Lymphocyte activation as cytokine gene expression and secretion is related to the porcine reproductive and respiratory syndrome virus (PRRSV) isolate after in vitro homologous and heterologous recall of peripheral blood mononuclear cells (PBMC) from pigs vaccinated and exposed to natural infection

The present study evaluated the lymphocyte activation in PRRSV-vaccinated pigs subsequently exposed to natural infection by in vitro stimulation of peripheral blood mononuclear cells (PBMC) with homologous vaccine and two heterologous PRRSV isolates. The responsiveness was assessed by determining IFN-γ secreting cells by ELISpot assay, lymphocyte CD8 phenotype by intracellular staining/flow cytometry, cytokine gene expression by real-time quantitative PCR and cytokine secretion by ELISA. Conventional pigs were weaned at 28 days of age and inoculated intramuscularly (IM) or needle-less intradermally (ID) with a modified-live PRRSV vaccine suspended in adjuvant, while control pigs were injected with adjuvant alone (ADJ). Blood samples were collected at vaccination, 35 days post-vaccination and after 35 days post-exposure to natural infection by a heterologous field strain. Thirty-five days post-vaccination, PRRSV vaccine induced a low but significant virus-specific IFN-γ secreting cell response upon stimulation with both the vaccine strain and the two isolates in vaccinated pigs. Conversely, after 35 days post-exposure, only the vaccine strain and the BS/114/S isolate triggered this response. Intracellular staining showed that PRRSV-specific immune cells reacting upon vaccine strain and BS/114/S stimulation were mostly CD8⁺ IFN-γ producing cells whereas the stimulation with BS/55 isolate induced an IFN-γ production associated to the CD8^?IFN-γ⁺ phenotype. At 35 days post-vaccination, PBMC from vaccinated pigs showed lower IL-10 expression and release, and higher TNF-α gene expression upon stimulation with both the vaccine and viral isolates. After infection, both cytokines were not differently modulated in different groups. Immune parameters give evidence that IFN-γ secreting cells in the peripheral blood can be elicited upon PRRSV infection although vaccination itself does not stimulate high levels of these reactive cells. Moreover, the cross-reactivity against divergent PRRS viruses can show a different intensity and be differently associated with cytotoxic CD8⁺IFN-γ⁺ as well as CD8^?IFN-γ⁺ cells. Overall, the obtained data confirmed that the immune activation against PRRSV is not dependent on the genetic divergence of the virus. Especially after infection, a different immune reactivity was evident upon stimulation with the different isolates in terms of frequency and CD8 phenotype of PRRSV-specific IFN-γ producing cells. The modulation of cytokines in vaccinated pigs appeared to be more dependent on vaccination or infection conditions than on stimulation by different isolates, and the changes of IL-10 more relevant than those of TNF-α at gene and protein levels. Moreover, under the conditions of this study, the PRRSV vaccine administered via the intradermal route by a needle-less device was confirmed to induce an immune response comparable or in some cases higher than the intramuscular route.     

Polycyclic Aromatic Hydrocarbons, Polychlorinated Biphenyls and Trace Metals in Sediments from a Coastal Lagoon (Northern Adriatic, Italy)

Surface sediments (0–5 cm) were analysed to provide information on levels, spatial trends and sources of the 16 USEPA polycyclic aromatic hydrocarbons (PAH), 15 polychlorinated biphenyls (PCBs) and trace metals (copper, chromium, mercury, nickel and zinc) in channel and wetland habitats of Pialassa Baiona lagoon (Italy). The highest levels of PAHs, PCBs and Hg (3,032–87,150, n.d.–3,908 and 1.3–191 mg kg⁻¹) were mainly found at channel habitats close to industrial sources. Pyrogenic PAH inputs were significant, with a predominance of four-ring PAHs and combustion-related PAHs in both channel and wetland habitats. Among PCB congeners, chlorination class profiles show that penta- and hexachlorinated PCBs are the most prevalent homologues accounting for approximately 33% and 47% of the total PCB concentrations in channel sediments. Total toxicity equivalent factors (TEQs) of potentially carcinogenic PAHs varied from 348 to 7,879 μg kg⁻¹ and from 4.3 to 235 μg kg⁻¹ in channel and wetland sediments; calculated TEQs for dioxin-like PCB congeners at channel habitats ranged from n.d. to 86.7 μg kg⁻¹. Comparison of PAHs, PCBs and metal levels with Sediment Quality Guidelines suggests that more concern should be given to the southern area of the lagoon for potential risks of carcinogenic PAHs, dioxin-like PCBs and mercury.     

