Application of scanning electron microscopy for diagnosing phytoplasmas in single and mixed (virus-phytoplasma ) infection in Papaya

Phytoplasma and some viruses, papaya ring spot (PRSV) and papaya mosaic (PapMV) have been reported in papaya, from different Mexican states. Some symptoms of yellow type diseases, such as mosaics, stunting, bunchy top and leaf chlorosis, necrosis and malformations are somewhat similar in appearance, but caused by distinct pathogens. Using a scanning electron microscopy (SEM) technique phytoplasmas were detected in the phloem tissues of field and greenhouse-indexed papaya plants from Baja California Sur (BCS). Samples from 32 local varieties, as well as cv. Maradol, showing numerous symptoms of dieback, mosaics, bunchy top, and yellow crinkle were analyzed. The pathogen was detected in stems, leafstalks, roots, axillary leaflets, leaf veins and flowers. Phytoplasma was also detected in dry and in germinated seeds within the fruit, suggesting seed transmission of the pathogen. Some ultrastructural peculiarities of phytoplasma in infected tissues were also observed. No viral infection with PRSV and PapMV was revealed neither in test-plants nor by molecular techniques. Application of SEM technique for analysis of papaya samples from Veracruz and Irapuato, both from field-grown and mechanically inoculated plants with PRSV and PapMV in various combinations also revealed phytoplasmas in the phloem of most of tested samples. In some cases, along with phytoplasmas, rod-shaped bacteria were distinguished.Keywords: Papaya, phytoplasma, papaya ringspot virus, papaya mosaic virus, scanning electron microscopy, Mexic

Alteration of the unfolded protein response modifies neurodegeneration in a mouse model of Marinesco–Sjögren syndrome

Endoplasmic reticulum (ER) stress has been linked to the onset and progression of many diseases. SIL1 is an adenine nucleotide exchange factor of the essential ER lumen chaperone HSPA5/BiP that senses ER stress and is involved in protein folding. Mutations in the Sil1 gene have been associated with Marinesco–Sjögren syndrome, hallmarks of which include ataxia and cerebellar atrophy. We have previously shown that loss of SIL1 function in mouse results in ER stress, ubiquitylated protein inclusions, and degeneration of specific Purkinje cells in the cerebellum. Here, we report that overexpression of HYOU1/ORP150, an exchange factor that works in parallel to SIL1, prevents ER stress and rescues neurodegeneration in Sil1−/− mice, whereas decreasing expression of HYOU1 exacerbates these phenotypes. In addition, loss of DNAJC3/p58IPK, a co-chaperone that promotes ATP hydrolysis by BiP, ameliorates ER stress and neurodegeneration in Sil1−/− mice. These findings suggest that alterations in the nucleotide exchange cycle of BiP cause ER stress and neurodegeneration in Sil1-deficient mice. Our results present the first evidence of important genetic modifiers of Marinesco–Sjögren syndrome, and provide additional pathways for therapeutic intervention for this, and other ER stress-induced, diseases

Vermiculite bio-barriers for Cu and Zn remediation: an eco-friendly approach for freshwater and sediments protection

The increase in heavy metal contamination in freshwater systems causes serious environmental problems in most industrialized countries, and the effort to find ecofriendly techniques for reducing water and sediment contamination is fundamental for environmental protection. Permeable barriers made of natural clays can be used as low-cost and eco-friendly materials for adsorbing heavy metals from water solution and thus reducing the sediment contamination. This study discusses the application of permeable barriers made of vermiculite clay for heavy metals remediation at the interface between water and sediments and investigates the possibility to increase their efficiency by loading the vermiculite surface with a microbial biofilm of Pseudomonas putida, which is well known to be a heavy metal accumulator. Some batch assays were performed to verify the uptake capacity of two systems and their adsorption kinetics, and the results indicated that the vermiculite bio-barrier system had a higher removal capacity than the vermiculite barrier (?34.4 and 22.8 % for Cu and Zn, respectively). Moreover, the presence of P. putida biofilm strongly contributed to fasten the kinetics of metals adsorption onto vermiculite sheets. In open-system conditions, the presence of a vermiculite barrier at the interface between water and sediment could reduce the sediment contamination up to 20 and 23 % for Cu and Zn, respectively, highlighting the efficiency of these eco-friendly materials for environmental applications. Nevertheless, the contribution of microbial biofilm in open-system setup should be optimized, and some important considerations about biofilm attachment in a continuous-flow system have been discussed.This work has been produced thanks to the collaboration of Dip.SA (University of Bologna) and IBB (University of Minho). A particular acknowledgment is due to Dr. E. Rosales. The work was partially financed by the FCT Strategic Project Pest-OE/EQB/LA0023 and the Project ‘‘BioEnv—Biotechnology and Bioengineering for a sustainable world,’’ co-funded by the Programa Operacional Regional do Norte (ON.2–O Novo Norte), QREN, FEDER

