Eosinophil peroxidase engages the HER2 receptor and induces integrin clustering with downstream signalling consequences.

Eosinophils account for 1 - 3% of peripheral blood leukocytes and accumulate a local inflammatory sites in allergic conditions such as asthma and allergic rhinitis. Eosinophils contain four cationic granule proteins, Eosinophil Peroxidase (EPO), Eosinophil Derived Neurotoxin (EDN), Eosinophil Cationic Protein (ECP) and Major Basic Protein (MBP) and all are highly toxic at high concentration. However, these eosinophil granule proteins exhibit positive effects at a lower, more physiological concentration, such as cell and tissue remodelling and growth factor receptor expression. Eosinophils localise to epithelial cells in vivo and this study looks at the effect of eosinophil granule proteins on human bronchial epithelial cells. In this study, we present evidence that EPO forms a complex with and activates the HER2 receptor, with consequent upregulation of HER2 receptor expression. This EPO-HER2 interaction is dependent on N-linked glycosylation. We also provide evidence that, subsequent to HER2 activation, EPO induces activation of pi integrin, activation of FAK and activation of ERK. The activation of FAK and p1 integrin is dependent on the initial activation of the HER2 receptor. The activation of FAK is independent of pi-integrin activation and the activation of ERK is delayed in the absence of pi integrin activation. We also found an EPOinduced, HER2-dependent upregulation of MUC4 at a transcriptional level. These results suggest that eosinophil localisation to epithelial cells, as seen in asthma and rhinitis, induces growth factor receptor expression and activation of subsequent downstream pathways associated with cell proliferation, all of which are necessary for the airway to repair and remodel after an inflammatory episode. EPO-induced upregulation of MUC4 gene expression indicates that eosinophils may also contribute to increased mucociliary clearance during an inflammatory attack

Eosinophil peroxidase activates cells by HER2 receptor engagement and β1-integrin clustering with downstream MAPK cell signaling

Eosinophils account for 1–3% of peripheral blood leukocytes and accumulate at sites of allergic inflammation, where they play a pathogenic role. Studies have shown that treatment with mepolizumab (an anti-IL-5 monoclonal antibody) is beneficial to patients with severe eosinophilic asthma, however, the mechanism of precisely how eosinophils mediate these pathogenic effects is uncertain. Eosinophils contain several cationic granule proteins, including Eosinophil Peroxidase (EPO). The main significance of this work is the discovery of EPO as a novel ligand for the HER2 receptor. Following HER2 activation, EPO induces activation of FAK and subsequent activation of β1-integrin, via inside-out signaling. This complex results in downstream activation of ERK1/2 and a sustained up regulation of both MUC4 and the HER2 receptor. These data identify a receptor for one of the eosinophil granule proteins and demonstrate a potential explanation of the proliferative effects of eosinophils.Health Research BoardWellcome Trus

A phase Ia study to assess the safety and immunogenicity of new malaria vaccine candidates ChAd63 CS administered alone and with MVA CS

BACKGROUND: Plasmodium falciparum (P. falciparum) malaria remains a significant cause of mortality and morbidity throughout the world. Development of an effective vaccine would be a key intervention to reduce the considerable social and economic impact of malaria. METHODOLOGY: We conducted a Phase Ia, non-randomized, clinical trial in 24 healthy, malaria-naïve adults of the chimpanzee adenovirus 63 (ChAd63) and modified vaccinia virus Ankara (MVA) replication-deficient viral vectored vaccines encoding the circumsporozoite protein (CS) of P. falciparum. RESULTS: ChAd63-MVA CS administered in a heterologous prime-boost regime was shown to be safe and immunogenic, inducing high-level T cell responses to CS. With a priming ChAd63 CS dose of 5×109 vp responses peaked at a mean of 1947 SFC/million PBMC (median 1524) measured by ELIspot 7 days after the MVA boost and showed a mixed CD4+/CD8+ phenotype. With a higher priming dose of ChAd63 CS dose 5×1010 vp T cell responses did not increase (mean 1659 SFC/million PBMC, median 1049). Serum IgG responses to CS were modest and peaked at day 14 post ChAd63 CS (median antibody concentration for all groups at day 14 of 1.3 µg/ml (range 0-11.9), but persisted throughout late follow-up (day 140 median antibody concentration groups 1B \u26 2B 0.9 µg/ml (range 0-4.7). CONCLUSIONS: ChAd63-MVA is a safe and highly immunogenic delivery platform for the CS antigen in humans which warrants efficacy testing. TRIAL REGISTRATION: ClinicalTrials.gov NCT01450280