Effects of long-term exposure to enriched CO<Subscript>2</Subscript> on the nutrient-supplying capacity of a grassland soil

Altered soil nutrient cycling under future climate scenarios may affect pasture production and fertilizer management. We conducted a controlled-environment study to test the hypothesis that long-term exposure of pasture to enriched carbon dioxide (CO₂) would lower soil nutrient availability. Perennial ryegrass was grown for 9 weeks under ambient and enriched (ambient + 120 ppm) CO₂ concentrations in soil collected from an 11.5-year free air CO₂ enrichment experiment in a grazed pasture in New Zealand. Nitrogen (N) and phosphorus (P) fertilizers were applied in a full factorial design at rates of 0, 12.5, 25 or 50 kg N ha⁻¹ and 0, 17.5 or 35 kg P ha⁻¹. Compared to ambient CO₂, under enriched CO₂ without P fertilizer, total plant biomass did not respond to N fertilizer, and tissue N/P ratio was increased indicating that P was co-limiting. This limitation was alleviated with the lowest rate of P fertilizer (17.5 kg P ha⁻¹). Plant biomass in both CO₂ treatments increased with increasing N fertilizer when sufficient P was available. Greater inputs of P fertilizer may be required to prevent yield suppression under enriched CO₂ and to stimulate any response to N.     

Hydroponic cultivation improves the nutritional quality of soybean and its products

Hydroponic cultivation allows the control of environmental conditions, saves irrigation water, increases productivity, and prevents plant infections. The use of this technique for large commodities such as soybean is not a relevant issue on fertile soils, but hydroponic soybean cultivation could provide proteins and oil in adverse environmental conditions. In this paper, the compositions of four cultivars of soybean seeds and their derivates, soy milk and okara, grown hydroponically were compared to that of the same cultivar obtained from soil cultivation in an open field. Besides proximal composition, the concentrations of phytic acid and isoflavones were monitored in the seeds, soy milk, and okara. Results demonstrated that, independent from the cultivar, hydroponic compared to soil cultivation promoted the accumulation of fats (from 17.37 to 21.94 g/100 g dry matter) and total dietary fiber (from 21.67 to 28.46 g/100 g dry matter) and reduced isoflavones concentration (from 17.04 to 7.66 mg/kg dry matter), whereas protein concentration was unaffected. The differences found in seed composition were confirmed in the respective okara products, but the effect of cultivation system was not significant looking at the soy milk composition. Data showed that hydroponic cultivation improved the nutritional quality of soybean seeds with regard to fats and dietary fiber. They also suggest that specific cultivars should be selected to obtain the desired nutritional features of the soybean raw material depending on its final destination.     

Photochemical damage and comparative performance of superoxide dismutase and ascorbate peroxidase in sugarcane leaves exposed to paraquat-induced oxidative stress

The physiological responses of sugarcane (Saccharum officinarum L.) to oxidative stress induced by methyl viologen (paraquat) were examined with respect to photochemical activity, chlorophyll content, lipid peroxidation and superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities. Thirty-day-old sugarcane plants were sprayed with 0, 2, 4, 6 and 8 mM methyl viologen (MV). Chlorophyll fluorescence was measured after 18 h and biochemical analyses were performed after 24 and 48 h. Concentrations of MV above 2 mM caused significant damage to photosystem II (PSII) activity. Potential and effective quantum efficiency of PSII and apparent electron transport rate were greatly reduced or practically abolished. Both chlorophyll and soluble protein contents steadily decreased with MV concentrations above 2 mM after 24 h of exposure, which became more pronounced after 48 h, achieving a 3-fold decrease. Insoluble protein contents were little affected by MV. Oxidative stress induced by MV was evidenced by increases in lipid peroxidation. Specific activity of SOD increased, even after 48 h of exposure to the highest concentrations of MV, but total activity on a fresh weight basis did not change significantly. Nondenaturing PAGE assayed with H₂O₂ and KCN showed that treatment with MV did not change Cu/Zn-SOD and Mn-SOD isoform activities. In contrast, APX specific activity increased at 2 mM MV but then dropped at higher doses. Oxidative damage induced by MV was inversely related to APX activity. It is suggested that the major MV-induced oxidative damages in sugarcane leaves were related to excess H₂O₂, probably in chloroplasts, caused by an imbalance between SOD and APX activities, in which APX was a limiting step. Reduced photochemical activity allowed the early detection of the ensuing oxidative stress.     

Sponges and Their Symbionts as a Source of Valuable Compounds in Cosmeceutical Field

In the last decades, the marine environment was discovered as a huge reservoir of novel bioactive compounds, useful for medicinal treatments improving human health and well-being. Among several marine organisms exhibiting biotechnological potential, sponges were highlighted as one of the most interesting phyla according to a wide literature describing new molecules every year. Not surprisingly, the first marine drugs approved for medical purposes were isolated from a marine sponge and are now used as anti-cancer and anti-viral agents. In most cases, experimental evidence reported that very often associated and/or symbiotic communities produced these bioactive compounds for a mutual benefit. Nowadays, beauty treatments are formulated taking advantage of the beneficial properties exerted by marine novel compounds. In fact, several biological activities suitable for cosmetic treatments were recorded, such as anti-oxidant, anti-aging, skin whitening, and emulsifying activities, among others. Here, we collected and discussed several scientific contributions reporting the cosmeceutical potential of marine sponge symbionts, which were exclusively represented by fungi and bacteria. Bioactive compounds specifically indicated as products of the sponge metabolism were also included. However, the origin of sponge metabolites is dubious, and the role of the associated biota cannot be excluded, considering that the isolation of symbionts represents a hard challenge due to their uncultivable features.