Cutting Edge:Transcriptional profiling reveals multifunctional and cytotoxic antiviral responses of zika virus-specific CD8 + T cells

Zika virus (ZIKV) constitutes an increasing public health problem. Previous studies have shown that CD8 + T cells play an important role in ZIKV-specific protective immunity. We have previously defined antigenic targets of the ZIKV-specific CD8 + T cell response in humans. In this study, we characterized the quality and phenotypes of these responses by a combined use of flow cytometry and transcriptomic methods, using PBMCs from donors deriving from different geographical locations collected in the convalescent phase of infection. We show that ZIKVspecific CD8 + T cells are characterized by a polyfunctional IFN-g signature with upregulation of TNF-a, TNF receptors, and related activation markers, such as CD69, as well as a cytotoxic signature characterized by strong upregulation of GZMB and CRTAM. The signature is stable and not influenced by previous dengue virus exposure, geographical location, or time of sample collection postinfection. To our knowledge, this work elucidates the first in-depth characterization of human CD8 + T cells responding to ZIKV infection

Peripheral T-lymphocytes express WNT7A and its restoration in leukemia-derived lymphoblasts inhibits cell proliferation

<p>Abstract</p> <p>Background</p> <p>WNT7a, a member of the Wnt ligand family implicated in several developmental processes, has also been reported to be dysregulated in some types of tumors; however, its function and implication in oncogenesis is poorly understood. Moreover, the expression of this gene and the role that it plays in the biology of blood cells remains unclear. In addition to determining the expression of the <it>WNT7A </it>gene in blood cells, in leukemia-derived cell lines, and in samples of patients with leukemia, the aim of this study was to seek the effect of this gene in proliferation.</p> <p>Methods</p> <p>We analyzed peripheral blood mononuclear cells, sorted CD3 and CD19 cells, four leukemia-derived cell lines, and blood samples from 14 patients with Acute lymphoblastic leukemia (ALL), and 19 clinically healthy subjects. Reverse transcription followed by quantitative Real-time Polymerase chain reaction (qRT-PCR) analysis were performed to determine relative <it>WNT7A </it>expression. Restoration of WNT7a was done employing a lentiviral system and by using a recombinant human protein. Cell proliferation was measured by addition of WST-1 to cell cultures.</p> <p>Results</p> <p>WNT7a is mainly produced by CD3 T-lymphocytes, its expression decreases upon activation, and it is severely reduced in leukemia-derived cell lines, as well as in the blood samples of patients with ALL when compared with healthy controls (<it>p </it>≤0.001). By restoring <it>WNT7A </it>expression in leukemia-derived cells, we were able to demonstrate that WNT7a inhibits cell growth. A similar effect was observed when a recombinant human WNT7a protein was used. Interestingly, restoration of <it>WNT7A </it>expression in Jurkat cells did not activate the canonical Wnt/β-catenin pathway.</p> <p>Conclusions</p> <p>To our knowledge, this is the first report evidencing quantitatively decreased <it>WNT7A </it>levels in leukemia-derived cells and that <it>WNT7A </it>restoration in T-lymphocytes inhibits cell proliferation. In addition, our results also support the possible function of <it>WNT7A </it>as a tumor suppressor gene as well as a therapeutic tool.</p

Patients with primary immunodeficiencies are a reservoir of poliovirus and a risk to polio eradication

