Complexity of the supertypic HLA-DRw53 specificity: two distinct epitopes differentially expressed on one or all of the DR beta-chains depending on the HLA-DR allotype

The supertypic HLA-DRw53 specificity is associated with three allelic class II specificities defined by alloantisera: HLA-DR4, -DR7, and DRw9. The present study demonstrates the complexity of this supertypic DR specificity by comparing two DRw53-related determinants defined by the monoclonal antibodies PL3 and 109d6. For every HLA-DR4 cell line tested, both monoclonal antibodies were found to bind to the same subpopulation of DR molecules. This PL3+, 109d6+ DR subpopulation is also found on most, but not all, DR7+ cell lines with a beta-chain pattern that is identical to the beta-chain pattern of the PL3+, 109d6+ subpopulation on DR4 cell lines. However, some DR7+ cells which carry the HLA haplotype Bw57, DR7, DRw53, DQw3 were also found which completely lack the expression of the 109d6 determinant, but continue to express the PL3 determinant and some of the DRw53 determinants recognized by alloantisera. This results from the fact that the PL3 determinant is expressed on all of the DR molecules found on DR7 cells, including the distinct subpopulation of molecules that carry the HLA-DR7 determinant recognized by the monoclonal antibody SFR16-DR7. This PL3+, SFR16-DR7+ subpopulation does not carry the 109d6 determinant, demonstrating that the PL3 and 109d6 DRw53-related determinants are distinct and can be expressed on a different number of DR molecules, depending on the allotype of the cells. Blocking studies were also performed by using these monoclonal antibodies with alloreactive HLA-DR7-specific cytotoxic T cell clones. In these studies, the T cell-defined HLA-DR7 determinants were found to be carried by the same subpopulation of DR molecules recognized by the HLA-DR7-specific monoclonal antibody and not carried by the DR molecules recognized by 109d6. The DR7+ cell lines which do not express the 109d6 determinant also fail to express another supertypic determinant recognized by the monoclonal antibody IIIE3 carried on this molecule. Furthermore, no additional allelic forms of this unique DR beta-chain were found associated with the nonpolymorphic DR alpha-chain on these cells, suggesting that this DR beta-chain gene is not expressed. These cells also behave as homozygous typing cells for the Dw11 subtype of DR7 in HLA-D typing in the mixed lymphocyte culture assay. This suggests that the lack of expression of a specific class II gene may contribute additional genetic polymorphism within the known HLA-DR allotypes.     

Macrophage-derived factors increase low density lipoprotein uptake and receptor number in cultured human liver cells.

Recent evidence suggests the possibility that macrophages can influence lipoprotein metabolism. Therefore we investigated the ability of cultured macrophages to alter low density lipoprotein (LDL) uptake in a human liver cell line (HepG2). Conditioned media from phlogogenic-induced mouse peritoneal macrophages or from a human macrophage cell line stimulated with endotoxin increased HepG2 LDL uptake by as much as 60-70%. The increase was due, in part, to a significant macrophage-induced 40% increase in the number of LDL receptors per cell. Although macrophage conditioned media inhibited HepG2 cholesterol synthesis, the LDL receptor up-regulation did not appear to be due to the effects on cholesterol synthesis. The LDL receptor stimulatory activity was sensitive to proteolysis and heat. Its molecular mass was approximately 20 kDa based on gel filtration. Several macrophage secretory proteins were tested in HepG2 cultures for LDL uptake stimulation. Of these, oncostatin M (approximately 18 kDa by gel filtration) gave the strongest response. The rank order for LDL uptake stimulation was oncostatin M much greater than interleukin 6 = interleukin 1 = transforming growth factor-beta 1. A neutralizing antibody directed against oncostatin M inhibited the ability of conditioned media to up-regulate LDL receptors by 85%. Thus, our results indicate that macrophages can secrete several proteins that up-regulate LDL receptors in HepG2 cells and that most of the up-regulatory activity in macrophage conditioned media appears to be due to oncostatin M.     

