynamics. This information is useful for further studies on gene functional characterisation and the regulation of these important berry pathways. © 2016 Society of Chemical Industry.

Influence of vineyard altitude on Glera grape ripening (Vitis vinifera L.): effects on aroma evolution and wine sensory profile

BACKGROUND

Environmental factors have been acknowledged to greatly influence grape and wine aromas. Among them, the effect of altitude on grape aroma compounds has scarcely been debated in literature available to date. In the present study, we investigated the influence of altitude on grape composition and aroma evolution during ripening of Vitis vinifera L. cultivar Glera grown in Conegliano-Valdobbiadene DOCG area (Italy).

RESULTS

The site at highest altitude (380 m above sea level) was warmer than the lowest site (200 m above sea level) and, even with differences in temperature in the range 1.5-2 °C, the impact of the cultivation site on grape ripening and aroma accumulation and preservation was significant. The lowest site demonstrated slower grape ripening, and grapes at harvest accumulated lower amounts of all of the main classes of aroma compounds typical of the Glera variety. Wines produced from the highest site were preferred in tasting trials for their more patent floral notes and elegance.

CONCLUSION

Altitude strongly influences grape ripening evolution and flavour accumulation in the Glera grape, and this result accounts for the different styles in the sparkling wines subsequently produced. Moreover, the present study shows that aroma compound biosynthesis, particularly that of benzenoides, starts before véraison in Glera. © 2016 Society of Chemical Industry.

Physiological parameters and protective energy dissipation mechanisms expressed in the leaves of two Vitis vinifera L. genotypes under multiple summer stresses

Photosynthetic performances and energy dissipation mechanisms were evaluated on the anisohydric cv. Sangiovese and on the isohydric cv. Montepulciano (Vitis vinifera L.) under conditions of multiple summer stresses. Potted vines of both cultivars were maintained at 90% and 40% of maximum water availability from fruit-set to veraison. One week before veraison, at predawn and midday, main gas-exchange and chlorophyll fluorescence parameters, chlorophyll content, xanthophyll pool and cycle and catalase activity were evaluated. Under water deficit and elevated irradiance and temperature, contrary to cv. Montepulciano and despite a significant leaf water potential decrease, Sangiovese's leaves kept their stomata more open and continued to assimilate CO2 while also showing higher water use efficiency. Under these environmental conditions, in comparison with the isohydric cv. Montepulciano, the protective mechanisms of energy dissipation exerted by the anisohydric cv. Sangiovese were: (i) higher stomatal conductance and thermoregulation linked to higher transpiration rate; (ii) greater ability at dissipating more efficiently the excess energy via the xanthophylls cycle activity (thermal dissipation) due to higher VAZ pool and greater increase of de-epoxidation activity.

Expression of terpene synthase genes associated with the formation of volatiles in different organs of Vitis vinifera

Plants produce a plethora of volatile organic compounds (VOCs) which are important in determining the quality and nutraceutical properties of horticultural food products, including the taste and aroma of wine. Given that some of the most prevalent grape aroma constituents are terpenoids, we investigated the possible variations in the relative expression of terpene synthase (TPS) genes that depend on the organ. We thus analysed mature leaves, young leaves, stems, young stems, roots, rachis, tendrils, peduncles, bud flowers, flowers and berries of cv Moscato bianco in terms of their VOC content and the expression of 23 TPS genes. In terms of the volatile characterization of the organs by SPME/GC-MS analysis, flower buds and open flowers appeared to be clearly distinct from all the other organs analysed in terms of their high VOC concentration. Qualitatively detected VOCs clearly separated all the vegetative organs from flowers and berries, then the roots and rachis from other vegetative organs and flowers from berries, which confirms the specialization in volatile production among different organs. Our real-time RT-PCR results revealed that the majority of TPS genes analysed exhibited detectable transcripts in all the organs investigated, while only some were found to be expressed specifically in one or just a few organs. In most cases, we found that the known products of the in vitro assay of VvTPS enzymes corresponded well to the terpenes found in the organs in which the encoding gene was expressed, as in the case of (E)-β-caryophyllene synthases, α-terpineol synthase and α-farnesene synthase. In addition, we found groups of homologous TPS genes, such as (E)-β-caryophyllene and β-ocimene synthases, expressed distinctively in the various tissues. This thus confirmed the subfunctionalization events and a specialization on the basis of the organs in which they are mostly expressed.

Potential of a multiparametric optical sensor for determining in situ the maturity components of red and white Vitis vinifera wine grapes

A nondestructive fluorescence-based technique for evaluating Vitis vinifera L. grape maturity using a portable sensor (Multiplex) is presented. It provides indices of anthocyanins and chlorophyll in Cabernet Sauvignon, Merlot, and Sangiovese red grapes and of flavonols and chlorophyll in Vermentino white grapes. The good exponential relationship between the anthocyanin index and the actual anthocyanin content determined by wet chemistry was used to estimate grape anthocyanins from in field sensor data during ripening. Marked differences were found in the kinetics and the amount of anthocyanins between cultivars and between seasons. A sensor-driven mapping of the anthocyanin content in the grapes, expressed as g·kg(-1) fresh weight, was performed on a 7-ha vineyard planted with Sangiovese. In the Vermentino, the flavonol index was favorably correlated to the actual content of berry skin flavonols determined by means of HPLC analysis of skin extracts. It was used to make a nondestructive estimate of the evolution in the flavonol concentration in grape berry samplings. The chlorophyll index was inversely correlated in a linear manner to the total soluble solids (°Brix): it could, therefore, be used as a new index of technological maturity. The fluorescence sensor (Multiplex) possesses a high potential for representing an important innovative tool for controlling grape maturity in precision viticulture.

