In-vitro and in-vivo evidence for uncoupling of BCR internalization and signaling in chronic lymphocytic leukemia

B-cell receptor activation, occurring within lymph nodes, plays a key role in the pathogenesis of chronic lymphocytic leukemia and is linked to prognosis. As well as activation of downstream signaling, receptor ligation triggers internalization, transit to acidified endosomes and degradation of ligand-receptor complexes. In the present study we investigated the relationship between these two processes in normal and leukemic B-cells. We found that leukemic B-cells, particularly anergic cases lacking the capacity to initiate downstream signaling, internalize and accumulate ligand in acidified endosomes more efficiently than normal B-cells. Furthermore, ligation of either surface CD79B, a Bcell receptor component required for downstream signaling, or surface IgM by cognate agonistic antibody, showed that the two molecules internalize independently of each other in leukemic but not normal B-cells. Since association with surface CD79B is required for surface retention of IgM, this suggests that uncoupling of B-cell receptor internalization from signaling may be due to dissociation of these two molecules in leukemic cells. Comparison of lymph node with peripheral blood cells from chronic lymphocytic leukemia patients showed that, despite recent B-cell receptor activation, lymph node B-cells expressed higher levels of surface IgM. This surprising finding suggests that the B-cell receptors of lymph node and peripheral blood derived leukemic cells might be functionally distinct. Finally, long-term therapy with the Bruton’s tyrosine kinase inhibitors ibrutinib or acalabrutinib resulted in a switch to an anergic pattern of B-cell receptor function with reduced signaling capacity, surface IgM expression and more efficient internalization

Phenotype and immune function of lymph node and peripheral blood CLL cells are linked to transendothelial migration

everal lines of evidence suggest that homing of tumor cells to lymphoid tissue contributes to disease progression in chronic lymphocytic leukemia (CLL). Here, we demonstrate that lymph node (LN)-derived CLL cells possess a distinct phenotype, and exhibit enhanced capacity for T-cell activation and superior immune synapse formation when compared with paired peripheral blood (PB) samples. LN-derived CLL cells manifest a proliferative, CXCR4(dim)CD5(bright) phenotype compared with those in the PB and higher expression of T-cell activation molecules including CD80, CD86, and HLA-D-related (DR). In addition, LN-CLL cells have higher expression of α4β1 (CD49d) which, as well as being a co-stimulatory molecule, is required for CLL cells to undergo transendothelial migration (TEM) and enter the proliferation centers of the LNs. Using an in vitro system that models circulation and TEM, we showed that the small population of CLL cells that migrate are CXCR4(dim)CD5(bright) with higher CD49d, CD80, CD86, and HLA-DR compared with those that remain circulating; a phenotype strikingly similar to LN-derived CLL cells. Furthermore, sorted CD49d(hi) CLL cells showed an enhanced capacity to activate T cells compared with CD49d(lo) subpopulations from the same patient. Thus, although PB-CLL cells have a reduced capacity to form immune synapses and activate CD4(+) T cells, this was not the case for LN-CLL cells or those with the propensity to undergo TEM. Taken together, our study suggests that CLL cell immunologic function is not only modulated by microenvironmental interactions but is also a feature of a subpopulation of PB-CLL cells that are primed for lymphoid tissue homing and interaction with T cells

Global burden of 369 diseases and injuries in 204 countries and territories, 1990–2019: a systematic analysis for the Global Burden of Disease Study 2019