An integrative approach to unravel the Ceratitis FAR (Diptera,Tephritidae) cryptic species complex: a review

This paper reviews all information gathered from different disciplines and studies to resolve the species status within the Ceratitis FAR (Ceratitis fasciventris, Ceratitis anonae, Ceratitis rosa) complex, a group of polyphagous fruit fly pest species (Diptera, Tephritidae) from Africa. It includes information on larval and adult morphology, wing morphometrics, cuticular hydrocarbons, pheromones, microsatellites, developmental physiology and geographic distribution. The general consensus is that the FAR complex comprises Ceratitis anonae, two species within Ceratitis rosa (so-called R1 and R2) and two putatitve species under Ceratitis fasciventris. The information regarding the latter is, however, too limited to draw final conclusions on specific status. Evidence for this recognition is discussed with reference to publications providing further details.     

Novel triazines as potent and selective phosphodiesterase 10A inhibitors

The identification of highly potent and orally active triazines for the inhibition of PDE10A is reported. The new analogs exhibit low-nanomolar potency for PDE10A, demonstrate high selectivity against all other members of the PDE family, and show desired drug-like properties. Employing structure-based drug design approaches, we investigated the selectivity of PDE10A inhibitors against other known PDE isoforms, by methodically exploring the various sub-regions of the PDE10A ligand binding pocket. A systematic assessment of the ADME and pharmacokinetic properties of the newly synthesized compounds has led to the design of drug-like candidates with good brain permeability and desirable drug kinetics (t(1/2), bioavailability, clearance). Compound 66 was highly potent for PDE10A (IC(50)=1.4nM), demonstrated high selectivity (>200×) for the other PDEs, and was efficacious in animal models of psychoses; reversal of MK-801 induced hyperactivity (MED=0.1mg/kg) and conditioned avoidance responding (CAR; ID(50)=0.2mg/kg).     

Surprising spectra of root-associated fungi in submerged aquatic plants

Similarly to plants from terrestrial ecosystems, aquatic species harbour wide spectra of root-associated fungi (RAF). However, comparably less is known about fungal diversity in submerged roots. We assessed the incidence and diversity of RAF in submerged aquatic plants using microscopy, culture-dependent and culture-independent techniques. We studied RAF of five submerged isoetid species collected in four oligotrophic freshwater lakes in Norway. Levels of dark septate endophytes (DSE) colonization differed among the lakes and were positively related to the organic matter content and negatively related to pH. In total, we identified 41 fungal OTUs using culture-dependent and culture-independent techniques, belonging to Mucoromycotina, Chytridiomycota, Glomeromycota, Ascomycota as well as Basidiomycota. Sequences corresponding to aquatic hyphomycetes (e.g. Nectria lugdunensis, Tetracladium furcatum and Varicosporium elodeae) were obtained. Eight arbuscular mycorrhizal taxa belonging to the orders Archaeosporales, Diversisporales and Glomerales were also detected. However, the vast majority of the fungal species detected (e.g. Ceratobasidium sp., Cryptosporiopsis rhizophila, Leptodontidium orchidicola, and Tuber sp.) have previously been known only from roots of terrestrial plants. The abundance and phylogenetic distribution of mycorrhizal as well as nonmycorrhizal fungi in the roots of submerged plants have reshaped our views on the fungal diversity in aquatic environment.     

Different growth response of five co-existing stoloniferous plant species to inoculation with native arbuscular mycorrhizal fungi

Five species of stoloniferous plants originating from the same field site (Galeobdolon montanum, Glechoma hederacea, Potentilla anserina, Ranunculus repens and Trifolium repens) were studied with respect to their interaction with arbuscular mycorrhizal (AM) fungi. More specifically, the question was addressed whether mycorrhizal growth response of host plant species could be related to their vegetative mobility. The roots of all the species examined were colonised with AM fungi in the field, with the percentage of colonisation varying among species from approximately 40% to 90%. In a subsequent pot experiment, plants of all the species were either left non-inoculated or were inoculated with a mixture of three native AM fungi isolated from the site of plant origin (Glomus mosseae, G. intraradices and G. microaggregatum). AM fungi increased phosphorus uptake in all the plant species; however, plant growth response to inoculation varied widely from negative to positive. In addition to the biomass response, AM inoculation led to a change in clonal growth traits such as stolon number and length or ramet number in some species. Possible causes of the observed differences in mycorrhizal growth response of various stoloniferous plants are discussed.     

