Murine Cytomegalovirus m02 Gene Family Protects against Natural Killer Cell-Mediated Immune Surveillance

The murine cytomegalovirus m02 gene family encodes putative type I membrane glycoproteins named m02 through m16. A subset of these genes were fused to an epitope tag and cloned into an expression vector. In transfected and murine cytomegalovirus-infected cells, m02, m04, m05, m06, m07, m09, m10, and m12 localized to cytoplasmic structures near the nucleus, whereas m08 and m13 localized to a filamentous structure surrounding the nucleus. Substitution mutants lacking the m02 gene (SMsubm02) or the entire m02 gene family (SMsubm02-16) grew like their wild-type parent in cultured cells. However, whereas SMsubm02 was as pathogenic as the wild-type virus, SMsubm02-16 was markedly less virulent. SMsubm02-16 produced less infectious virus in most organs compared to wild-type virus in BALB/c and C57BL/6J mice, but it replicated to wild-type levels in the organs of immunodeficient gamma(c)/Rag2 mice, lacking multiple cell types including natural killer cells, and in C57BL/6J mice depleted of natural killer cells. These results argue that one or more members of the m02 gene family antagonize natural killer cell-mediated immune surveillance.     

<Emphasis Type="Italic">Teucrium polium</Emphasis> Complex with Molybdate Enhance Cultured Islets Secretory Function

Islet transplantation has become a promising treatment in the therapy of type 1 diabetes. Its function improvement, after isolation and before transplantation, is crucial because of their loss both in number and function of islets after isolation procedures. Trace elements sodium orthovanadate (SOV) and sodium molybdate (SM), as well as medicinal plant Teucrium polium L. (TP), showed and possessed high beneficial antioxidative potential and even hypoglycemic properties via their effect on islets. We evaluated the effect of these components in combination on cultured islet function in order to improve pancreatic islet transplantation. Rat pancreatic islets were cultured for 24 h then incubated with different concentrations of TP (0.01 and 0.1 mg/mL) alone and in combination with SOV (1 mM) or SM (1 mM). Insulin concentration in buffer media was measured as islet secretory function. Administration of TP (0.01 mg/mL), SM, and SOV alone or in combination with each other significantly increased insulin secretion at high glucose concentration (16.7 mM); insulin secretion was significantly greater in the group containing both TP and SM than other treated groups (p < 0.05). The combination of the mentioned trace elements especially molybdate with TP could improve islet cells function before transplantation.     

Plasma Biomarkers Discriminate Clinical Forms of Multiple Sclerosis

Multiple sclerosis, the most common cause of neurological disability in young population after trauma, represents a significant public health burden. Current challenges associated with management of multiple sclerosis (MS) patients stem from the lack of biomarkers that might enable stratification of the different clinical forms of MS and thus prompt treatment for those patients with progressive MS, for whom there is currently no therapy available. In the present work we analyzed a set of thirty different plasma cytokines, chemokines and growth factors present in circulation of 129 MS patients with different clinical forms (relapsing remitting, secondary progressive and primary progressive MS) and 53 healthy controls, across two independent cohorts. The set of plasma analytes was quantified with Luminex xMAP technology and their predictive power regarding clinical outcome was evaluated both individually using ROC curves and in combination using logistic regression analysis. Our results from two independent cohorts of MS patients demonstrate that the divergent clinical and histology-based MS forms are associated with distinct profiles of circulating plasma protein biomarkers, with distinct signatures being composed of chemokines and growth/angiogenic factors. With this work, we propose that an evaluation of a set of 4 circulating biomarkers (HGF, Eotaxin/CCL11, EGF and MIP-1β/CCL4) in MS patients might serve as an effective tool in the diagnosis and more personalized therapeutic targeting of MS patients.     

Targeting Homologous Recombination in Notch-Driven C. elegans Stem Cell and Human Tumors

Mammalian NOTCH1-4 receptors are all associated with human malignancy, although exact roles remain enigmatic. Here we employ glp-1(ar202), a temperature-sensitive gain-of-function C. elegans NOTCH mutant, to delineate NOTCH-driven tumor responses to radiotherapy. At ≤20°C, glp-1(ar202) is wild-type, whereas at 25°C it forms a germline stem cell⁄progenitor cell tumor reminiscent of human cancer. We identify a NOTCH tumor phenotype in which all tumor cells traffic rapidly to G2⁄M post-irradiation, attempt to repair DNA strand breaks exclusively via homology-driven repair, and when this fails die by mitotic death. Homology-driven repair inactivation is dramatically radiosensitizing. We show that these concepts translate directly to human cancer models.     

