The Implementation of Assisted Dying in Quebec and Interdisciplinary Support Groups: What Role for Ethics?

The purpose of this text is to tell the story of the implementation of the Act Respecting End-of-Life Care, referred to hereafter as Law 2 (Gouvernement du Québec, 2014) with an emphasis on the ambiguous role of ethics in the Interdisciplinary Support Groups (ISGs), created by Quebec's Ministère de la santé et des services sociaux (MSSS). As established, ISGs provide "clinical, administrative and ethical support to health care professionals responding to a request for Medical aid in dying (MAiD)" (Gouvernement du Québec, 2015). It is suggested that their composition includes the participation of a person with an expertise in ethics. These ISGs represent an important innovation for stakeholders involved in MAiD. To date, no scientific research has specifically addressed ISGs and little research has been conducted in other jurisdictions on the roles, operations and practices of MAiD support structures, especially the implication of ethics. Several ISGs have certainly developed promising practices that could benefit all stakeholders in the wider field of ethics and end of life. We will explore the development of ISGs in Quebec as a support structure for MAiD by highlighting the role that ethics has played (and should play) in these morally and humanly challenging situations.

The transmembrane domain and luminal C-terminal region independently support invariant chain trimerization and assembly with MHCII into nonamers.

BACKGROUND: Invariant chain (CD74, Ii) is a multifunctional protein expressed in antigen presenting cells. It assists the ER exit of various cargos and serves as a receptor for the macrophage migration inhibitory factor. The newly translated Ii chains trimerize, a structural feature that is not readily understood in the context of its MHCII chaperoning function. Two segments of Ii, the luminal C-terminal region (TRIM) and the transmembrane domain (TM), have been shown to participate in the trimerization process but their relative importance and impact on the assembly with MHCII molecules remains debated. Here, we addressed the requirement of these domains in the trimerization of human Ii as well as in the oligomerization with MHCII molecules. We used site-directed mutagenesis to generate series of Ii and DR mutants. These were transiently transfected in HEK293T cells to test their cell surface expression and analyse their interactions by co-immunoprecipitations. RESULTS: Our results showed that the TRIM domain is not essential for Ii trimerization nor for intracellular trafficking with MHCII molecules. We also gathered evidence that in the absence of TM, TRIM allows the formation of multi-subunit complexes with HLA-DR. Similarly, in the absence of TRIM, Ii can assemble into high-order structures with MHCII molecules. CONCLUSIONS: Altogether, our data show that trimerization of Ii through either TM or TRIM sustains nonameric complex formation with MHCII molecules.

Effects of a projector-based hybrid virtual reality on pain in young children with burn injuries during hydrotherapy sessions: A within-subject randomized crossover trial.

AIM: The aim of this study was to examine the effect of a water-friendly Projector-Based Hybrid Virtual Reality (VR) dome environment combined with standard pharmacological treatment on pain in young children undergoing burn wound care in hydrotherapy. METHODS: This study was a prospective, within-subject crossover trial of 38 children aged 6 months to 7 years old (mean age=1.8 years old). Each hydrotherapy procedure was divided into two equivalent wound care segments (No hybrid VR during one segment vs. Hybrid VR during the other segment, treatment order was randomized). Pain was measured using the 0-10 FLACC (Face, Legs, Activity, Cry Consolability scale) and the 0-10 NRS-obs (Numerical Rating Scale-obs). RESULTS: Projector-Based Hybrid VR significantly reduced procedural pain levels measured by the FLACC (p=0.026) and significantly increased patients' comfort levels (p=0.002). Patients' pain levels rated by the nurses using the NRS-obs were non-significant between both groups (p=0.135). No side effects were reported. CONCLUSION: Projector-Based Hybrid VR helped in reducing the pain related to hydrotherapy procedures in young children with burn wound injuries. This is the first study using virtual reality distraction with young children, and our findings are especially important because a large percentage of pediatric burn patients are very young. Additional research and development are recommended. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02986464, registered on June 12, 2016.