Oestrous females investigate the unfamiliar male more than the familiar male in both commensal and non-commensal populations of house mice

We studied female preferences for familiar and unfamiliar males. The subjects were laboratory-born house mice: (1) non-commensal Mus musculus domesticus from the eastern part of Syria along the Euphrates River; and (2) commensal M. m. musculus from the Czech Republic. Pair-choice preference tests have revealed that oestrous females of both populations sniffed towards unfamiliar males more than familiar males. In the case of females exhibiting postpartum oestrus, this preference was less pronounced and statistically not significant. Thus, our mice clearly exhibited the behavioural pattern known from commensal populations of polygynous and/or promiscuous M. m. domesticus. We found no inverse tendency to seek proximity to the familiar male that has been previously reported from closely related and presumably monogamous aboriginal mouse Mus spicilegus. We conclude that neither commensal M. m. musculus, nor non-commensal M. m. domesticus, are likely to share a monogamous mating system with mound-building mice.     

Change of the Protein p53 Electrochemical Signal According to its Structural Form – Quick and Sensitive Distinguishing of Native, Denatured, and Aggregated Form of the “Guardian of the Genome”

Presence of mutated and/or structurally modified (e.g., denatured, aggregated) protein p53 form is associated with several disorders such as Alzheimer’s disease, Parkinson’s disease, prion diseases, and many types of tumours. The aim of this work was to distinguish native, denatured and aggregated form of full-length p53 by flow injection analysis coupled with electrochemical detector (FIA-ED). Firstly FIA-ED method used for protein native form determination was optimized (detection limit 45.8 amol per 5 μl injection; 3×S/N). In addition the technique was applied to identify p53 structural forms (denatured and aggregated). It was found out that denatured form provides about three times higher electrochemical response (protein structure unfolding, approach of more electroactive centers – aminoacid residues – towards electrode surface) in comparison with native form. On the other hand, aggregated form offers lower response (steric eclipse of electroactive protein parts) when compared with the signal of native form. The obtained data show that we are not only able to sensitively determine native, denatured, and aggregated structural forms of p53 protein but also to distinguish them.     

Distribution of PER protein,pigment-dispersing hormone,prothoracicotropic hormone,and eclosion hormone in the cephalic nervous system of insects

Investigations performed on adult insects revealed that putative components of the central pacemaker, the protein Period (PER) and the pigment-dispersing hormone (PDH), are immunocytochemically detectable in discrete sets of brain neurons throughout the class of Insecta, represented by a bristletail, mayfly, damselfly, 2 locust species, stonefly, 2 bug species, goldsmith beetle, caddisfly, honeybee, and 2 blowfly species. The PER-positive cells are localized in the frontal protocerebrum and in most species also in the optic lobes, which are their only location in damselfly and goldsmith beetle. Additional PER-positive cells occur in a few species either in the deuto- and tritocerebrum or in the suboesophageal ganglion. The PER staining was always confined to the cytoplasm. The PDH immunoreactivity consistently occurs in a cluster of perikarya located frontoventrally at the proximal edge of the medulla. The mayfly and both locust species possess additional PDH neurons in 2 posterior cell clusters at the proximal edge of the medulla, and mayfly, waterstrider, and 1 of the blowfly species in the central brain. PDH-positive fibers form a fanlike arrangement over the frontal side of the medulla. Two or just 1 bundle of PDH-positive fibers run from the optic lobe to the protocerebrum, with collaterals passing over to the contralateral optic lobe. Antisera to the prothoracicotropic (PTTH) and the eclosion (EH) hormones, which in some insects regulate the molting and ecdysis rhythms, respectively, typically react with a few neurons in the frontal protocerebrum. However, the PTTH-positive neurons of the mayfly and the damselfly and the EH-positive neurons of the caddisfly are located in the suboesophageal ganglion. No PTTH-like antigen was detected in locusts, and no EH-like antigens were detected in the damselfly, stonefly, locusts, and the honeybee. There are no signs of co-localization of the PER-, PDH-, PTTH-, and EH-like antigens in identical neurons.