Cytokine-related genes identified from the RIKEN full-length mouse cDNA data set

To identify novel cytokine-related genes, we searched the set of 60,770 annotated RIKEN mouse cDNA clones (FANTOM2 clones), using keywords such as cytokine itself or cytokine names (such as interferon, interleukin, epidermal growth factor, fibroblast growth factor, and transforming growth factor). This search produced 108 known cytokines and cytokine-related products such as cytokine receptors, cytokine-associated genes, or their products (enhancers, accessory proteins, cytokine-induced genes). We found 15 clusters of FANTOM2 clones that are candidates for novel cytokine-related genes. These encoded products with strong sequence similarity to guanylate-binding protein (GBP-5), interleukin-1 receptor-associated kinase 2 (IRAK-2), interleukin 20 receptor alpha isoform 3, a member of the interferon-inducible proteins of the Ifi 200 cluster, four members of the membrane-associated family 1-8 of interferon-inducible proteins, one p27-like protein, and a hypothetical protein containing a Toll/Interleukin receptor domain. All four clones representing novel candidates of gene products from the family contain a novel highly conserved cross-species domain. Clones similar to growth factor-related products included transforming growth factor beta-inducible early growth response protein 2 (TIEG-2), TGFbeta-induced factor 2, integrin beta-like 1, latent TGF-binding protein 4S, and FGF receptor 4B. We performed a detailed sequence analysis of the candidate novel genes to elucidate their likely functional properties.

Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease

Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.

Phonological sensitivity as a proximal contributor to phonological recoding skills in children's reading

Because it permits self-teaching, phonological recoding (the efficient translation of letters or letter groups into sound) is arguably the key skill acquired in learning to read an alphabetic writing system. Deficits in this skill are the most common source of children's reading difficulties. In addition, poor readers tend to perform at a lower level than good readers on a wide variety of phonological processing tasks. These findings have been widely interpreted as implying a latent phonological processing ability as a distal cause of variation in reading skill. Clearly, such an interpretation does not imply that all phonological processing skills contribute directly to the phonological recoding process. This paper outlines a series of studies conducted at the University of Queensland. This work consistently suggests that children's phonological sensitivity contributes more directly than other phonological processing abilities to the development of phonological recoding skills.

Patch dynamics and metapopulation theory: the case of successional species

We present a mathematical framework that combines extinction-colonization dynamics with the dynamics of patch succession. We draw an analogy between the epidemiological categorization of individuals (infected, susceptible, latent and resistant) and the patch structure of a spatially heterogeneous landscape (occupied-suitable, empty-suitable, occupied-unsuitable and empty-unsuitable). This approach allows one to consider life-history attributes that influence persistence in patchy environments (e.g., longevity, colonization ability) in concert with extrinsic processes (e.g., disturbances, succession) that lead to spatial heterogeneity in patch suitability. It also allows the incorporation of seed banks and other dormant life forms, thus broadening patch occupancy dynamics to include sink habitats. We use the model to investigate how equilibrium patch occupancy is influenced by four critical parameters: colonization rate? extinction rate, disturbance frequency and the rate of habitat succession. This analysis leads to general predictions about how the temporal scaling of patch succession and extinction-colonization dynamics influences long-term persistence. We apply the model to herbaceous, early-successional species that inhabit open patches created by periodic disturbances. We predict the minimum disturbance frequency required far viable management of such species in the Florida scrub ecosystem. (C) 2001 Academic Press.

The genetic and environmental relationship between the interpersonal sensitivity measure (IPSM) and the personality dimensions of Eysenck and Cloninger

A shortened version of the Interpersonal Sensitivity Measure (IPSM) developed to predict depression prone personalities was administered in a self-report questionnaire to a community-based sample of 3269 Australian twin pairs aged 18-28 years, along with Eysenck's EPQ and Cloninger's TPQ. The IPSM included four sub-scales: Separation Anxiety (SEP); Interpersonal Sensitivity (INT); Fragile Inner-Self (FIS); and Timidity (TIM). Univariate analysis revealed that individual differences in the IPSM sub-scale scores were best explained by additive genetic and specific environmental effects. Confirming previous research findings, familial aggregation for the EPQ and TPQ personality dimensions was entirely due to additive genetic effects. In the multivariate case, a model comprising additive genetic and specific environmental effects best explained the covariation between the latent factors for male and female twin pairs alike. The EPQ and TPQ dimensions accounted for moderate to large proportions of the genetic variance (40-76%) in the IPSM sub-scales, while most of the non-shared environment variance was unique to the IPSM sub-scales. (C) 2001 Elsevier Science Ltd. All rights reserved.