Projector-based virtual reality dome environment for procedural pain and anxiety in young children with burn injuries: a pilot study.

BACKGROUND: Virtual reality (VR) is a non-pharmacological method to distract from pain during painful procedures. However, it was never tested in young children with burn injuries undergoing wound care. AIM: We aimed to assess the feasibility and acceptability of the study process and the use of VR for procedural pain management. METHODS: From June 2016 to January 2017, we recruited children from 2 months to 10 years of age with burn injuries requiring a hydrotherapy session in a pediatric university teaching hospital in Montreal. Each child received the projector-based VR intervention in addition to the standard pharmacological treatment. Data on intervention and study feasibility and acceptability in addition to measures on pain (Face, Legs, Activity, Cry, Consolability scale), baseline (Modified Smith Scale) and procedural (Procedure Behavior Check List) anxiety, comfort (OCCEB-BECCO [behavioral observational scale of comfort level for child burn victims]), and sedation (Ramsay Sedation Scale) were collected before, during, and after the procedure. Data analyses included descriptive and non-parametric inferential statistics. RESULTS: We recruited 15 children with a mean age of 2.2±2.1 years and a mean total body surface area of 5% (±4). Mean pain score during the procedure was low (2.9/10, ±3), as was the discomfort level (2.9/10, ±2.8). Most children were cooperative, oriented, and calm. Assessing anxiety was not feasible with our sample of participants. The prototype did not interfere with the procedure and was considered useful for procedural pain management by most health care professionals. CONCLUSION: The projector-based VR is a feasible and acceptable intervention for procedural pain management in young children with burn injuries. A larger trial with a control group is required to assess its efficacy.

ER egress of invariant chain isoform p35 requires direct binding to MHCII molecules and is inhibited by the NleA virulence factor of enterohaemorrhagic Escherichia coli.

Four invariant chain (Ii) isoforms assist the folding and trafficking of human MHC class II (MHCIIs). The main isoforms, Iip33 and Iip35, assemble in the ER into homo- and/or hetero-trimers. The sequential binding of up to three MHCII αß heterodimers to Ii trimers results in the formation of pentamers, heptamers and nonamers. MHCIIs are required to overcome the p35-encoded di-arginine (RxR) ER retention motif and to allow anterograde trafficking of the complex. Here, we show that inactivation of the RxR motif requires a direct cis interaction between p35 and the MHCII, precluding ER egress of some unsaturated Ii trimers. Interestingly, as opposed to MHCII/p33 complexes, those including p35 remained in the ER when co-expressed with the NleA protein of enterohaemorrhagic Escherichia coli. Taken together, our results demonstrate that p35 influences distinctively MHCII/Ii assembly and trafficking.

The invariant chain p35 isoform promotes formation of nonameric complexes with MHC II molecules.

Four different isoforms of the human invariant chain (Ii) have been described (p33, p35, p41 and p43). These heterotrimerize in the endoplasmic reticulum (ER) before associating with MHC class II molecules (MHCIIs). However, the final stoichiometry of the Ii/MHCII complex remains debated. This is particularly interesting as both p35 and p43 include a di-arginine motif that requires masking by MHCII to allow ER egress. Here, to functionally address the requirement for stoichiometric interactions, we used a recombinant DR heterodimer bearing its own cytoplasmic di-lysine ER-retention motif (DRKKAA). When coexpressed with p33 and a control myc-tagged DR (DRmyc), DRKKAA was retained in the ER but had little impact on surface expression of DRmyc. However, when coexpressed with p35, DRKKAA restricted the surface expression of DRmyc, indicating that Ii trimers can be loaded with more than one MHCII. Similar results were obtained using HLA-DQ instead of DRmyc, showing that a single trimeric Ii scaffold can include distinct MHCII isotypes. Altogether, these results demonstrate that the subunit stoichiometry of oligomeric Ii/MHCII complexes is influenced by p35.