Etiology and Transmission of Sesame Phyllody in Iran

Phyllody is a destructive disease of sesame (Sesamum indicum L.) in Iran. The major symptoms of the disease are floral virescence, phyllody and proliferation. Other symptoms which sometimes accompany the disease are yellowing, cracking of seed capsules, germination of seeds in the capsules and formation of dark exudates on the foliage. Light microscopy of hand-cut sections of sesame and colza (Brassica napus L. cv. Oro) stems treated with Dienes' stain showed blue areas in the phloem region of phyllody infected plants. Mycoplasma-like bodies were found in the sieve cells of infected sesame stems when thin sections were examined m an electron microscope. Sesame phyllody was successfully transmitted from sesame to sesame by grafting. Among various leafhoppers collected in sesame fields only Neoaliturus haematoceps transmitted the disease. This is the first report on the identification of a Mycoplasma-like organism (MLO) as the cause of sesame phyllody and N. haematoceps as an MLO vector in Iran. In host range studies using the leafhopper vector, only B. napus cv. Oro, Lepidium sativum, Catharanthus roseus, Lactuca sp. and Portulaca oleracea, but not 17 other species, developed symptoms. The species of vector and host range of MLO indicate that sesame phyllody in Iran is different from that reported in India and Upper Volta.     

Characterization of a monoclonal antibody to human proacrosin and its use in acrosomal status evaluation.

Among the monoclonal antibodies (MAb) selected after immunization of mice with a detergent-insoluble fraction from human spermatozoa, MAb 4D4 was found to stain in immunofluorescence the principal part of the acrosome of human spermatozoa. Acrosome reaction induced decreased and spotty 4D4 immunofluorescence staining. Immunoelectron microscopy before or after embedding revealed that the epitope defined by MAb 4D4 was sequestered in the anterior acrosomal matrix and, after the acrosome reaction, remained partly bound on matrix elements attached to the inner acrosomal membrane. Western blot analysis of sperm extracts showed that the epitope defined by MAb 4D4 was located on a 55 KD polypeptide in whole cells and on 55 and 50 KD polypeptides in non-ionic detergent fractions. Human proacrosin-enriched fraction obtained by FPLC purification exhibited several proteolytic activities against gelatin in gel enzymography: a 50 KD major band and two minor bands in the 20-30 KD area; the 50 KD polypeptide reacted with MAb 4D4 in Western blots. Furthermore, the 4D4-immunoprecipitated polypeptide from sperm extract showed that the 50 KD band exhibited proteolytic activity with an optimal pH at 8.0 that was strongly inhibited by soybean trypsin inhibitor and ZnCl2. MAb 4D4 also reacted with the acrosome of the monkey Macaca fascicularis but not with the acrosome of any of the other non-primate mammalian species examined so far. Various shape defects of the acrosomal principal region were revealed by 4D4 labeling of spermatozoa with head anomalies from infertile patients. MAb 4D4 also recognized proacrosin in paraffin-embedded human testis sections. These data make the monoclonal antiproacrosin antibody 4D4 an efficient tool for evaluation of the acrosomal status of human spermatozoa and spermatids.     

Effect of leukotrienes B4, C4, and D4 on segmental pulmonary vascular pressures

Leukotrienes (LTs) C4 and D4 are vasoconstrictors and are thought to increase both systemic and pulmonary vascular permeability. However, we and others have observed that LTC4 and LTD4 cause pulmonary vasoconstriction but do not increase the fluid filtration coefficient of excised guinea pig lungs perfused with a cell-depleted perfusate. To determine what vascular segments were exposed to an LT-induced increase in intravascular hydrostatic pressure we measured pulmonary arterial (Ppa), pulmonary arterial occlusion (Po,a), venous (Po,v) and double occlusion (Pdo) pressures in isolated guinea pig lungs perfused with a cell-depleted buffered salt solution before and after injecting 4 micrograms of LTB4, LTC4, or LTD4 into the pulmonary artery. All three LTs increased airway pressures and also increased Ppa, Po,a, and Pdo. Histamine (15 micrograms) as well as serotonin (20 or 200 micrograms) had the same effect. In excised rabbit lungs, histamine and serotonin increased only Ppa, and Po,a. LTC4 had no vasoactivity. There are marked species variations with regard to the activity and site of action of histamine, serotonin, and LTC4 on the pulmonary circulation.