The Ins and Outs of TAPBPR.

Peptide presentation on MHC class I molecules (MHC-I) is central to mounting effective antiviral and antitumoral immune responses. The tapasin-related protein TAPBPR is an MHC-I peptide editor which shapes the final peptide repertoire displayed on the cell surface. Here, we review recent findings which further elucidate the mechanisms by which TAPBPR performs peptide editing on a molecular level, and how glycosylation on MHC-I influences the interaction with TAPBPR and the peptide loading complex. We also explore how the function of TAPBPR can be utilized to promote exogenous peptide loading directly onto plasma-membrane expressed MHC-I. This has led to the development of new assays to investigate TAPBPR-mediated peptide editing and uncovered translational opportunities of utilizing TAPBPR to treat human disease.Wellcom

Increasing access to consumer health organisations among patients with chronic disease - a randomised trial of a print-based intervention

To assess whether a print-based intervention led to increased contact with consumer health organisations (CHOs) by general practice patients with chronic disease. CHOs can enhance people's capacity to manage chronic illness by providing information, education and psychosocial support. However, these organisations appear to be grossly under-utilised by patients and clinicians. A total of 276 patients completed a computer-assisted telephone interview before randomisation to an intervention (n = 141) or control (n = 135) group. The intervention consisted of mailed printed materials designed to encourage contact with a CHO relevant to the patient's main diagnosed chronic condition. Follow-up interviews were conducted 4 and 12 months later. Patients with conditions other than diabetes who received the intervention were twice as likely as those in the control group to contact a consumer health organisation during the 12-month study period: 41% versus 21% (P < 0.001). No such effect was found for diabetes patients, probably because of pre-existing high levels of contact with diabetes organisations. The intervention package received strong patient endorsement. Low-intensity interventions may be effective in improving access to CHOs for patients with chronic disease

TAPBPR mediates peptide dissociation from MHC class I using a leucine lever.

Tapasin and TAPBPR are known to perform peptide editing on major histocompatibility complex class I (MHC I) molecules; however, the precise molecular mechanism(s) involved in this process remain largely enigmatic. Here, using immunopeptidomics in combination with novel cell-based assays that assess TAPBPR-mediated peptide exchange, we reveal a critical role for the K22-D35 loop of TAPBPR in mediating peptide exchange on MHC I. We identify a specific leucine within this loop that enables TAPBPR to facilitate peptide dissociation from MHC I. Moreover, we delineate the molecular features of the MHC I F pocket required for TAPBPR to promote peptide dissociation in a loop-dependent manner. These data reveal that chaperone-mediated peptide editing on MHC I can occur by different mechanisms dependent on the C-terminal residue that the MHC I accommodates in its F pocket and provide novel insights that may inform the therapeutic potential of TAPBPR manipulation to increase tumour immunogenicity.Wellcome PhD studentship (109076/Z/15/A). Wellcome Senior Research Fellowship (104647/Z/14/Z) South African Medical Research Council Bosch-Forschungsstiftung. Royal Society University Research Fellowship (UF100371)

TAPBPR bridges UDP-glucose : glycoprotein glucosyltransferase 1 onto MHC class I to provide quality control in the antigen presentation pathway

Funding Wellcome: Senior Research Fellowship 104647, Andreas Neerincx, Louise H Boyle Royal Society: University Research Fellowship, UF100371, Janet E Deane Cancer Research UK: Programme Grant, C7056A, Andy van Hateren, Tim Elliott Deutsche Forschungsgemeinschaft: SFB 685, Nico Trautwein, Stefan Stevanović Wellcome: PhD studentship, 089563, Clemens Hermann Wellcome: Strategic Award 100140, Robin Antrobus Wellcome: Programme grant, WT094847MA, Huan Cao Acknowledgements We are extremely grateful to Peter Cresswell and Najla Arshad (Yale University School of Medicine, New Haven, CT) for valuable advice, tapasin and TAP-specific antibody reagents, and the recombinant calreticulin proteins. We thank John Trowsdale (University of Cambridge, UK) for his mentorship and critical reading of this manuscript, and Jim Kaufman (University of Cambridge, UK) for useful discussions. We also thank Yi Cao (Cranfield University, UK) for MATLAB programming for densitometry analysis, and Mark Vickers and Sadie Henderson (Scottish National Blood Transfusion Services, UK) for permitting the use of and assistance with the Amersham WB system. The reagent ARP7099 FEC peptide pool was obtained from the Centre for AIDS Reagents, National Institute for Biological Standards and Control (NIBSC), and was donated by the NIH AIDS Reagent Program, Division of AIDS, NIAID, NIH.Peer reviewedPublisher PD