The R2R3-MYB transcription factors MYB14 and MYB15 regulate stilbene biosynthesis in Vitis vinifera

Plant stilbenes are phytoalexins that accumulate in a small number of plant species, including grapevine (Vitis vinifera), in response to biotic and abiotic stresses and have been implicated in many beneficial effects on human health. In particular, resveratrol, the basic unit of all other complex stilbenes, has received widespread attention because of its cardio-protective, anticarcinogenic, and antioxidant properties. Although stilbene synthases (STSs), the key enzymes responsible for resveratrol biosynthesis, have been isolated and characterized from several plant species, the transcriptional regulation underlying stilbene biosynthesis is unknown. Here, we report the identification and functional characterization of two R2R3-MYB-type transcription factors (TFs) from grapevine, which regulate the stilbene biosynthetic pathway. These TFs, designated MYB14 and MYB15, strongly coexpress with STS genes, both in leaf tissues under biotic and abiotic stress and in the skin and seed of healthy developing berries during maturation. In transient gene reporter assays, MYB14 and MYB15 were demonstrated to specifically activate the promoters of STS genes, and the ectopic expression of MYB15 in grapevine hairy roots resulted in increased STS expression and in the accumulation of glycosylated stilbenes in planta. These results demonstrate the involvement of MYB14 and MYB15 in the transcriptional regulation of stilbene biosynthesis in grapevine.

Delivery of natural polyphenols by polymeric nanoparticles improves the resistance of endothelial progenitor cells to oxidative stress

PURPOSE

Bone marrow-derived endothelial progenitor cells (EPCs) circulate into peripheral blood and significantly contribute to neo-vascularisation and re-endothelialisation as part of the process of vascular repair. Several studies have reported decreased EPC number in the presence of oxidative stress. Aim of this study was to evaluate the validity of mucoadhesive polymeric nanoparticles as a delivery system of natural products able to protect EPCs from oxidative stress.

METHODS

The total polyphenol content and antioxidant capacity of red grape seed extract (GSE) either pre-veraison (p-GSE) or ripe (r-GSE) were measured. Cell viability was evaluated by WST-1 assay. Nanoparticles were prepared by ionotropic crosslinking of two structurally different thiolated quaternary ammonium-chitosan conjugates. A hyaluronic acid solution, containing p-GSE or r-GSE, was added to a stirred solution of each of the two chitosan derivatives to obtain p- or r-GSE loaded nanoparticles (NP) of two types.

RESULTS

Both GSE types demonstrated strong antioxidant capacity. p-GSE showed a higher content in total polyphenols compared to r-GSE. NP size was in the 310-340 nm range, with 24 h stability, and nearly 100% encapsulation efficiency for both GSE types. NP were internalized by cells to an extent related directly with their surface charge intensity. GSE-NP uptake significantly improved cell viability and resistance to oxidation.

CONCLUSIONS

Nanotechnology has a great potential in nutraceutical delivery. The present results suggest that NP is a highly promising polyphenol carrier system particularly useful to protect EPCs from oxidative stress, thus improving their survival.

Implementation of epidural analgesia for labor: is the standard of effective analgesia reachable in all women? An audit of two years

BACKGROUND

Social and cultural factors combined with little information may prevent the diffusion of epidural analgesia for pain relief during childbirth. The present study was launched contemporarily to the implementation of analgesia for labor in our Department in order to perform a 2 years audit on its use. The goal is to evaluate the epidural acceptance and penetration into hospital practice by women and care givers and safety and efficacy during childbirth.

PATIENTS AND METHODS

This audit cycle measured epidural analgesia performance against 4 standards: (1) Implementation of epidural analgesia for labor to all patients; (2) Acceptance and good satisfaction level reported by patients and caregivers. (3) Effectiveness of labor analgesia; (4) No maternal or fetal side effects.

RESULTS

During the audit period epidural analgesia increased from 15.5% of all labors in the first trimester of the study to 51% in the last trimester (p < 0.005). Satisfaction levels reported by patients and care givers were good. A hierarchical clustering analysis identified two clusters based on VAS (Visual Analogue Scale) time course: in 226 patients (cluster 1) VAS decreased from 8.5±1.4 before to 4.1±1.3 after epidural analgesia; in 1002 patients (cluster 2) VAS decreased from 8.12±1.7 before (NS vs cluster 1), to 0.76±0.79 after (p < 0.001 vs before and vs cluster 2 after). No other differences between clusters were observed.

CONCLUSIONS

Present audit shows that the process of implementation of labor analgesia was quick, successful and safe, notwithstanding the identification of one cluster of women with suboptimal response to epidural analgesia that need to be further studies, overall pregnant womens'adhesion to labor analgesia was satisfactory.

Reweaving the social fabric: antecedents of social support facilitation

Contemporary society leaves many individuals without a continuing support group. Continued integration into a network of supportive social relationships is demonstrably related to the prevention of breakdown in health in the widest variety of mental and physical forms. Yet the task of assuring continuity of supportive relationships has not been central to any professional discipline. The facilitation of social support is likely to become more central to community health education.To address this issue we examine seven different forms of intervention which address the problem of augmenting supportive relationships. The goal is to extract the essence of the professional role in the provision of social support and to suggest its relevance to community health education.

Red grape skin and seeds polyphenols: Evidence of their protective effects on endothelial progenitor cells and improvement of their intestinal absorption

SCOPE

To evaluate the ability of grape skin and seeds to protect endothelial progenitor cells (EPC) from oxidative stress induced by hyperglycemia (HG) compared to red wine (RW) and prepare innovative pharmaceutical systems for the oral administration of red grape extract allowing the overcoming of its poor intestinal absorption.