Background: In an era of shifting global agendas and expanded emphasis on non-communicable diseases and injuries along with communicable diseases, sound evidence on trends by cause at the national level is essential. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) provides a systematic scientific assessment of published, publicly available, and contributed data on incidence, prevalence, and mortality for a mutually exclusive and collectively exhaustive list of diseases and injuries. Methods: GBD estimates incidence, prevalence, mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) due to 369 diseases and injuries, for two sexes, and for 204 countries and territories. Input data were extracted from censuses, household surveys, civil registration and vital statistics, disease registries, health service use, air pollution monitors, satellite imaging, disease notifications, and other sources. Cause-specific death rates and cause fractions were calculated using the Cause of Death Ensemble model and spatiotemporal Gaussian process regression. Cause-specific deaths were adjusted to match the total all-cause deaths calculated as part of the GBD population, fertility, and mortality estimates. Deaths were multiplied by standard life expectancy at each age to calculate YLLs. A Bayesian meta-regression modelling tool, DisMod-MR 2.1, was used to ensure consistency between incidence, prevalence, remission, excess mortality, and cause-specific mortality for most causes. Prevalence estimates were multiplied by disability weights for mutually exclusive sequelae of diseases and injuries to calculate YLDs. We considered results in the context of the Socio-demographic Index (SDI), a composite indicator of income per capita, years of schooling, and fertility rate in females younger than 25 years. Uncertainty intervals (UIs) were generated for every metric using the 25th and 975th ordered 1000 draw values of the posterior distribution. Findings: Global health has steadily improved over the past 30 years as measured by age-standardised DALY rates. After taking into account population growth and ageing, the absolute number of DALYs has remained stable. Since 2010, the pace of decline in global age-standardised DALY rates has accelerated in age groups younger than 50 years compared with the 1990–2010 time period, with the greatest annualised rate of decline occurring in the 0–9-year age group. Six infectious diseases were among the top ten causes of DALYs in children younger than 10 years in 2019: lower respiratory infections (ranked second), diarrhoeal diseases (third), malaria (fifth), meningitis (sixth), whooping cough (ninth), and sexually transmitted infections (which, in this age group, is fully accounted for by congenital syphilis; ranked tenth). In adolescents aged 10–24 years, three injury causes were among the top causes of DALYs: road injuries (ranked first), self-harm (third), and interpersonal violence (fifth). Five of the causes that were in the top ten for ages 10–24 years were also in the top ten in the 25–49-year age group: road injuries (ranked first), HIV/AIDS (second), low back pain (fourth), headache disorders (fifth), and depressive disorders (sixth). In 2019, ischaemic heart disease and stroke were the top-ranked causes of DALYs in both the 50–74-year and 75-years-and-older age groups. Since 1990, there has been a marked shift towards a greater proportion of burden due to YLDs from non-communicable diseases and injuries. In 2019, there were 11 countries where non-communicable disease and injury YLDs constituted more than half of all disease burden. Decreases in age-standardised DALY rates have accelerated over the past decade in countries at the lower end of the SDI range, while improvements have started to stagnate or even reverse in countries with higher SDI. Interpretation: As disability becomes an increasingly large component of disease burden and a larger component of health expenditure, greater research and developm nt investment is needed to identify new, more effective intervention strategies. With a rapidly ageing global population, the demands on health services to deal with disabling outcomes, which increase with age, will require policy makers to anticipate these changes. The mix of universal and more geographically specific influences on health reinforces the need for regular reporting on population health in detail and by underlying cause to help decision makers to identify success stories of disease control to emulate, as well as opportunities to improve. Funding: Bill & Melinda Gates Foundation. © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 licens

1641 Depositions: Sharing our history, building a legacy

This research impact case study highlights the multiple impacts stemming from the 1641 Depositions Project. The document summarises how this flagship transdisciplinary digital humanities endeavour has engaged with publics inside and outside academia and transformed our understanding of how the controversial events of the mid-seventeenth century are recorded and remembered

The Werner syndrome gene product (WRN): a repressor of hypoxia-inducible factor-1 activity