Utilizing TAPBPR to promote exogenous peptide loading onto cell surface MHC I molecules.

The repertoire of peptides displayed at the cell surface by MHC I molecules is shaped by two intracellular peptide editors, tapasin and TAPBPR. While cell-free assays have proven extremely useful in identifying the function of both of these proteins, here we explored whether a more physiological system could be developed to assess TAPBPR-mediated peptide editing on MHC I. We reveal that membrane-associated TAPBPR targeted to the plasma membrane retains its ability to function as a peptide editor and efficiently catalyzes peptide exchange on surface-expressed MHC I molecules. Additionally, we show that soluble TAPBPR, consisting of the luminal domain alone, added to intact cells, also functions as an effective peptide editor on surface MHC I molecules. Thus, we have established two systems in which TAPBPR-mediated peptide exchange on MHC class I can be interrogated. Furthermore, we could use both plasma membrane-targeted and exogenous soluble TAPBPR to display immunogenic peptides on surface MHC I molecules and consequently induce T cell receptor engagement, IFN-γ secretion, and T cell-mediated killing of target cells. Thus, we have developed an efficient way to by-pass the natural antigen presentation pathway of cells and load immunogenic peptides of choice onto cells. Our findings highlight a potential therapeutic use for TAPBPR in increasing the immunogenicity of tumors in the future

Mental Disorder in Children with Physical Conditions: a Pilot Study

OBJECTIVES: Methodologically, to assess the feasibility of participant recruitment and retention, as well as missing data in studying mental disorder among children newly diagnosed with chronic physical conditions (ie, multimorbidity). Substantively, to examine the prevalence of multimorbidity, identify sociodemographic correlates and model the influence of multimorbidity on changes in child quality of life and parental psychosocial outcomes over a 6-month follow-up. DESIGN: Prospective pilot study. SETTING: Two children\u27s tertiary-care hospitals. PARTICIPANTS: Children aged 6-16 years diagnosed in the past 6 months with one of the following: asthma, diabetes, epilepsy, food allergy or juvenile arthritis, and their parents. OUTCOME MEASURES: Response, participation and retention rates. Child mental disorder using the Mini International Neuropsychiatric Interview at baseline and 6 months. Child quality of life, parental symptoms of stress, anxiety and depression, and family functioning. All outcomes were parent reported. RESULTS: Response, participation and retention rates were 90%, 83% and 88%, respectively. Of the 50 children enrolled in the study, the prevalence of multimorbidity was 58% at baseline and 42% at 6 months. No sociodemographic characteristics were associated with multimorbidity. Multimorbidity at baseline was associated with declines over 6 months in the following quality of life domains: physical well-being, β=-4.82 (-8.47, -1.17); psychological well-being, β=-4.10 (-7.62, -0.58) and school environment, β=-4.17 (-8.18, -0.16). There was no association with parental psychosocial outcomes over time. CONCLUSIONS: Preliminary evidence suggests that mental disorder in children with a physical condition is very common and has a negative impact on quality of life over time. Based on the strong response rate and minimal attrition, our approach to study child multimorbidity appears feasible and suggests that multimorbidity is an important concern for families. Methodological and substantive findings from this pilot study have been used to implement a larger, more definitive study of child multimorbidity, which should lead to important clinical implications