METHODS AND RESULTS

Human EPC were characterized by expression of cell surface markers. Cells were incubated with different concentrations of total polyphenols from grape components or RW in the presence or absence of HG. Cell viability, migration, adhesion, and reactive oxygen species (ROS) production were assayed. Intestinal permeation of polyphenols was studied in the absence or presence of a quaternary ammonium-chitosan conjugate (N⁺(60)-Ch). Grape components and RW increased EPC viability, adhesion and migration, and prevented the HG effect (P < 0.01). ROS production induced by HG was significantly reduced only by grape seed extract and RW (P < 0.01). N⁺(60)-Ch acted as an effective enhancer of polyphenol permeability across the excised rat intestine.

CONCLUSIONS

Red grape components are a source of antioxidant compounds that ameliorate EPC viability and function, while preventing endothelial dysfunction. The use of polycationic chitosan derivatives can promote the absorption of polyphenols across intestinal epithelium, thus increasing their bioavailability and potential therapeutic value in atherosclerosis.

Uptake of sodium in quince, sugar beet, and wheat protoplasts determined by the fluorescent sodium-binding dye benzofuran isophthalate

The uptake of sodium into protoplasts of quince (Cydonia oblonga Mill, clone BA29), sugar beet (Beta vulgaris L. cv. Monohill), and wheat (Triticum aestivum L. cv. Kadett) was determined by use of the acetoxy methyl ester of the fluorescent sodium-binding benzofuran isopthalate (SBFI-AM). In the presence of 1 mM CaCl2, little sodium was taken up in the cytosol of quince mesophyll cells compared to cytosols of sugar beet and wheat. Upon addition of 40 mM NaCl, approximately the same amount of sodium was taken up in leaf and root protoplasts of wheat, but no sodium was taken up in quince. However, in calcium-free medium, obtained by addition of ethylene glycol tetra acetic acid (EGTA), quince protoplasts transiently took up sodium in the cytosol when 200-400 mM NaCl was added to the protoplast medium. Moreover, after cultivation of quince in the presence of 200 mM sodium for 4 weeks, the cytosol of isolated protoplasts did not take up any sodium at all from a calcium-free medium. The results show that protoplasts from salt tolerant quince only temporarily take up sodium in the cytosol and that they have a mechanism for fast extrusion of sodium from that compartment. These mechanisms are probably important for the high salt tolerance of quince. Calcium blocks the sodium uptake into the cytosol of both quince and wheat protoplasts.

Functional antagonism between IL-2 and PGA1 or PGJ2 in the control of proliferation of human cord blood-derived mononuclear cells

Cyclopentenone prostaglandins PGA1 and PGJ2 induce growth arrest at the G1/S interphase of the cell cycle in tumour cell lines. Notably, PGE, the precursor molecule of PGA, downregulates the interleukin (IL)-2-dependent proliferation of lymphocytes. Therefore the IL-2/IL-2 receptor system and relative signal transduction is a possible target of the antiproliferative effect of PGA/PGJ. In the present study the PGA1/PGJ2-dependent growth inhibition of IL-2-stimulated primary human cord blood mononuclear cells (CBMCs) was found to be mediated by interference with the IL-2 proliferative signal. Both prostaglandins (PGs) inhibited the synthesis of total RNA and protein in IL-2 stimulated cells. PGA1 and even more PGJ2 downregulated the expression of IL-2 receptor alpha (CD25 phenotype). IL-2 partly reversed this effect. Moreover, suppression of IL-2-stimulated cells was not the result of PG-mediated activation of apoptosis. On the contrary, PGs reduced both apoptosis and the high expression of c-Jun detectable in CBMCs spontaneously. Cyclin A/Cdk2 complexes regulate G1/S transition during the cell cycle. In IL-2-stimulated cells, the levels of Cdk2 were found to be lower in PG-treated cells than those detected in controls. In conclusion, cyclopentenone PGs inhibit CBMCs spontaneous or IL-2-dependent proliferation in part by interfering with the IL-2 pathway.

Prostaglandin E2 induces apoptosis in resting immature and mature human lymphocytes: a c-Myc-dependent and Bcl-2-independent associated pathway

Prostaglandin E2 (PGE2) is a known negative regulator of T lymphocyte proliferation. Previously we have indirectly evidentiated the involvement of PGE2 in apoptosis of lymphocytes both in vitro and in vivo. We have evaluated a possible direct effect of PGE2 on apoptosis. To this end we have investigated the in vitro effects of PGE2 on cell death, and its possible correlation with c-Myc and Bcl-2 proteins. We used freshly isolated unstimulated human lymphocytes from neonatal thymus, cord blood and adult peripheral blood. PGE2 induced DNA fragmentation in both peripheral and cord blood at 10(-7) to 10(-5) M concentrations, even though this induction was delayed in peripheral blood with respect to cord blood. Apoptosis induced by PGE2 was always associated with a dose-dependent increase of cellular steady state c-Myc protein levels, whereas Bcl-2 protein levels were not substantially affected. Unstimulated thymocytes showed spontaneous DNA fragmentation that occurred earlier and at higher levels in PGE2-(10(-5) M) treated cells with respect to untreated controls. Also in these cells, PGE2 produced an early increase of c-Myc protein expression, although Bcl-2 protein levels remained unchanged. In conclusion, PGE2 induces apoptosis with different kinetics on immature and mature T cells: this induction is associated with the increase of c-Myc protein expression and seems to be independent from Bcl-2 regulation.