Contrasting Epstein-Barr virus-specific cytotoxic T cell responses to HLA A2-restricted epitopes in humans and HLA transgenic mice: implications for vaccine design

This study investigates the hierarchy of cytotoxic T cell (CTL) responses to twelve HLA A2-restricted epitopes from the latent, lytic and structural proteins of Epstein–Barr virus (EBV) in acute infectious mononucleosis and in healthy seropositive donors and the relative immunogenecity of these epitopes in transgenic mice. Responses to the lytic epitope were uniformly strong in all healthy seropositive individuals and acute infectious mononucleosis donors while moderate or low responses were observed to the latent and structural epitopes, respectively in both groups studied. In contrast, when HLA A2/Kb transgenic mice were immunised with these peptide epitopes, CTL responses were observed to all epitopes with a maximal response to the epitopes within the structural proteins and low to moderate responses to the latent epitopes. This hierarchy of CTL responses in mice was also reflected in an MHC stabilisation analysis. These contrasting CTL responses in humans following natural infection compared to the immunogenicity of these epitopes and their ability to stabilise MHC may need to be considered when designing an EBV vaccine.

The immunology of Epstein-Barr virus infection

Epstein-Barr virus is a classic example of a persistent human virus that has caught the imagination of immunologists, virologists and oncologists because of the juxtaposition of a number of important properties. First, the ability of the virus to immortalize B lymphocytes in vitro has provided an antigen presenting cell in which all the latent antigens: of the virus are displayed and are available for systematic study. Second, the virus presents an ideal system for studying the immune parameters that maintain latency and the consequences of disturbing this cell-virus relationship. Third, this wealth of immunological background has provided a platform for elucidating the role of the immune system in protection from viral-associated malignancies of B cell and epithelial cell origin. Finally attention is now being directed towards the development of vaccine formulations which might have broad application in the control of human malignancies.

Role of LMP1 in immune control of EBV infection

The Epstein-Barr virus (EBV) encoded latent membrane protein (LMP1) plays a crucial role in the long-term persistence of this virus within the cells of the immune system. Not only is this protein critical for the transformation of resting B cells by EBV, it also displays pleiotropic effects on various cellular proteins expressed in the host cell. These include up-regulation of expression of B cell activation antigens, adhesion molecules and various components of the antigen processing pathway. Here we discuss how LMP1 acts like an expression 'switch' which, depending on the stage of EBV infection, manoeuvres various pathways that either modulate the immune system towards or against its survival.

Pyramidal neurones in macaque visual cortex: Interareal phenotypic variation of dendritic branching patterns

The basal dendritic arbors of over 500-layer III pyramidal neurones of the macaque cortex were compared by fractal analyses, which provides a measure of the space filling (or branching pattern) of dendritic arbors. Fractal values (D) of individual cells were compared between the cytochrome oxidase (CO)-rich blobs and CO-poor interblobs, of middle and upper layer III, and between sublaminae, in the primary visual area (Vi). These data were compared with those in the CO compartments in the second visual area (V2), and seven other extrastriate cortical areas. (V4, MT, LIP, 7a, TEO, TE and STP). There were significant differences in the fractal dimensions, and therefore the dendritic branching patterns, of cells in striate and extrastriate areas. Of the 55 possible pairwise comparisons of fractal dimension of neurones in different cortical areas (or CO compartments), 39 proved to be significantly different. The markedly different morphologies of pyramidal cells in the different cortical areas may be one of the features that determine the functional signatures of these cells by influencing the number of inputs received by, and propagation of potentials through, their dendritic arbors.

Clinically significant drug interactions with agents specific for migraine attacks