Cellular expression, trafficking, and function of two isoforms of human ULBP5/RAET1G

Background: The activating immunoreceptor NKG2D is expressed on Natural Killer (NK) cells and subsets of T cells. NKG2D contributes to anti-tumour and anti-viral immune responses in vitro and in vivo. The ligands for NKG2D in humans are diverse proteins of the MIC and ULBP/RAET families that are upregulated on the surface of virally infected cells and tumours. Two splicing variants of ULBP5/RAET1G have been cloned previously, but not extensively characterised. Methodology/Principal Findings: We pursue a number of approaches to characterise the expression, trafficking, and function of the two isoforms of ULBP5/RAET1G. We show that both transcripts are frequently expressed in cell lines derived from epithelial cancers, and in primary breast cancers. The full-length transcript, RAET1G1, is predicted to encode a molecule with transmembrane and cytoplasmic domains that are unique amongst NKG2D ligands. Using specific anti-RAET1G1 antiserum to stain tissue microarrays we show that RAET1G1 expression is highly restricted in normal tissues. RAET1G1 was expressed at a low level in normal gastrointestinal epithelial cells in a similar pattern to MICA. Both RAET1G1 and MICA showed increased expression in the gut of patients with celiac disease. In contrast to healthy tissues the RAET1G1 antiserum stained a wide variety or different primary tumour sections. Both endogenously expressed and transfected RAET1G1 was mainly found inside the cell, with a minority of the protein reaching the cell surface. Conversely the truncated splicing variant of RAET1G2 was shown to encode a soluble molecule that could be secreted from cells. Secreted RAET1G2 was shown to downregulate NKG2D receptor expression on NK cells and hence may represent a novel tumour immune evasion strategy. Conclusions/Significance: We demonstrate that the expression patterns of ULBP5RAET1G are very similar to the well-characterised NKG2D ligand, MICA. However the two isoforms of ULBP5/RAET1G have very different cellular localisations that are likely to reflect unique functionality

TAPBPR alters MHC class I peptide presentation by functioning as a peptide exchange catalyst.

Our understanding of the antigen presentation pathway has recently been enhanced with the identification that the tapasin-related protein TAPBPR is a second major histocompatibility complex (MHC) class I-specific chaperone. We sought to determine whether, like tapasin, TAPBPR can also influence MHC class I peptide selection by functioning as a peptide exchange catalyst. We show that TAPBPR can catalyse the dissociation of peptides from peptide-MHC I complexes, enhance the loading of peptide-receptive MHC I molecules, and discriminate between peptides based on affinity in vitro. In cells, the depletion of TAPBPR increased the diversity of peptides presented on MHC I molecules, suggesting that TAPBPR is involved in restricting peptide presentation. Our results suggest TAPBPR binds to MHC I in a peptide-receptive state and, like tapasin, works to enhance peptide optimisation. It is now clear there are two MHC class I specific peptide editors, tapasin and TAPBPR, intimately involved in controlling peptide presentation to the immune system.This is the final version of the article. It first appeared from eLife via http://dx.doi.org/10.755

Resourcefulness, reciprocity and reflexivity: the three Rs of partnership in sport for public health research

This paper explores the dynamics of research–policy–practice (RPP) partnerships in sport. Such partnerships, involving a diverse range of groups, have emerged as a response to: (1) a contemporary political prioritisation in the use of sport for health and wellbeing and (2) a parallel requirement for robust evidence of effectiveness and cost-effectiveness. A conceptual framework for understanding such RPP partnerships is proposed and discussed in relation to three overlapping characteristics; resourcefulness, reciprocity and reflexivity. The paper concludes that understanding these three Rs of RPP partnerships is a way to demythologise the role of sport in public health and present theoretically informed analyses about processes of knowledge production, dissemination and use. It is a conceptual framework which might also further an understanding of, and make public, issues concerning the legitimation of some forms of evidence over others, and potentially maximise the impact of the co-production of knowledge about sport for public health and wellbeing