In vitro infection of leukemic bone marrow with HTLV-I generates immortalized cell lines expressing T or myeloid cell phenotype

Leukemic bone marrow cells ( > 90% blasts) of a patient with acute myeloblastic leukemia (AML), non-treated or pretreated in vitro with a mutagenic triazene compound, were infected with HTLV-I by coculture with irradiated virus-donor cells. Immortalized, HTLV-I+, double-positive CD4/CD8 euploid T cell lines, expressing HLA class I/II monomorphic determinants, and inappropriate myeloid and progenitor cell markers (ie CD13, CD14, CD15 and CD33 antigens) were obtained. In one out of 10 triazene-pretreated samples, HTLV-I infection resulted in the appearance of a rapidly growing triploid cell line (ie MTLC1 line) showing: (1) myeloid but not lymphoid phenotype; (2) beta and delta T cell receptor in germline configuration; (3) integrated, complete and incomplete HTLV-I provirus genome (also detected in a number of MTLC1 clones); (4) a high percentage of cells positive for non-specific cross-reacting antigen (a CEA-related molecule present in myeloid cells) under the influence of gamma-interferon; (5) absence of HLA class I/II antigen expression; (6) absence of tax gene transcription. Blast cell proliferation was marginal or absent when leukemic marrow was not subjected to retroviral infection. These results show that exposure of leukemic bone marrow to HTLV-I can be followed by immortalization of T and myeloid cells. Although no data are available to establish whether tax expression played a role in the early phase of the immortalization process of MTLC1 line, tax gene product was not required for maintaining long-term growth of MTLC1 cells.

HSP70 production and inhibition of cell proliferation in Molt-4 T-cells after cell-to-cell transmission of HTLV-I: effect of PGA1

Infection with HTLV-I is associated with leukemic transformation of mature CD4+ T lymphocytes. PGA1, a powerful inhibitor of tumour cell proliferation, can prevent the clonal expansion of HTLV-I-infected cells following acute infection of cord blood-derived mononuclear cells. Since the antiproliferative effect of PGA1 on HTLV-I transformed, chronically infected MT-2 cell line was associated with induction of HSP70, we have investigated the effect of PGA1 on cell cycle progression and HSP70 production in a leukemic T-cell line (Molt-4) shortly after exposure to HTLV-I in a cell-to-cell transmission model. Rate of cell proliferation and HSP70 expression were studied within one duplication cycle of Molt-4 cells after exposure to HTLV-I. Growth of both control and virus-exposed cultures was inhibited by treatment with PGA1 (4 micrograms/ml) and cell cycling was arrested preferentially at the G1/S interphase. Synthesis of HSP70 was induced within 3 h by PGA1 in control and virus-exposed Molt-4 cells and became undetectable from overnight onward, though the protein accumulated in the cells. The arrest of growth was observed from overnight up to 48 h so that treated cells almost missed one cycle. Interestingly, HSP70 transcript and protein persisted at remarkably high levels in Molt-4 cells exposed to HTLV-I in the absence of PGA1, showing that HSP70 expression can be directly activated during primary infection with this human retrovirus. Moreover, in these cocultures, treatment with PGA1 or heat shock was not able to increase further the elevated level of HSP70 found in untreated cocultures, suggesting that during the early period of the virus-transmission phase, HTLV-I could interfere with HSP70 induction by other inducers.

Cell-cycle progression and apoptosis in K562 and Molt-4 cells after cell-to-cell transmission of HTLV-I: modulation by interferons

Human T-cell leukemia virus type I (HTLV-I) is mainly propagated by cell division and therefore the virus-driven proliferation of infected cells can represent a predisposing condition to final development of adult T-cell leukemia (ATL) in vivo. To correlate virus expression and cell cycle progression of recipient cells after acute infection with HTLV-I, K562 multipotent erytholeukemia and Molt-4 T-lymphoma cells were used as recipient cells in a cell-to-cell virus transmission model. Cell cycle progression was studied by flow cytometry during one duplication cycle of recipient cells and transcription of HTLV-I was evaluated during the same time course. The antiproliferative and antiviral effects of recombinant interferons alpha, beta and gamma were also evaluated on cell cycle progression and HTLV-I expression. Transcription of HTLV-I in immortalised virus-donor MT-2 T-cells was found to be related to cell cycle. After coculturing recipient K562 or Molt-4 cells with lethally irradiated, non-dividing virus-donor MT-2 cells, progression into cell cycle of recipient cells was delayed. A pre-G(1) peak, corresponding to 6-11 % apoptotic cells, was identified in cocultured Molt-4/MT-2 cells and not in Molt-4 controls, and was not affected by treatment with IFNs. Notably, no such peak was identified either in control or in cocultured K562 cells. During this time course, transcription of the viral subgenomic mRNA encoding for the env-pX region was prevalently observed. Treatment with IFNalpha and especially with IFNbeta at the onset of the cultures inhibited the growth of both control and virus-exposed recipient cells. IFNgamma was less effective. A clearcut reduction of the percentage of cells entering the S phase was observed only after treatment with IFNbeta. At the same time, in IFNbeta-treated cocultures a marked inhibition of transcription of viral mRNA was observed, suggesting that, during acute infection, treatment with IFNbeta contributes to reduce the infection of recipient cells by down-regulating both the cellular proliferation rate and virus transcription in infected cells.