The drugs which provide specific relief from migraine attacks, the ergopeptides (ergotamine and dihydroergotamine) and the various 'triptans' (notably sumatriptan), are often prescribed for persons already taking various migraine preventative agents, and sometimes drugs for other indications. As a result, migraine-specific drugs may become involved in drug-drug interactions. The migraine-specific drugs all act as agonists at certain subclasses of serotonin (5-hydroxytryptamine; 5-MT) receptor, particularly those of the 5-HT1D subtype, and produce vasoconstriction through these receptor-mediated mechanisms. The oral bioavailabilities of these drugs, particularly those of the ergopeptides, are often incomplete, due to extensive presystemic metabolism. As a result, if migraine-specific agents are coadministered with drugs with vasoconstrictive properties, or with drugs which inhibit the metabolism of the migraine-specific agents, there is a risk of interactions occurring which produce manifestations of excessive vasoconstriction. This can also occur through pharmacodynamic mechanisms, as when ergopeptides or triptans are coadministered with methysergide or propranolol (although a pharmacokinetic element may apply in relation to the latter interaction), or if one migraine-specific agent is used shortly after another. When egopeptide metabolism is inhibited by the presence of macrolide antibacterials, particularly troleandomycin and erythromycin, the resultant interaction can produce ergotism, sometimes leading to gangrene. Similar pharmacokinetic mechanisms, with their vasoconstrictive consequences, probably apply to combination of the ergopeptides with HIV protease inhibitors (indinavir and ritonavir), heparin, cyclosporin or tacrolimus. Inhibition of triptan metabolism by monoamine oxidase A inhibitors, e.g. moclobemide, may raise circulating triptan concentrations, although this does not yet seem to have led to reported clinical problems. Caffeine may cause increased plasma ergotamine concentrations through an as yet inadequately defined pharmacokinetic interaction. However, a direct antimigraine effect of caffeine may contribute to the claimed increased efficacy of ergotamine-caffeine combinations in relieving migraine attacks. Serotonin syndromes have been reported as probable pharmacodynamic consequences of the use of ergots or triptans in persons taking serotonin reuptake inhibitors. There have been two reports of involuntary movement disorders when sumatriptan has been used by patients already taking loxapine. Nearly all the clinically important interactions between the ergopeptide antimigraine agents and currently marketed drugs are likely to have already come to notice. In contrast, new interactions involving the triptans are likely to be recognised as additional members of this family of drugs, with their different patterns of metabolism and pharmacokinetics, are marketed.

Nonword repetition and young children's receptive vocabulary: A longitudinal study

A longitudinal study investigated the claim that phonological memory contributes to vocabulary acquisition in young children. In the first phase, children were given tests of receptive vocabulary, receptive grammar, nonword repetition, phonological sensitivity (or awareness), and performance IQ. In the second phase, children were given the nonword repetition and receptive vocabulary tests. In Session 1, both nonword repetition and phonological sensitivity accounted for variation in receptive vocabulary and grammar after performance IQ effects were controlled. When phonological sensitivity was also controlled, nonword repetition did not account for significant additional variation in receptive vocabulary and grammar, When performance IQ and autoregression effects were controlled, all Session I verbal ability measures predicted Session 2 vocabulary, but only Session 1 vocabulary predicted Session 2 nonword repetition. When phonological sensitivity was also controlled. Session 1 nonword repetition (leniently scored) predicted Session 2 vocabulary. Overall, these findings show qualified support for the claim that the capacity component of nonword repetition contributes directly to vocabulary in young children. They suggest that the association between nonword repetition and vocabulary in young children may, to a substantial extent, reflect a latent phonological processing ability that is also manifest in phonological sensitivity.

Stable expression of noncytopathic Kunjin replicons simulates both ultrastructural and biochemical characteristics observed during replication of Kunjin virus

This report focuses mainly on the characterization of a Vero cell line stably expressing the flavivirus Kunjin (KUN) replicon C20SDrep (C20SDrepVero). We showed by immunofluorescence and cryoimmunoelectron microscopy that unique flavivirus-induced membrane structures, termed convoluted membranes/paracrystalline structures, were induced in the C20SDrepVero cells. These induced cytoplasmic foci were immunolabeled with KUN virus anti-NS3 antibodies and with antibodies to the cellular markers ERGIC53 (for the intermediate compartment) and protein disulfide isomerase (for the rough endoplasmic reticulum). However, in contrast to the large perinuclear inclusions observed by immunofluorescence with anti-double-stranded (ds)RNA antibodies in KUN virus-infected cells, the dsRNA in C20SDrepVero cells was localized to small isolated foci scattered throughout the cytoplasm, which were coincident with small foci dual-labeled with the trans-Golgi specific marker GaIT. importantly persistent expression of the KUN replicons in cells did not produce cytopathic effects, and the morphology of major host organelles (including Golgi, mitochondria, endoplasmic reticulum, and nucleus) was apparently unaffected. The amounts of plus- and minus-sense RNA synthesis in replicon cells were similar to those in KUN virus-infected cells until near the end of the latent period, but subsequently increases of about 10- and fourfold, respectively, occurred in infected cells. Virus-specified protein synthesis in C20SDrepVero cells was also about 10-fold greater than that in infected cells. When several KUN replicon cell lines were compared with respect to membrane induction, the relative efficiencies increased in parallel with increases in viral RNA and protein synthesis, consistent with the increases observed during the virus infectious cycle. Based on these observations, cell lines expressing less-efficient replicons may provide a useful tool to study early events in flavivirus RNA replication, which are difficult to assess in Virus infections. (C) 2001 Academic press.

