An exceptional family: Ophiocordyceps‐allied fungus dominates the microbiome of soft scale insects (Hemiptera: Sternorrhyncha: Coccidae)

Hemipteran insects of the suborder Sternorrhyncha are plant sap feeders, where each family is obligately associated with a specific bacterial endosymbiont that produces essential nutrients lacking in the sap. Coccidae (soft scale insects) is the only major sternorrhynchan family in which obligate symbiont(s) have not been identified. We studied the microbiota in seven species from this family from Israel, Spain and Cyprus, by high‐throughput sequencing of ribosomal genes, and found that no specific bacterium was prevalent and abundant in all the tested species. In contrast, an Ophiocordyceps‐allied fungus sp.—a lineage widely known as entomopathogenic—was highly prevalent. All individuals of all the tested species carried this fungus. Phylogenetic analyses showed that the Ophiocordyceps‐allied fungus from the coccids is closely related to fungi described from other hemipterans, and they appear to be monophyletic, although the phylogenies of the Ophiocordyceps‐allied fungi and their hosts do not appear to be congruent. Microscopic observations show that the fungal cells are lemon‐shaped, are distributed throughout the host's body and are present in the eggs, suggesting vertical transmission. Taken together, the results suggest that the Ophiocordyceps‐allied fungus may be a primary symbiont of Coccidae—a major evolutionary shift from bacteria to fungi in the Sternorrhyncha, and an important example of fungal evolutionary lifestyle switch.     

Enhanced Erythrocyte Adhesiveness/Aggregation in Obesity Corresponds to Low‐Grade Inflammation

Objective: Previous studies have suggested that obesity enhances the inflammatory response, producing macromolecules involved in the induction and/or maintenance of increased erythrocyte aggregation. The objectives of this study were to evaluate the correlation between inflammation markers, erythrocyte adhesiveness/aggregation, and the degree of obesity and to assess phosphatidylserine expression on erythrocyte surface membrane of obese vs. nonobese individuals. Research Methods and Procedures: Erythrocyte adhesiveness/aggregation in the peripheral venous blood was evaluated by using a new biomarker, phosphatidylserine expression was assessed by means of flow cytometry, and markers of inflammation were measured in 65 subjects: 30 obese [body mass index (BMI) = 41 ± 7.7 kg/m²] and 35 nonobese (BMI = 24 ± 2.7 kg/m²) individuals. Pearson correlations and Student's t test were performed. Results: A highly significant difference was noted in the degree of erythrocyte adhesiveness/aggregation and markers of inflammation between the study groups. BMI correlated with erythrocyte adhesiveness/aggregation (r = 0.42, p = 0.001), erythrocyte sedimentation rate (r = 0.42, p = 0.001), high‐sensitive C‐reactive protein (r = 0.55, p < 10^?4), fibrinogen (r = 0.37, p = 0.004), and white blood cell count (r = 0.45, p < 10^?4). The degree of erythrocyte adhesiveness/aggregation correlated with erythrocyte sedimentation rate (r = 0.5, p < 10^?4), high‐sensitive C‐reactive protein (r = 0.56, p < 10^?4), fibrinogen (r = 0.54, p < 10^?4), and white blood cell count (r = 0.32, p = 0.01). Discussion: Our results suggest that obesity‐related erythrocyte adhesiveness/aggregation is probably mediated through increased concentrations of adhesive macromolecules in the circulation and not necessarily through hyperlipidemia or phosphatidylserine exposure on erythrocyte's membrane.     

Mesenchymal stromal cells revert multiple myeloma cells to less differentiated phenotype by the combined activities of adhesive interactions and interleukin-6

Multiple myeloma is characterized by the malignant growth of immunoglobulin producing plasma cells, predominantly in the bone marrow. The effects of primary human mesenchymal stromal cells on the differentiation phenotype of multiple myeloma cells were studied by co-culture experiments. The incubation of multiple myeloma cells with bone marrow-derived mesenchymal stromal cells resulted in significant reduction of the expression of the predominant plasma cell differentiation markers CD38 and CD138, and cell surface immunoglobulin light chain. While the down-regulation of CD138 by stromal cells was completely dependent on their adhesive interactions with the multiple myeloma cells, interleukin-6 induced specific down-regulation of CD38. Mesenchymal stromal cells or their conditioned media inhibited the growth of multiple myeloma cell line, thereby reducing the overall amounts of secreted light chains. Analysis of primary multiple myeloma bone marrow samples reveled that the expression of CD38 on multiple myeloma cells was not affected by adhesive interactions. The ex vivo propagation of primary multiple myeloma cells resulted in significant increase in their differentiation markers. Overall, the data indicate that the bone marrow-derived mesenchymal stromal cells revert multiple myeloma cells to less differentiated phenotype by the combined activities of adhesive interactions and interleukin-6.     

alpha2,6-Sialylation promotes binding of placental protein 14 via its Ca2+-dependent lectin activity: insights into differential effects on CD45RO and CD45RA T cells