ABSTARCT: Immunodeficiency-associated vaccine-derived polioviruses (iVDPVs) have been isolated from primary immunodeficiency (PID) patients exposed to oral poliovirus vaccine (OPV). Patients may excrete poliovirus strains for months or years; the excreted viruses are frequently highly divergent from the parental OPV and have been shown to be as neurovirulent as wild virus. Thus, these patients represent a potential reservoir for transmission of neurovirulent polioviruses in the post-eradication era. In support of WHO recommendations to better estimate the prevalence of poliovirus excreters among PIDs and characterize genetic evolution of these strains, 635 patients including 570 with primary antibody deficiencies and 65 combined immunodeficiencies were studied from 13 OPV-using countries. Two stool samples were collected over 4 days, tested for enterovirus, and the poliovirus positive samples were sequenced. Thirteen patients (2%) excreted polioviruses, most for less than 2 months following identification of infection. Five (0.8%) were classified as iVDPVs (only in combined immunodeficiencies and mostly poliovirus serotype 2). Non-polio enteroviruses were detected in 30 patients (4.7%). Patients with combined immunodeficiencies had increased risk of delayed poliovirus clearance compared to primary antibody deficiencies. Usually, iVDPV was detected in subjects with combined immunodeficiencies in a short period of time after OPV exposure, most for less than 6 months. Surveillance for poliovirus excretion among PID patients should be reinforced until polio eradication is certified and the use of OPV is stopped. Survival rates among PID patients are improving in lower and middle income countries, and iVDPV excreters are identified more frequently. Antivirals or enhanced immunotherapies presently in development represent the only potential means to manage the treatment of prolonged excreters and the risk they present to the polio endgame. Keywords: Poliovirus eradication, Immunodeficiency-associated vaccine-derived polioviruses, Oral poliovirus vaccine, Humoral immunodeficiency, Combined immunodeficiency, Primary immunodeficienc

Probiotic supplementation influences the diversity of the intestinal microbiota during early stages of farmed Senegalese sole (Solea senegalensis, Kaup, 1858)

Ingestion of bacteria at early stages results in establishment of a primary intestinal microbiota which likely undergoes several stages along fish life. The role of this intestinal microbiota regulating body functions is crucial for larval development. Probiotics have been proved to modulate this microbiota and exert antagonistic effects against fish pathogens. In the present study, we aimed to determine bacterial diversity along different developmental stages of farmed Senegalese sole (Solea senegalensis) after feeding probiotic (Shewanella putrefaciens Pdp11) supplemented diet for a short period (10–30 days after hatching, DAH). Intestinal lumen contents of sole larvae fed control and probiotic diets were collected at 23, 56, 87, and 119 DAH and DNA was amplified using 16S rDNA bacterial domain-specific primers. Amplicons obtained were separated by denaturing gradient gel electrophoresis (DGGE), cloned, and resulting sequences compared to sequences in GenBank. Results suggest that Shewanella putrefaciens Pdp11 induces a modulation of the dominant bacterial taxa of the intestinal microbiota from 23 DAH. DGGE patterns of larvae fed the probiotic diet showed a core of bands related to Lactobacillus helveticus, Pseudomonas acephalitica, Vibrio parahaemolyticus,and Shewanella genus, together with increased Vibri o genus presence. In addition, decreased number of clones related to Photobacterium damselae subsp piscicida at 23 and 56 DAH was observed in probiotic-fed larvae. A band corresponding to Shewanella putrefaciens Pdp11 was sequenced as predominant from 23 to 119 DAH samples, confirming the colonization by the probiotics. Microbiota modulation obtained via probiotics addition emerges as an effective tool to improve Solea senegalensis larviculture.En prens

Fcγ Receptors in Solid Organ Transplantation.

In the current era, one of the major factors limiting graft survival is chronic antibody-mediated rejection (ABMR), whilst patient survival is impacted by the effects of immunosuppression on susceptibility to infection, malignancy and atherosclerosis. IgG antibodies play a role in all of these processes, and many of their cellular effects are mediated by Fc gamma receptors (FcγRs). These surface receptors are expressed by most immune cells, including B cells, natural killer cells, dendritic cells and macrophages. Genetic variation in FCGR genes is likely to affect susceptibility to ABMR and to modulate the physiological functions of IgG. In this review, we discuss the potential role played by FcγRs in determining outcomes in solid organ transplantation, and how genetic polymorphisms in these receptors may contribute to variations in transplant outcome.MRC is supported by the NIHR Cambridge BRC, the NIHR Blood and Transplant Research Unit (Cambridge) and by a Medical Research Council New Investigator Grant (MR/N024907/1).This is the final version of the article. It first appeared from Springer via https://doi.org/10.1007/s40472-016-0116-