Effects of cyclopentenone prostaglandins on myeloid cells during early infection with HTLV-I. I. Cell differentiation determines sensitivity to prostaglandins and virus infection

Human myeloid cell lines at different stages of differentiation (K562, HL60 and U937) were used to analyze the permissivity of the myelomonocytic lineage to acute infection with human T-cell leukemia virus type-I (HTLV-I) after cell-to-cell transmission and to evaluate the effect of cyclopentenone prostaglandins (PG)A1 and PGJ2 on virus transmission, proliferation of recipient cells and cell-mediated cytotoxicity against virus-donor cells. Exposure to HTLV-I delayed the growth rate of recipient cells, especially in U937 cells. This effect was related to the phase of cell cycle when cells were exposed to HTLV-I. Treatment of control and virus-exposed cells with these PGs, both inducing growth arrest prevalently at the G1/S interphase of the cell cycle, inhibited cell proliferation in a concentration-dependent way. The antiproliferative effect of both PGs increased progressively from pluripotent K562 to promyelocytic HL60 and monoblastoid U937 cells, suggesting that differentiated cells were more susceptible to PG-mediated inhibition of growth than pluripotent cells. PG treatment influenced the permissivity of recipient cells to HTLV-I, with different effects on less differentiated myeloid cells in comparison with more differentiated monoblastoid cells. In fact, the percentage of cells positive for the p19gag protein was increased among PG-treated K562 or HL60 cells, although it was reduced in PG-treated U937 cells. To this respect, PGA1 was more effective on asynchronous and PGJ2 on synchronous U937 cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of cyclopentenone prostaglandins on myeloid cells during early infection with HTLV-I. II. Regulation of synthesis of inducible p72 heat shock protein

Differentiation of cells of myelomonocitic lineage influences both cellular permissivity to infection with human T-cell leukemia virus type I after cell-to-cell virus transmission and sensitivity to the antiproliferative effect of cyclopentenone prostaglandins (PG)A1 and PGJ2. Growth inhibition and control of infection were found to be associated with high intracellular levels of inducible p72 heat shock protein (HSP70). Pluripotent K562 cells produced higher HSP70 base-line levels than promyelocytic HL60 or monoblastoid U937 cells. Treatment with PGA1 and especially with PGJ2 enhanced the synthesis of HSP70 in all these cells. Notably, HSP70 accumulated in virus-exposed U937 cells (but not in K562 or HL60 cells). Because in lethally irradiated virus-donor cells HSP70 production was barely detectable, expression of this protein in cocultured U937 cells can be prevalently attributed to virus-recipient cells. Treatment with PGA1 and even more with PGJ2 remarkably enhanced the synthesis of HSP70 in virus-exposed U937 cells, thus resulting in persistently high levels of HSP70 protein in the cells. As shown previously, in U937 cells treatment with PGs was associated with reduced percentages of virus p19gag positive cells and enhanced specific lysis of virus-donor cells at early time points after cell-to-cell transmission. Because the HSP70 protein family is involved in the control of cell proliferation as well as in antigen processing function during the immune response to pathogens, it is possible that persistent high expression levels of HSP70 in PG-treated cells play a critical role in regulating both cell cycling and antiviral cellular responses.

Antiproliferative activity of cyclopentenone prostaglandins in early HTLV-1 infection is independent of IL-2 and is associated with HSP70 induction

Cyclopentenone prostaglandins PGA1 and PGJ2 can inhibit the growth of HTLV-1 infected cord blood-derived human mononuclear cells (CBMC), both after acute infection and in chronically infected, immortalized cells. When CBMC were exposed to HTLV-1 infection by coculturing with lethally irradiated, virus-donor allogeneic MT-2 cells, they underwent a proliferative response, that peaked within the first week and then declined. PG treatment did not inhibit the initial proliferation (day 4) of cocultured CBMC, while multiple treatments with PGA1 and more efficiently with PGJ2, suppressed the late cell proliferation (from day 8 onward). The pharmacological effects of PGA1 and PGJ2 were reversible and therefore multiple treatments were required to maintain their antiproliferative activity. Increasing concentrations (20, 40, 80 IU/ml) of recombinant IL-2 did not affect the virus-associated proliferative response of CBMC, and exogenous IL-2 did not revert the antiproliferative effect of both PGs. Arrest of proliferation in cocultured CBMC occurred concomitantly with expression of high levels of HSP70 in the cells. In fact, though HSP70 expression was induced early (day 5) after exposure to HTLV-1, its expression was further increased after multiple PG treatments and high levels were found when the antiproliferative effect of PGs became manifest. Since HSP70 protein family is involved in the control of cell cycle as well as in antigen processing and presentation during the immune response against tumor cells and pathogens, the persistent expression of this protein in PG-treated cocultures suggested that, beside inhibiting the growth of virus-infected cells, HSP70 expression might play a role in modulating the immune function of CBMC. However, unlike in most virus infection models, in which cyclopentenone PGs exert clear antiviral effects by inhibiting the synthesis and maturation of virus proteins, no antiviral activity was found in this model of infection. This strongly suggests that the main effect of these PGs against HTLV-1 infected cells consists in inhibiting proliferation in vitro without affecting viral expression.

