Interference of Distinct Invariant Chain Regions with Superantigen Contact Area and Antigenic Peptide Binding Groove of HLA-DR

In the endoplasmic reticulum, MHC class II ab dimers associate with the trimeric invariant chain (li), generating a nine-subunit(abli)3 complex. In the presence of li, the peptide binding groove is blocked, so that loading with self or antigenic peptides can only occur after proteolytic removal of li in specialized post-Golgi compartments. The class 11-associated invariant chain peptide region of li (about residues 81-1 04) is known to mediate binding to class II molecules and blockade of the groove, but this does not exclude additional contact sites for li. Using a set of overlapping li peptides and recombinant soluble li, we demonstrate here that a large segment of Ii encompassing approximately residues 71 to 128 interacts with HLA-DR molecules. The N- and C-terminal regions of this Ii segment appear to bind outside the peptide groove to the contact area for the staphylococcal superantigen Staphylococcus aureus enterotoxin B on the a1 domain. The core region of this segment (residues 95-108)prevents binding of antigenic peptides, probably by interaction with the peptide groove. Occupation of the groove with antigenic peptides abolishes binding not only of the core region, but also that of those Ii peptides that bind outside the groove. These findings suggest the existence of distinct conformational states of class II molecules, with Ii binding preferentially to one form

Business Model Innovation vs. Business Model Inertia: the Role of Disruptive Technologies

This contribution addresses the impact of disruptive technologies on business model innovation. While such technologies have the potential to significantly alter the way in which businesses operate, business model inertia hinders companies from adopting the new technological possibilities. Little research has focused on the difficulties incumbents face when innovating their business models. By reviewing current literature on business model innovation, this paper summarizes challenges companies face when dealing with potential disruptive technologies and creating viable business models

Study protocol for Video Images about Decisions to Improve Ethical Outcomes with Palliative Care Educators (VIDEO-PCE): a pragmatic stepped wedge cluster randomised trial of older patients admitted to the hospital

Introduction Despite the known benefit to patients and families, discussions about goals, values and preferences for medical care in advancing serious illness often do not occur. Many system and clinician factors, such as patient and clinician reticence and shortage of specialty palliative care teams, contribute to this lack of communication. To address this gap, we designed an intervention to promote goals-of-care conversations and palliative care referrals in the hospital setting by using trained palliative care educators and video decision aids. This paper presents the rationale, design and methods for a trial aimed at addressing barriers to goals-of-care conversations for hospitalised adults aged 65 and older and those with Alzheimer’s disease and related Dementias, regardless of age.Methods and analysis The Video Image about Decisions to Improve Ethical Outcomes with Palliative Care Educators is a pragmatic stepped wedge, cluster randomised controlled trial, which aims to improve and extend goals-of-care conversations in the hospital setting with palliative care educators trained in serious illness communication and video decision aids. The primary outcome is the proportion of patients with goals-of-care documentation in the electronic health record. We estimate that over 9000 patients will be included.Ethics and dissemination The Institutional Review Board (IRB) at Boston Medical Center will serve as the single IRB of record for all regulatory and ethical aspects of this trial. BMC Protocol Number: H-41482. Findings will be presented at national meetings and in publications. This trial is registered at ClinicalTrials.gov.Trial registration number NCT04857060; ClinicalTrials.go