Two novel human cytomegalovirus NK cell evasion functions target MICA for lysosomal degradation

NKG2D plays a major role in controlling immune responses through the regulation of natural killer (NK) cells, αβ and γδ T-cell function. This activating receptor recognizes eight distinct ligands (the MHC Class I polypeptide-related sequences (MIC) A andB, and UL16-binding proteins (ULBP)1–6) induced by cellular stress to promote recognition cells perturbed by malignant transformation or microbial infection. Studies into human cytomegalovirus (HCMV) have aided both the identification and characterization of NKG2D ligands (NKG2DLs). HCMV immediate early (IE) gene up regulates NKGDLs, and we now describe the differential activation of ULBP2 and MICA/B by IE1 and IE2 respectively. Despite activation by IE functions, HCMV effectively suppressed cell surface expression of NKGDLs through both the early and late phases of infection. The immune evasion functions UL16, UL142, and microRNA(miR)-UL112 are known to target NKG2DLs. While infection with a UL16 deletion mutant caused the expected increase in MICB and ULBP2 cell surface expression, deletion of UL142 did not have a similar impact on its target, MICA. We therefore performed a systematic screen of the viral genome to search of addition functions that targeted MICA. US18 and US20 were identified as novel NK cell evasion functions capable of acting independently to promote MICA degradation by lysosomal degradation. The most dramatic effect on MICA expression was achieved when US18 and US20 acted in concert. US18 and US20 are the first members of the US12 gene family to have been assigned a function. The US12 family has 10 members encoded sequentially through US12–US21; a genetic arrangement, which is suggestive of an ‘accordion’ expansion of an ancestral gene in response to a selective pressure. This expansion must have be an ancient event as the whole family is conserved across simian cytomegaloviruses from old world monkeys. The evolutionary benefit bestowed by the combinatorial effect of US18 and US20 on MICA may have contributed to sustaining the US12 gene family

Solution structure of a repeated unit of the ABA-1 nematode polyprotein allergen of ascaris reveals a novel fold and two discrete lipid-binding sites

Parasitic nematode worms cause serious health problems in humans and other animals. They can induce allergic-type immune responses, which can be harmful but may at the same time protect against the infections. Allergens are proteins that trigger allergic reactions and these parasites produce a type that is confined to nematodes, the nematode polyprotein allergens (NPAs). These are synthesized as large precursor proteins comprising repeating units of similar amino acid sequence that are subsequently cleaved into multiple copies of the allergen protein. NPAs bind small lipids such as fatty acids and retinol (Vitamin A) and probably transport these sensitive and insoluble compounds between the tissues of the worms. Nematodes cannot synthesize these lipids, so NPAs may also be crucial for extracting nutrients from their hosts. They may also be involved in altering immune responses by controlling the lipids by which the immune and inflammatory cells communicate. We describe the molecular structure of one unit of an NPA, the well-known ABA-1 allergen of Ascaris and find its structure to be of a type not previously found for lipid-binding proteins, and we describe the unusual sites where lipids bind within this structur

The Human Herpesvirus-7 (HHV-7) U21 Immunoevasin Subverts NK-Mediated Cytoxicity through Modulation of MICA and MICB

Herpesviruses have evolved numerous immune evasion strategies to facilitate establishment of lifelong persistent infections. Many herpesviruses encode gene products devoted to preventing viral antigen presentation as a means of escaping detection by cytotoxic T lymphocytes. The human herpesvirus-7 (HHV-7) U21 gene product, for example, is an immunoevasin that binds to class I major histocompatibility complex molecules and redirects them to the lysosomal compartment. Virus infection can also induce the upregulation of surface ligands that activate NK cells. Accordingly, the herpesviruses have evolved a diverse array of mechanisms to prevent NK cell engagement of NK-activating ligands on virus-infected cells. Here we demonstrate that the HHV-7 U21 gene product interferes with NK recognition. U21 can bind to the NK activating ligand ULBP1 and reroute it to the lysosomal compartment. In addition, U21 downregulates the surface expression of the NK activating ligands MICA and MICB, resulting in a reduction in NK-mediated cytotoxicity. These results suggest that this single viral protein may interfere both with CTL-mediated recognition through the downregulation of class I MHC molecules as well as NK-mediated recognition through downregulation of NK activating ligands

CLINICAL EVALUATION OF A MOBILE PHONE TELEMEDICINE SYSTEM FOR THE SELF-MANAGEMENT OF TYPE 1 DIABETES

Abstract – A mobile phone system for the selfmanagement of Type 1 diabetes was tested in a clinical randomized controlled trial. Both intervention and control groups used the system, but the intervention group had extra feedback and proactive nurse support. Both groups showed improvements in blood glucose control, as measured by HbA1c, although the difference in HbA1c change between groups was not statistically significant. The difference in compliance between groups was highly significant, however, showing the importance of targeted support from healthcare professionals in the use of such systems. I

Sexual counselling for patients with cardiovascular disease: protocol for a pilot study of the CHARMS sexual counselling intervention.

Introduction Sexual problems are common with cardiovascular disease, and can negatively impact quality of life. To address sexual problems, guidelines have identified the importance of sexual counselling during cardiac rehabilitation, yet this is rarely provided. The Cardiac Health and Relationship Management and Sexuality (CHARMS) intervention aims to improve the provision of sexual counselling in cardiac rehabilitation in Ireland.Methods and analysis This is a multicentre pilot study for the CHARMS intervention, a complex, multilevel intervention delivered within hospital-based cardiac rehabilitation programmes. The intervention includes (1) training in sexual counselling for staff, (2) a staff-led patient education and support intervention embedded within the cardiac rehabilitation programme, (3) a patient information booklet and (4) an awareness raising poster. The intervention will be delivered in two randomly selected cardiac rehabilitation centres. In each centre 30 patients will be recruited, and partners will also be invited to participate. Data will be collected from staff and patients/partners at T1 (study entry), T2 (3-month follow-up) and T3 (6-month follow-up). The primary outcome for patients/partners will be scores on the Sexual Self-Perception and Adjustment Questionnaire. Secondary outcomes for patients/partners will include relationship satisfaction; satisfaction with and barriers to sexual counselling in services; sexual activity, functioning and knowledge; physical and psychological well-being. Secondary outcomes for staff will include sexuality-related practice; barriers to sexual counselling; self-ratings of capability, opportunity and motivation; sexual attitudes and beliefs; knowledge of cardiovascular disease and sex. Fidelity of intervention delivery will be assessed using trainer self-reports, researcher-coded audio recordings and exit interviews. Longitudinal feasibility data will be gathered from patients/partners and staff via questionnaires and interviews.Ethics and dissemination This study is approved by the Research Ethics Committee (REC) of the National University of Ireland, Galway. Findings will be disseminated to cardiac rehabilitation staff, patients/partners and relevant policymakers via appropriate publications and presentations.PUBLISHEDpeer-reviewe