Protective effect of interferon beta on human T cell leukaemia virus type I infection of CD4+ T cells isolated from human cord blood

The present study shows the effect of human interferon beta (IFN beta) on the susceptibility of highly purified cord blood CD4+ T cells to infection with the human T cell leukaemia virus type I (HTLV-I). Unfractionated cord blood mononuclear cells (CBMC), or a separated CD4+ T cell subpopulation (CBCD4) were exposed to HTLV-I by cocultivation with a chronically infected virus-donor cell line. The results show that presence of proviral DNA as well as virus transcription was markedly reduced by IFN beta in both populations, indicating that this cytokine protects not only unfractionated CBMC but also purified CBCD4 cells from virus infection. Moreover IFN beta treatment caused 60%-80% inhibition of virus expression in CBCD4, assayed as the presence of virus core protein p19. This study demonstrates that IFN beta is able to inhibit HTLV-I infection of CBMC through a mechanism that does not necessarily involve cell-mediated natural or antigen-dependent immunity afforded by CBMC subpopulations distinct from targets of HTLV-I infection. Therefore it is reasonable to conclude that IFN beta has a direct protective effect on CBCD4, through induction of antiviral resistance/activity in target cells.

Combined treatments with interferon (alpha,beta) plus PGA1 to control early infection with HTLV-I in primary cord blood-derived mononuclear cells

Interferon (IFN) alpha and beta can activate an antiviral and immunomodulating response in primary cord blood-derived mononuclear cells (CBMC) exposed to infection with Human T-cell Leukemia Virus type I (HTLV-I), resulting in partial inhibition of early infection in vitro. On the other hand, PGA1, a PGE1-derived cyclopentenone prostaglandin, can inhibit in vitro the proliferation of virus-infected CBMC, preventing the emergence of the potentially transformed clone. In order to achieve a complete control of HTLV-I infection in this experimental model, we evaluated whether the antiviral activity of IFNs and the antiproliferative activity of PGA1 could be preserved in a combination therapy scheme. Recipient CBMC were treated with IFN alpha or beta (1000 IU/ml) at the onset of the co-culture with lethally irradiated virus-donor MT-2 cells, followed by multiple treatments with PGA1 (4 micrograms/ml every 4 days, starting on day 0) for 6 weeks post infection (p.i.). In PGA1-treated co-cultures the percentage of virus-positive CBMC was constantly doubled during culture time as well as the amount of viral transcripts and p19 virus core protein production were increased. The antiviral effects of IFNs, resulting in about a 50% reduction of the percentage of virus-positive CBMC and consequently in a partial inhibition of virus expression (HTLV-I transcription and p19 production) until 4 weeks p.i., were suppressed by multiple PGA1 treatments. However, the antiproliferative effect of PGA1 was enforced in IFN-treated co-cultures, leading to earlier control of proliferation of virus-infected cells. Interestingly, infection of CBMC with HTLV-I was associated with persistent expression of 70 kDa heat shock protein (HSP70), for at least 4 weeks p.i. IFNs and PGA1 showed antagonistic effects on HSP70 production in infected CBMC. In fact, production of HSP70 was suppressed (or prevented) in IFN-treated co-cultures, tested 2 and 4 weeks p.i. The fact that the expression of HSP70 is apparently suppressed (or prevented) by IFN treatment is surprising, since expression of this protein family has been associated with antiviral immunity. PGA1 could totally reverse the IFN-mediated suppression of HSP70 expression in these co-cultures. It is presently unclear whether HSP70 expression is directly involved in the control of proliferation exerted by PGA1 against virus-infected CBMC or is an epiphenomenon associated with inhibition of cell growth.

Ocular involvement correlated with age in patients affected by major and intermedia beta-thalassemia treated or not with desferrioxamine

We examined 25 patients affected from Cooley's disease and five by beta-thalassemia intermedia. The mean age was 15 +/- 6.3 years. Fifteen patients, (18 years or older) three of them affected by beta-thalassemia intermedia, presented ocular abnormalities. So it was impossible to establish a correlation between laboratory data and ocular damages; their observation, with reference to untreated beta-thalassemia subjects, suggested that ocular abnormalities cannot be only attributed to desferrioxamine treatment.

Antiviral activity of individual versus combined treatments with interferon alpha, beta and gamma on early infection with HTLV-I in vitro

We have shown previously that infection of mononuclear cells derived from neonatal cord (CBMC) or adult peripheral (PBMC) blood with HTLV-1 can be controlled in vitro by treatment with interferon (IFN) alpha, beta or gamma. The activity of IFNs was mainly related to the induction of an active antiviral competence in host's immune effector cells. The antiviral activity of IFN-boosted CBMC could be ascribed both to a positive regulation of cell-mediated immunity and to inhibition of viral infection. Data described herein provide further information on the mechanisms of the antiviral activity of IFNs and compare the activity of each type of IFN with the association of alpha + beta, alpha + gamma and beta + gamma IFNs, at a concentration of 100 or 1000 IU/ml. When added at the onset of the co-culture of CBMC with lethally irradiated, virus-donor MT-2 cells, IFNs could protect host CBMC by inhibiting HTLV-1 infection in terms of reduced proviral integration and a lower percentage of virus-positive cells, until 4 weeks of culture. Infection of CBMC was inhibited at a comparable extent by either individual or combined IFN treatments. However, a clearcut inhibition of HTLV-I transcription was found only when alpha 100 + beta 1000 IU/ml and especially alpha 1000 + gamma 100 IU/ml combined treatments were tested. When the chronically infected, virus-producing MT-2 cells were treated with IFNs, a remarkable inhibition of HTLV-I transcription was found only after multiple treatments. However, MT-2 cells became resistant to the antiviral activity of IFN gamma, but not to that of IFN alpha or beta. These data provide further information on the control of HTLV-I replication mediated by IFNs at different steps of the viral life cycle, being therefore relevant to the clinical use of combined IFNs in the treatment of acute infection. Moreover, IFNs could be used to prevent the establishment of a persistent infection, which is a prerequisite for developing adult T-cell leukemia (ATL) and/or virus-associated myelopathy.