Hypoxia-inducible factor-1 (HIF-1) is a decisive element for the transcriptional regulation of genes essential for adaptation to low oxygen conditions. HIF-1 is also implicated in the molecular mechanisms of ageing. Here, we show that the cellular depletion of WRN protein (by siRNA targeting) leads to increased HIF-1 complex stabilization and activation. HIF-1 activation in the absence of WRN involves the generation of mitochondrial reactive oxygen species (mtROS) since SkQ1, a mitochondrial-targeted antioxidant, and stigmatellin, an inhibitor of mitochondrial complex III, blocked increased HIF-1 levels. Ascorbate, an essential co-factor involved in HIF-1 stability, was decreased in WRN-depleted cells. Interestingly, expression levels of GLUT1, a known dehydroascorbic acid transporter, were also decreased in WRN-depleted cells. Ascorbate supplementation of WRN-depleted cells led to a dose-dependent inhibition of HIF-1 activation. These results indicate that WRN protein regulates HIF-1 activation by affecting mitochondrial ROS production and intracellular ascorbate levels. This work provides a novel mechanistic link between HIF-1 activity and different age-associated pathologies

Exploring research team members’ and trial participants’ perceptions of acceptability and implementation within one videoconference-based supportive care program for individuals affected by systemic sclerosis during COVID-19: a qualitative interview study

The SPIN-CHAT Program was designed to support mental health among individuals with systemic sclerosis (SSc; commonly known as scleroderma) and at least mild anxiety symptoms at the onset of COVID-19. The program was formally evaluated in the SPIN-CHAT Trial. Little is known about program and trial acceptability, and factors impacting implementation from the perspectives of research team members and trial participants. Thus, the propose of this follow-up study was to explore research team members’ and trial participants’ experiences with the program and trial to identify factors impacting acceptability and successful implementation. Data were collected cross-sectionally through one-on-one, videoconference-based, semi-structured interviews with 22 research team members and 30 purposefully recruited trial participants (Mage = 54.9, SD = 13.0 years). A social constructivist paradigm was adopted, and data were analyzed thematically. Data were organized into seven themes: (i) getting started: the importance of prolonged engagement and exceeding expectations; (ii) designing the program and trial: including multiple features; (iii) training: research team members are critical to positive program and trial experiences; (iv) offering the program and trial: it needs to be flexible and patient-oriented; (v) maximizing engagement: navigating and managing group dynamics; (vi) delivering a videoconference-based supportive care intervention: necessary, appreciated, and associated with some barriers; and (vii) refining the program and trial: considering modification when offered beyond the period of COVID-19 restrictions. Trial participants were satisfied with and found the SPIN-CHAT Program and Trial to be acceptable. Results offer implementation data that can guide the design, development, and refinement of other supportive care programs seeking to promote psychological health during and beyond COVID-19

A qualitative interview study exploring the psychological health impacts of the SPIN-CHAT program among people with systemic sclerosis at the onset of COVID-19: perceptions of trial participants and research team members

PurposeExplore trial participants’ and research team members’ perceptions of the impact of the videoconference-based, supportive care program (SPIN-CHAT Program) during early COVID-19 for individuals with systemic sclerosis (SSc).MethodsData were collected cross-sectionally. A social constructivist paradigm was adopted, and one-on-one videoconference-based, semi-structured interviews were conducted with SPIN-CHAT Trial participants and research team members. A hybrid inductive-deductive approach and reflexive thematic analysis were used.ResultsOf the 40 SPIN-CHAT Trial participants and 28 research team members approached, 30 trial participants (Mean age = 54.9; SD = 13.0 years) and 22 research team members agreed to participate. Those who took part in interviews had similar characteristics to those who declined. Five themes were identified: (1) The SPIN-CHAT Program conferred a range of positive psychological health outcomes, (2) People who don’t have SSc don’t get it: The importance of SSc-specific programming, (3) The group-based format of the SPIN-CHAT Program created a safe space to connect and meet similar others, (4) The structure and schedule of the SPIN-CHAT Program reduced feelings of boredom and contributed to enhanced psychological health, (5) The necessity of knowledge, skills, and tools to self-manage SSc and navigate COVID-19.ConclusionParticipants’ and research team members’ perspectives elucidated SPIN-CHAT Program benefits and how these benefits may have been realized. Results underscore the importance of social support from similar others, structure, and self-management to enhance psychological health during COVID-19