A total-evidence phylogeny of ticks provides insights into the evolution of life cycles and biogeography

We inferred the phylogeny of 33 species of ticks from the subfamilies Rhipicephalinae and Hyalomminae from analyses of nuclear and mitochondrial DNA and morphology. We used nucleotide sequences from 12S rRNA, cytochrome c oxidase I, internal transcribed spacer 2 of the nuclear rRNA, and 18S rRNA. Nucleotide sequences and morphology were analyzed separately and together in a total-evidence analysis. Analyses of the five partitions together (3303 characters) gave the best-resolved and the best-supported hypothesis so far for the phylogeny of ticks in the Rhipicephalinae and Hyalomminae, despite the fact that some partitions did not have data for some taxa. However, most of the hidden conflict (lower support in the total-evidence analyses compared to that in the individual analyses) was found in those partitions that had taxa without data. The partitions with complete taxonomic sampling had more hidden support (higher support in the total-evidence analyses compared to that in the separate-partition analyses) than hidden conflict. Mapping of geographic origins of ticks onto our phylogeny indicates an African origin for the Rhipicephalinae sensu lato (i.e., including Hyalomma spp.), the Rhipicephalus-Boophilus lineage, the Dermacentor-Anocentor lineage, and the Rhipicephalus-Booophilus-Nosomma-Hyalomma-Rhipicentor lineage. The Nosomma-Hyalomma lineage appears to have evolved in Asia. Our total-evidence phylogeny indicates that (i) the genus Rhipicephalus is paraphyletic with respect to the genus Boophilus, (ii) the genus Dermacentor is paraphyletic with respect to the genus Anocentor, and (iii) some subgenera of the genera Hyalomma and Rhipicephalus are paraphyletic with respect to other subgenera in these genera. Study of the Rhipicephalinae and Hyalomminae over the last 7 years has shown that analyses of individual datasets (e.g., one gene or morphology) seldom resolve many phylogenetic relationships, but analyses of more than one dataset can generate well-resolved phylogenies for these ticks. (C) 2001 Academic Press.

Delayed emergence of bovine leukemia virus after vaccination with a protective cytotoxic T cell-based vaccine

In a previous study eight MHC class I-matched sheep were vaccinated with a minimal cytotoxic T lymphocyte (CTL) peptide epitope vaccine and were challenged with the retrovirus, bovine leukemia virus (BLV). Half the vaccinated animals remained PCR negative after challenge, whereas the remaining half and the placebo group became PCR positive within 4 weeks postchallenge (Hislop AD, Good MF, Mateo L, Gardner J, Gatei MH, Daniel RCW, Meyers BV, Lavin MF, and Suhrbier A: Nat Med 1998; 4: 1193). Here we show that neither epitope mutations nor processing differences explained why half the peptide-vaccinated animals failed to resist the BLV challenge. However, in these animals the development of BLV-induced lymphosarcomas was significantly delayed compared with the placebo group, suggesting a role for CTLs in preventing retrovirus-induced cancers. Importantly, two of the initially protected animals become PCR positive after similar to1.5 years, indicating extended suppression but not elimination of challenge virus by vaccine-induced CTLs. The late emergence of virus could not be explained by epitope escape mutations or the loss of memory CTL responses. We speculate that high levels of effector CTL may be needed to protect animals from a postchallenge viremia and maintenance of such effector CTLs, rather than memory CTLs, may be required to prevent subsequent emergence of virus from latent pools.

A histone deacetylase inhibitor, azelaic bishydroxamic acid, shows cytotoxicity on Epstein-Barr virus-transformed B-cell lines - A potential therapy for posttransplant lymphoproliferative disease

Background. Posttransplant lymphoproliferative disease (PTLD), driven by the presence of Epstein-Barr virus (EBV), is becoming an increasingly important clinical problem after solid organ transplantation. The use of immunosuppressive therapy leads to the inhibition of the cytotoxic T cells that normally control the EBV latently infected B cells. The prognosis for many patients with PTLD is poor, and the optimal treatment strategy is not well defined. Method. This study investigates the use of a histone deacetylase inhibitor, azelaic bishydroxamic acid (ABRA), for its ability to effectively kill EBV-transformed lymphoblastoid cell lines. Results. In vitro treatment of lymphoblastoid cell lines with ABRA showed that they were effectively killed by low doses of the drug (ID50 2-5 mug/ml) within 48 hr. As well as being effective against polyclonal B-cell lines, ABHA was also shown to be toxic to seven of eight clonal Burkitt's lymphoma cell lines, indicating that the drug may also be useful in the treatment of late-occurring clonal PTLD. In addition, ABHA treatment did not induce EBV replication or affect EBV latent gene expression. Conclusion. These studies suggest that ABHA effectively kills both polyclonal and clonal B-cell lines and has potential in the treatment of PTLD.