Comparative anti-viral and anti-proliferative activity of PGA1 and PGJ2 against HTLV-I-infected MT-2 cells

Prostaglandin (PG) A and J exert anti-viral and anti-proliferative effects in a number of experimental models. In particular, multiple treatments with PGAs prevent in vitro the clonal selection of HTLV-I-infected and potentially transformed cord-blood-derived mononuclear cells. Proliferation of HTLV-I-infected leukemic T cells is refractory in most cases to conventional anti-blastic therapy. We examined whether these cyclopentenone PGs might control cell proliferation and/or alter virus replication also in HTLV-I-transformed cells. We show that PGA1 and PGJ2 can exert powerful control of proliferation of the HTLV-I-immortalized, virus-producing MT-2 cell line, in a concentration-dependent fashion. Cells were preferentially arrested at the G1/S interface by treatment with PGA1 or PGJ2 without any detectable cellular toxicity. The anti-proliferative effect of PG treatment was independent of the growth phase of MT-2 cells, since both asynchronous and synchronous cells were sensitive to treatment. This effect was accompanied by an increase in the synthesis of a 70 kDa heat-shock protein (HSP70). However, synthesis of HSP70 was induced to a much greater extent by PGJ2 than by PGA1 at the same concentration. Neither PGA1 or PGJ2 inhibited the transcription of HTLV-I in MT-2 cells, but treatment with PGJ2, and not with PGA1, moderately inhibited the synthesis of viral proteins, i.e., p40 Tax and p19 core proteins. Moreover, infection of recipient K562 cells was significantly inhibited after pre-treatment of MT-2 cells with PGJ2 14 hr before or co-treatment at the onset of the co-culture with K562 cells. This effect was not obtained when MT-2 cells were repeatedly pre-treated with PGJ2 for 1 week before co-culturing. This suggests that reduced infection could be related to impairment of some step in virus-transmission phase.

[Etiopathogenesis and therapeutic trends in adult T-cell leukemia associated with HTLV-I retrovirus]

HTLV-I (Human T-cell leukemia virus type I) has been the first human retrovirus identified and then associated with a definite pathological entity, a leukemic syndrome that specifically affects mature T-lymphocytes (ATL, adult T-cell leukemia), expressing CD3+, CD4+, CD8-, CD11- phenotype. This form of leukemia/lymphoma is endemic in southwestern islands of Japan, although at present the number of HTLV-I seropositive individuals has greatly increased, with a worldwide diffusion, following the expansion wave of the AIDS-associated HIV retrovirus. In fact, double seropositivity for both HIV and HTLV is frequently found among intravenous drug users. Although ATL leukemia or lymphoma occurs with a low frequency among HTLV-I seropositive individuals, it is likely that the evolution from a latent phase of infection to acute leukemia could be favoured by depression of immunosurveillance levels in the host. Therefore, special attention is required to prevent the diffusion of this retrovirus in adults, taking into consideration that newborn babies from seropositive mothers have to be considered at high risk for development of HTLV-I associated disease, on the basis of their immature immunocompetence.

An immunopharmacological approach for prevention of retrovirus-associated disease in human pathology

Retroviruses of the HTLV and HIV subfamilies share a number of similar properties in terms of route of transmission and ultimate targeting to CD4+ T-cells, which results in leukaemic transformation in the case of HTLV and in depletion of CD4+ population and failure of T-helper function in HIV-infected individuals. Both diseases gain poor benefit from therapy at the stage of clinical diagnosis as ATL leukaemia or AIDS, respectively. Therefore the best chances to limit the worldwide distribution of these human retroviruses reside in an effective prevention of viral diffusion, possibly by vaccination, and of the onset of disease in virus-positive subjects. The possibility is discussed of defining protocols to prevent the development of clinical disease. These protocols could be based on pharmacological reconstitution of host's immune reactivity, that is altered early after infection with these retroviruses, and on the control of virus replication by antiviral therapy.

Mononuclear cells from peripheral blood of adult donors and from cord blood are equally protected by alpha- and beta-interferons against infection with HTLV-I

Human mononuclear cells derived from peripheral blood of adult donors (PBMC) or from neonatal cord blood (CBMC) were found to be equally sensitive to the protective effect of alpha- and beta-interferons (IFNs) against the infection with HTLV-I during long-term culture. The effect of IFNs was evidenced by a remarkable reduction of the number of virus-positive cells during culture as evaluated by indirect immunofluorescence for the p19 virus core protein. Moreover, the appearance of p19-positive immortalized clones was inhibited by IFNs in PBMC co-cultures, whereas it was delayed in CBMC cultures. These kinetics are in relation with the higher permissivity of CBMC to the virus in comparison with PBMC, since in CBMC cultures infected cells can be clearly detected starting already 1 week post-infection (p.i.), whereas in PBMC cultures their appearance time is approximately at the 6th week p.i. IFNs acted by 'priming' PBMC and CBMC to an active antiviral competence, since one single treatment with 1000 IU/ml of alpha- or beta-IFN at the onset of the co-culture of mononuclear cells with irradiated virus-donor cells was able to maintain very low levels of infection for approximately 6 weeks in CBMC cultures and at least for 18 weeks in PBMC cultures. As a consequence, it seems likely that IFN action is mediated by the expression of a defined, although not completely identified, set of genes in the host cells.