Exploring the attitudes and experiences of adolescents with type 1 diabetes towards transition of care

Introduction Transition from adolescence to adult care is very challenging for most patients. Without appropriate appointments and education, adolescents can get lost to follow up within one-year of transitioning to adult care (Mistry et al. Diabet Med 32(7):881–885, 2015). Loss to follow-up can increase risks of adverse short and long term diabetes-related complications, with healthcare contacts mainly limited to crisis-based management (Iversen et al. Scand J Caring Sci 33(3):723–730, 2019). Aims The purpose of this study was to evaluate the patient’s perspective of the process of transition from paediatric to adult-based diabetes services in the Mid-West Region of Ireland. Methods We implemented a new transition clinic at University Hospital Limerick with the collaboration of paediatric and adult endocrinology teams. Eighteen patients opted to attend the clinic, but only 17 patients consented to participate in a qualitative assessment study and completed questionnaires before and after the transition clinic. Results and conclusion In terms of medical management, patients had a good understanding of hypoglycaemia and insulin dose adjustment principles, but were least comfortable with carbohydrate counting. Patients self-ranked their knowledge on driving and sexual health with a diagnosis of diabetes as poor, in comparison to understanding effects of alcohol and smoking on diabetes. Overall, a majority of the respondents felt more confident in moving to adult-care after attending the transition clinic

Local and systemic adverse events (AEs) possibly, probably or definitely related to vaccination shown as percentage of volunteers affected.

<p>(a) Post ChAd63 CS 5×10⁹ vp; (b) Post ChAd63 CS 5×10¹⁰ vp; (c) Post MVA CS 2×10⁸ pfu.</p

Summary of PBMC IFN-y ELIspot responses of volunteers in each group.

<p>Summed SFC/million PBMCs. (A) and (B) individual responses for groups 1A and 1B respectively over time. (C) and (D) show individual responses for groups 2A and 2B respectively over time. (E) median ELIspot response by group by time-point, changes were significant over time; for group 1B, day 0 to 14 p = 0.0063; day 14 to 63 p = 0.0148; day 0 to 63 p = 0.0002, Mann-Whitney test; and group 2B, day 0 to 14 p = 0.01; day 14 to 63 p = 0.0074; day 0 to 63 p = 0.0002, Mann-Whitney test. (F), (G) & (H) show individual responses by group at days 14, 63 and 84 or 90 respectively.</p

Multifunctional antigen specific cells.

<p>Percent of CD4⁺ and CD8⁺ PBMCs at day 63 producing 1–4 cytokines following stimulation with CS peptide pools.</p

Cytokine production by cell type and time-point assessed by 7 colour flow cytometry.

<p>Mean percent and standard error of the mean (SEM) of CD4+ and CD8+ PBMCs producing antigen-specific cytokines at given time-point post vaccination are shown for each cytokine. (A) percent CD4+ and (B) percent CD8+ PBMCs producing CD107a, IFNg, IL2 and TNFa at day 63. (C) percent CD4+ and (D) percent CD8+ PBMCs producing CD107a, IFNg, IL2 and TNFa at day 63. (E) percent CD4+ and (F) percent CD8+ PBMCs producing CD107a, IFNg, IL2 and TNFa at day 84.</p

CONSORT diagram of study progress.

<p>39 volunteers were screened. Reasons for not meeting the inclusion criteria in 7 excluded volunteers were: psychiatric morbidity (2), history of malignancy (2), one each of: history of headaches, Carbohydrate Deficient Transferrin (CDT) >3% and neutropenia.</p

Individual ELISpot responses in SFC/10⁶ PBMC at day 63 by peptide pool.

<p>Bar represents mean, whiskers; standard error of the mean.</p