MMTV superantigens coerce an unconventional topology between the TCR and MHC class II.

Mouse mammary tumor virus superantigens (vSAGs) are notorious for defying structural characterization, and a consensus has yet to be reached regarding their ability to bridge the TCR to MHC class II (MHCII). In this study, we determined the topology of the T cell signaling complex by examining the respective relation of vSAG7 with the MHCII molecule, MHCII-associated peptide, and TCR. We used covalently linked peptide/MHCII complexes to demonstrate that vSAG presentation is tolerant to variation in the protruding side chains of the peptide, but can be sensitive to the nature of the protruding N-terminal extension. An original approach in which vSAG was covalently linked to either MHCII chain confirmed that vSAG binds outside the peptide binding groove. Also, whereas the C-terminal vSAG segment binds to the MHCII α-chain in a conformation-sensitive manner, the membrane-proximal N-terminal domain binds the ß-chain. Because both moieties of the mature vSAG remain noncovalently associated after processing, our results suggest that vSAG crosslinks MHCII molecules. Comparing different T cell hybridomas, we identified key residues on the MHCII α-chain that are differentially recognized by the CDR3ß when engaged by vSAG. Finally, we show that the highly conserved tyrosine residue found in the vSAg TGXY motif is required for T cell activation. Our results reveal a novel SAG/MHCII/TCR architecture in which vSAGs coerce a near-canonical docking between MHCII and TCR that allows eschewing of traditional CDR3 binding with the associated peptide in favor of MHCII α-chain binding. Our findings highlight the plasticity of the TCR CDRs.

Exposing the Specific Roles of the Invariant Chain Isoforms in Shaping the MHC Class II Peptidome.

The peptide repertoire (peptidome) associated with MHC class II molecules (MHCIIs) is influenced by the polymorphic nature of the peptide binding groove but also by cell-intrinsic factors. The invariant chain (Ii) chaperones MHCIIs, affecting their folding and trafficking. Recent discoveries relating to Ii functions have provided insights as to how it edits the MHCII peptidome. In humans, the Ii gene encodes four different isoforms for which structure-function analyses have highlighted common properties but also some non-redundant roles. Another layer of complexity arises from the fact that Ii heterotrimerizes, a characteristic that has the potential to affect the maturation of associated MHCIIs in many different ways, depending on the isoform combinations. Here, we emphasize the peptide editing properties of Ii and discuss the impact of the various isoforms on the MHCII peptidome.

Evidence for a human leucocyte antigen-DM-induced structural change in human leucocyte antigen-DObeta.

Human leucocyte antigen (HLA)-DO is a non-classical major histocompatibility complex class II molecule which modulates the function of HLA-DM and the loading of antigenic peptides on molecules such as HLA-DR. The bulk of HLA-DO associates with HLA-DM and this interaction is critical for HLA-DO egress from the endoplasmic reticulum. HLA-DM assists the early steps of HLA-DO maturation presumably through the stabilization of the interactions between the N-terminal regions of the alpha and beta chains. To evaluate a possible role for HLA-DM in influencing the conformation of HLA-DO, we made use of a monoclonal antibody, Mags.DO5, that was raised against HLA-DO/DM complexes. Using transfected cells expressing mismatched heterodimers between HLA-DR and -DO chains, we found that the epitope for Mags.DO5 is located on the DObeta chain and that Mags.DO5 reactivity was increased upon cotransfection with HLA-DM. Our results suggest that HLA-DM influences the folding of HLA-DO in the endoplasmic reticulum. A mutant HLA-DO showing reduced capacity for endoplasmic reticulum egress was better recognized by Mags.DO5 in the presence of HLA-DM. On the other hand, an HLA-DO mutant capable of endoplasmic reticulum egress on its own was efficiently recognized by Mags.DO5, irrespective of the presence of HLA-DM. Taken together, our results suggest that HLA-DM acts as a private chaperone, directly assisting the folding of HLA-DO to promote egress from the endoplasmic reticulum.