CP250, a Novel Acidic Coiled Coil Protein of the Dictyostelium centrosome,Affects Growth,Chemotaxis, and the Nuclear Envelope

The Dictyostelium centrosome is a nucleus associated body consisting of a box-shaped core surrounded by the corona, an amorphous matrix functionally equivalent to the pericentriolar material of animal centrosomes which is responsible for the nucleation and anchoring of microtubules. Here we describe CP250 a component of the corona, an acidic coiled coil protein that is present at the centrosome throughout interphase while disappearing during prophase and reappearing at the end of late telophase. Amino acids 756-1148 of the 2110 amino acids are sufficient for centrosomal targeting and cell cycle–dependent centrosome association. Mutant cells lacking CP250 are smaller in size, growth on bacteria is delayed, chemotaxis is altered, and development is affected, which, in general, are defects observed in cytoskeletal mutants. Furthermore, loss of CP250 affected the nuclear envelope and led to reduced amounts and altered distribution of Sun-1, a conserved nuclear envelope protein that connects the centrosome to chromatin.     

Analysis of the Solvent Accessibility of Cysteine Residues on Maize rayado fino virus Virus-like Particles Produced in Nicotiana benthamiana Plants and Cross-linking of Peptides to VLPs

Mimicking and exploiting virus properties and physicochemical and physical characteristics holds promise to provide solutions to some of the world''s most pressing challenges. The sheer range and types of viruses coupled with their intriguing properties potentially give endless opportunities for applications in virus-based technologies. Viruses have the ability to self- assemble into particles with discrete shape and size, specificity of symmetry, polyvalence, and stable properties under a wide range of temperature and pH conditions. Not surprisingly, with such a remarkable range of properties, viruses are proposed for use in biomaterials ⁹, vaccines ^{14, 15}, electronic materials, chemical tools, and molecular electronic containers^{4, 5, 10, 11, 16, 18, 12}.In order to utilize viruses in nanotechnology, they must be modified from their natural forms to impart new functions. This challenging process can be performed through several mechanisms including genetic modification of the viral genome and chemically attaching foreign or desired molecules to the virus particle reactive groups ⁸. The ability to modify a virus primarily depends upon the physiochemical and physical properties of the virus. In addition, the genetic or physiochemical modifications need to be performed without adversely affecting the virus native structure and virus function. Maize rayado fino virus (MRFV) coat proteins self-assemble in Escherichia coli producing stable and empty VLPs that are stabilized by protein-protein interactions and that can be used in virus-based technologies applications ⁸. VLPs produced in tobacco plants were examined as a scaffold on which a variety of peptides can be covalently displayed ¹³. Here, we describe the steps to 1) determine which of the solvent-accessible cysteines in a virus capsid are available for modification, and 2) bioconjugate peptides to the modified capsids. By using native or mutationally-inserted amino acid residues and standard coupling technologies, a wide variety of materials have been displayed on the surface of plant viruses such as, Brome mosaic virus ³, Carnation mottle virus ¹², Cowpea chlorotic mottle virus ⁶, Tobacco mosaic virus ¹⁷, Turnip yellow mosaic virus ¹, and MRFV ¹³.     

T cell Ig and mucin domain-1-mediated T cell activation requires recruitment and activation of phosphoinositide 3-kinase

Ligation of the transmembrane protein T cell Ig and mucin domain (Tim)-1 can costimulate T cell activation. Agonistic Abs to Tim-1 are also capable of inducing T cell activation without additional stimuli. However, little is known about the biochemical mechanisms underlying T cell stimulation or costimulation through Tim-1. We show that a tyrosine in Tim-1 becomes phosphorylated in a lck-dependent manner, whereupon it can directly recruit p85 adaptor subunits of PI3K. This results in PI3K activation, which is required for Tim-1 function. We also provide genetic evidence that p85 expression is required for optimal Tim-1 function. Thus, we describe a pathway from Tim-1 tyrosine phosphorylation to the PI3K signaling pathway, which appears to be a major effector of Tim-1-mediated T cell activation.     

ICOS/ICOSL interaction is required for CD4+ invariant NKT cell function and homeostatic survival

The development of airway hyperreactivity (AHR), a cardinal feature of asthma, requires the presence of invariant NKT (iNKT) cells. In a mouse model of asthma, we demonstrated that the induction of AHR required ICOS costimulation of iNKT cells. ICOS was highly expressed on both naive and activated iNKT cells, and expression of ICOS was greater on the CD4(+) iNKT than on CD4(-) iNKT cells. Furthermore, the number of CD4(+) iNKT cells was significantly lower in spleens and livers of ICOS(-/-) and ICOSL(-/-) mice, and the remaining iNKT cells in ICOS(-/-) mice were dysfunctional and failed to reconstitute AHR when adoptively transferred into iNKT cell-deficient Jalpha18(-/-) mice. In addition, direct activation of iNKT cells with alpha-GalCer, which induced AHR in wild-type mice, failed to induce AHR in ICOS(-/-) mice. The failure of ICOS(-/-) iNKT cells to induce AHR was due in part to an inability of the ICOS(-/-) iNKT cells to produce IL-4 and IL-13 on activation. Moreover, survival of wild-type iNKT cells transferred into ICOSL(-/-) mice was greatly reduced due to the induction of apoptosis. These results indicate that ICOS costimulation plays a major role in induction of AHR by iNKT cells and is required for CD4(+) iNKT cell function, homeostasis, and survival in the periphery.     