Placental protein 14 (PP14; glycodelin) is a pregnancy-associated immunoregulatory protein that is known to inhibit T cells via T-cell receptor desensitization. The recent demonstration of PP14 as lectin has provided insight into how it may mediate its CD45 glycoprotein-dependent T-cell inhibition. In this study, we have investigated PP14's lectin-binding properties in detail. Significantly, PP14 reacts with N-acetyllactosamine (LacNAc) as was also found for members of the galectin family, such as the potent immunoregulatory protein, galectin-1. However, in contrast to galectin-1, PP14's binding is significantly enhanced by alpha2,6-sialylation and also by the presence of cations. This was demonstrated by preferential binding to fetuin as compared with its desialylated variant asialofetuin (ASF) and by using free alpha2,6- versus alpha2,3-sialylated forms of LacNAc in competitive inhibition and direct solid-phase binding assays. Interestingly, from immunological point of view, PP14 also binds differentially to CD45 isoforms known to differ in their degree of sialylation. PP14 preferentially inhibits CD45RA+, as compared with CD45RO+ T cells, and preferentially co-capped this variant CD45 on the T-cell surface. Finally, we demonstrate that PP14 promotes CD45 dimerization and clustering, a phenomenon that may regulate CD45 activity.     

Transgenic organisms expressing genes from Bacillus thuringiensis to combat insect pests

Various subspecies (ssp.) of Bacillus thuringiensis (Bt) are considered the best agents known so far to control insects, being highly specific and safe, easily mass produced and with long shelf life.1 The para-crystalline body that is produced during sporulation in the exosporium includes polypeptides named δ-endotoxins, each killing a specific set of insects. The different entomopathogenic toxins of various Bt ssp. can be manipulated genetically in an educated way to construct more efficient transgenic bacteria or plants that express combinations of toxin genes to control pests.2 Joint research projects in our respective laboratories during the last decade demonstrate what can be done by implementing certain ideas using molecular biology with Bt ssp. israelensis (Bti) as a model system. Here, we describe our progress achieved with Gram-negative bacterial species, including cyanobacteria, and some preliminary experiments to form transgenic plants, mainly to control mosquitoes (Diptera), but also a particular Lepidopteran and Coleopteran pest species. In addition, a system is described by which environment-damaging genes can be removed from the recombinants thus alleviating procedures for obtaining permits to release them in nature.     

Characterization of <Emphasis Type="Italic">fs10.1</Emphasis>, a major QTL controlling fruit elongation in <Emphasis Type="Italic">Capsicum</Emphasis>

We previously identified fs10.1 as a major QTL controlling fruit shape (index of length to width) in an interspecific F₂ cross of Capsicum annuum (round fruit) × C. chinense (elongated fruit) in pepper. To more precisely map and characterize the QTL, we constructed near-isogenic lines for fs10.1 and mapped it in a BC₄F₂ population. In this population, fs10.1 segregated as a Mendelian locus and mapped 0.3 cM away from the closest molecular marker. We further verified the effect of fs10.1 in an F₂ population from an independent cross between elongated- and conical-fruited parents. To identify additional allelic variation at fruit shape loci, we screened an EMS-mutagenized population of the blocky-fruited cv. Maor and identified the mutant E-1654 with elongated fruit. This fruit shape mutation was mapped to the fs10.1 region and was determined to be allelic to the QTL. By measuring fruit shape of near-isogenic lines for fs10.1 during fruit development, we found that the shape of the fruit is determined primarily in the first 2 weeks after anthesis. Histological measurements of cell size and cell shape in pericarp sections of fruits of the isogenic lines throughout fruit development indicated that the shape of the fruit is determined primarily by cell shape and that the development of fruit shape is correlated with cell shape.     

Glucose Kinetics in the Collagen-Induced Arthritis Model: An All-in-One Model to Assess Both Efficacy and Metabolic Side Effects of Glucocorticoids

Prednisolone and other glucocorticoids (GCs) are potent anti-inflammatory drugs, but chronic use is hampered by metabolic side effects. Therefore, there is an urgent medical need for improved GCs that are as effective as classical GCs but have a better safety profile. A well-established model to assess anti-inflammatory efficacy is the chronic collagen-induced arthritis (CIA) model in mice, a model with features resembling rheumatoid arthritis. Models to quantify undesired effects of glucocorticoids on glucose kinetics are less well-established. Recently, we have described a model to quantify basal blood glucose kinetics using stably-labeled glucose. In the present study, we have integrated this blood glucose kinetic model in the CIA model to enable quantification of both efficacy and adverse effects in one animal model. Arthritis scores were decreased after treatment with prednisolone, confirming the anti-inflammatory properties of GCs. Both inflammation and prednisolone induced insulin resistance as insulin secretion was strongly increased whereas blood glucose concentrations and hepatic glucose production were only slightly decreased. This insulin resistance did not directly resulted in hyperglycemia, indicating a highly adaptive compensatory mechanism in these mice. In conclusion, this ‘all-in-one’ model allows for studying effects of (novel) GC compounds on the development of arthritis and glucose kinetics in a single animal. This integrative model provides a valuable tool for investigating (drug-induced) metabolic dysregulation in an inflammatory setting.