Selection of HTLV-I positive clones is prevented by prostaglandin A in infected cord blood cultures

Type A prostaglandins (PGA1 and 16,16-dimethyl-PGA2-methyl ester) were found to block the proliferation of HTLV-I infected cord blood lymphocytes (CBL) in vitro, thus preventing the clonal immortalisation that is considered as a predisposing condition to HTLV-I positive leukaemia. PGA1 and di-M-PGA2 did not affect the long-term survival of normal non-infected CBL, whereas they suppressed the proliferation of an established cord-blood derived HTLV-I positive cell line, MT-2. As shown by the number of HTLV-I infected p19+ cells, the block of the selection of immortalised, infected clones by PGAs did not appear to be due to an inhibition of early stages of HTLV-I infection. The possibility that the effect of PGAs could be mediated by an action on the immune response was also examined. PGAs regulated the cell-mediated cytotoxic function of CBL to a different extent when normal non-infected or HTLV-I exposed CBL were compared. In fact, PGAs down-regulated the natural killing and macrophage/lymphocyte cytotoxic response of normal CBL, whereas they did not modify the already depressed immune response of CBL challenged with HTLV-I. These results suggest that the protective effect of PGAs against HTLV-I infection in vitro is mostly related to the direct suppression of the clonal expansion of virus-infected cells, rather than to the anti-viral activity or modulation of the cell-mediated immunity.

Modulation of the cell-mediated immune function by interferon alpha, beta or gamma can partially reverse the immunosuppression induced by human T-cell leukemia virus I in human cord blood cultures

Infection with human T-cell leukemia virus type I (HTLV-I) is associated in vitro and in vivo with a remarkable depression of cell-mediated immune functions. In the present report it is shown that early events following virus-induced suppression of the cell-mediated immune response of freshly isolated cord blood mononuclear cells (CBL) infected with HTLV-I can be partially counteracted by treatment with interferons alpha, beta or gamma (IFN). All three types of IFN exerted a protective effect on CBL cultures exposed to the virus. This resulted in: (a) a reduced number of virus-positive cells until 4 weeks of culture; (b) delay in the clonal expansion of infected cells (IFN alpha and gamma); (c) increased natural killer cell activity of CBL, 1 week post-infection (p.i.), mediated by IFN gamma; (d) increase of allospecific recognition of infecting and priming HTLV-I donor MT-2 cells by CBL in a cytotoxic-T-lymphocyte-like response, mediated by IFN and particularly by IFN gamma; (e) phenotype distribution of CBL subpopulations, tested 4 days p.i., more similar to that of non-infected CBL cultures. In contrast, the overall CBL proliferation, that is profoundly depressed during the first week p.i., was not restored by IFN treatments, suggesting that boosting of the cell-mediated killing induced by IFN might involve the maturation of undifferentiated precursor cells rather than stimulation of their proliferation. The improvement of the efficiency of the antiviral immune response induced by treatment with IFN is likely to contribute to the clearance of virus-positive cells during the early phase of infection. This would provide experimental evidence to support an immunopharmacological approach contributing to the conversion of HTLV-I carriers from positive to negative.

Depression of early phase of HTLV-I infection in vitro mediated by human beta-interferon

Natural human interferon beta (beta-IFN) was tested during the early phase of in vitro infection with HTLV-I virus of human cord blood mononuclear cells (CBL), to evaluate whether its antiviral and immunomodulating effects might prevent spreading of infection in the host. beta-IFN was found to reduce HTLV-I transmission and integration in CBL cultures. Moreover, beta-IFN had no effect in preventing virus transmission and integration in K562 and a very limited effect in HL60 and Molt-4 human tumour lines, suggesting a cell-type specific mode of action. beta-IFN induced a 'priming' response on CBL, since overnight pretreatment of recipient cells or one single treatment at the onset of the coculture were almost equally effective in protecting against HTLV-I infection. During the early days post infection (p.i.), IFN-treated CBL showed a pattern of phenotypic markers that was closer to that of non-infected CBL. In contrast, untreated CBL exposed to HTLV-I showed a percent increase of Tac+, M3+ and Leu 11+ subpopulations. Cell-mediated immune responses of CBL were depressed after coculturing with HTLV-I producer MT-2 cells. beta-IFN was able to boost the cell-mediated cytotoxicity of fresh and infected CBL against both K562 and MT-2 target cells. Leukocyte blastogenesis in mixed lymphocyte/tumour cell cultures, evaluated in terms of 3H-thymidine incorporation during the first week p.i., was also enhanced by IFN when macrophages and lymphocytes were reconstituted at an optimal 1:20 ratio. It is conceivable that this overall enhancement of the immune response induced by beta-IFN could contribute to reduce HTLV-I infection in vitro.

Low concentrations of suramin can reduce in vitro infection of human cord blood lymphocytes with HTLV-I during long-term culture

In vitro infection of human cord blood lymphocytes (CBL) with human T-cell leukemia/lymphoma virus type I (HTLV-I) was found to be reduced by suramin treatment at a concentration ranging from 10-100 micrograms/ml. At higher concentrations (500 micrograms/ml) suramin was toxic to the cells and even resulted in an increased percentage of cells positive for the p19 viral core protein. Suramin treatment at the onset of the CBL coculture with a lethally irradiated HTLV-I donor cell line (MT-2) reduced virus transmission, evaluated as number of p19+ cells, and the consequent amount of integrated provirus in the host genome. The amount of viral RNA transcripts was not reduced in CBL cocultures. On the other hand, suramin affected HTLV-I replication in infected MT-2 cells, when used at a concentration of 50 micrograms/ml, and this might contribute to the reduced infectivity of suramin-treated MT-2 cells. In addition to its antiviral effects, suramin exerted a modest positive regulation on the natural killing activity of CBL and their early proliferative response in mixed lymphocyte/tumor cell culture.