Submitting articles to the BMJ

ObjectiveTo investigate how doctors engage with patients with psychotic illness in routine consultations.DesignConversation analysis of 32 consultations between psychiatrists and patients with schizophrenia or schizoaffective disorder.SettingTwo psychiatric outpatient clinics in east London and south west London.Participants7 psychiatrists and 32 patients with schizophrenia or schizoaffective disorder.ResultsPatients actively attempted to talk about the content of their psychotic symptoms in consultations by asking direct questions, repeating their questions and utterances, and producing these utterances in the concluding part of the consultation. In response, doctors hesitated, responded with a question rather than with an answer, and smiled or laughed (when informal carers were present), indicating that they were reluctant to engage with patients'' concerns about their psychotic symptoms.ConclusionsPatients repeatedly attempted to talk about the content of their psychotic symptoms, which was a source of noticeable interactional tension and difficulty. Addressing patients'' concerns about their illness may lead to a more satisfactory outcome of the consultation and improve engagement of such patients in the health services.

What is already known on this topic

Patients with psychotic illness are difficult to engage in the health servicesNo research has been published on how doctors engage with these patients in consultations

What this study adds

Patients actively attempt to talk about the content of their psychotic symptomsDoctors'' reluctance and discomfort in engaging with this topic is apparentAddressing patients'' concerns may lead to a more satisfactory outcome of the consultation and improve engagement with services     

Epidermal Growth Factor Receptor Inhibition Modulates the Microenvironment by Vascular Normalization to Improve Chemotherapy and Radiotherapy Efficacy

Background

Epidermal growth factor receptor (EGFR) inhibitors have shown only modest clinical activity when used as single agents to treat cancers. They decrease tumor cell expression of hypoxia-inducible factor 1-α (HIF-1α) and vascular endothelial growth factor (VEGF). Hypothesizing that this might normalize tumor vasculature, we examined the effects of the EGFR inhibitor erlotinib on tumor vascular function, tumor microenvironment (TME) and chemotherapy and radiotherapy sensitivity.

Methodology/Principal Findings

Erlotinib treatment of human tumor cells in vitro and mice bearing xenografts in vivo led to decreased HIF-1α and VEGF expression. Treatment altered xenograft vessel morphology assessed by confocal microscopy (following tomato lectin injection) and decreased vessel permeability (measured by Evan''s blue extravasation), suggesting vascular normalization. Erlotinib increased tumor blood flow measured by Power Doppler ultrasound and decreased hypoxia measured by EF5 immunohistochemistry and tumor O₂ saturation measured by optical spectroscopy. Predicting that these changes would improve drug delivery and increase response to chemotherapy and radiation, we performed tumor regrowth studies in nude mice with xenografts treated with erlotinib and either radiotherapy or the chemotherapeutic agent cisplatin. Erlotinib therapy followed by cisplatin led to synergistic inhibition of tumor growth compared with either treatment by itself (p<0.001). Treatment with erlotinib before cisplatin led to greater tumor growth inhibition than did treatment with cisplatin before erlotinib (p = 0.006). Erlotinib followed by radiation inhibited tumor regrowth to a greater degree than did radiation alone, although the interaction between erlotinib and radiation was not synergistic.

Conclusions/Significance

EGFR inhibitors have shown clinical benefit when used in combination with conventional cytotoxic therapy. Our studies show that targeting tumor cells with EGFR inhibitors may modulate the TME via vascular normalization to increase response to chemotherapy and radiotherapy. These studies suggest ways to assess the response of tumors to EGFR inhibition using non-invasive imaging of the TME.     

Geographic and stratigraphic distributions of the Caribbean species of Cladocora (Scleractinia, Faviidae)

A complete account of the faviid genus Cladocora within the Caribbean is presented. In the Caribbean this genus represents an extant group that had its earliest occurrence during the Campanian-Maastrichtian of Jamaica. Recent forms have been reported throughout the Caribbean. The following forms were found (with stratigraphic ranges in the Caribbean): C. arbuscula (Pliocene-Recent), C. debilis (Pleistocene-Recent), C. gracilis (Middle-Upper Maastrichtian), C. jamaicaensis (Campanian-Maastrichtian and Eocene), C. johnsoni (Pliocene), and C. recrescens (Middle-Upper Oligocene). The occurrence of the genus Cladocora in the Caribbean is largely continuous from the Campanian to Recent, during the majority of the Caribbean species show affinities to European assemblages. For the time intervals Paleocene, Lower Oligocene, and Miocene the taxon has not been reported from the Caribbean.