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Chronic wasting disease (CWD) is a cervid prion disease with unknown zoonotic potential that might pose a risk to humans who are exposed. To assess the potential of CWD to infect human neural tissue, we used human cerebral organoids with 2 different prion genotypes, 1 of which has previously been associated with susceptibility to zoonotic prion disease. We exposed organoids from both genotypes to high concentrations of CWD inocula from 3 different sources for 7 days, then screened for infection periodically for up to 180 days. No de novo CWD propagation or deposition of protease-resistant forms of human prions was evident in CWD-exposed organoids. Some persistence of the original inoculum was detected, which was equivalent in prion gene knockout organoids and thus not attributable to human prion propagation. Overall, the unsuccessful propagation of CWD in cerebral organoids supports a strong species barrier to transmission of CWD prions to humans.

Abstract Background Sporadic Creutzfeldt-Jakob disease (sCJD), the most common human prion disease, is a fatal neurodegenerative disease with currently no treatment options. Stem cell therapy for neurodegenerative diseases is emerging as a possible treatment option. However, while there are a few clinical trials for other neurodegenerative disorders such as Parkinson’s disease, prion disease cell therapy research has so far been confined to animal models. Methods Here, we use a novel approach to study cell therapies in sCJD using a human cerebral organoid model. Cerebral organoids can be infected with sCJD prions allowing us to assess how neural precursor cell (NPC) therapy impacts the progression of sCJD. After 90 days of sCJD or mock infection, organoids were either seeded with NPCs or left unseeded and monitored for cellular composition changes, prion infection parameters and neuroelectrophysiological function at 180 days post-infection. Results Our results showed NPCs integrated into organoids leading to an increase in neuronal markers and changes in cell signaling irrespective of sCJD infection. Although a small, but significant, decrease in protease-resistant PrP deposition was observed in the CJD-infected organoids that received the NPCs, other disease-associated parameters showed minimal changes. However, the NPCs had a beneficial impact on organoid function following infection. sCJD infection caused reduction in neuronal spike rate and mean burst spike rate, indicative of reduced action potentials. NPC seeding restored these electrophysiological parameters to the uninfected control level. Conclusions Together with the previous animal studies, our results support that cell therapy may have some functional benefit for the treatment of human prion diseases.

Abstract Human cerebral organoids (COs) are three-dimensional self-organizing cultures of cerebral brain tissue differentiated from induced pluripotent stem cells. We have recently shown that COs are susceptible to infection with different subtypes of Creutzfeldt–Jakob disease (CJD) prions, which in humans cause different manifestations of the disease. The ability to study live human brain tissue infected with different CJD subtypes opens a wide array of possibilities from differentiating mechanisms of cell death and identifying neuronal selective vulnerabilities to testing therapeutics. However, the question remained as to whether the prions generated in the CO model truly represent those in the infecting inoculum. Mouse models expressing human prion protein are commonly used to characterize human prion disease as they reproduce many of the molecular and clinical phenotypes associated with CJD subtypes. We therefore inoculated these mice with COs that had been infected with two CJD subtypes (MV1 and MV2) to see if the original subtype characteristics (referred to as strains once transmitted into a model organism) of the infecting prions were maintained in the COs when compared with the original human brain inocula. We found that disease characteristics caused by the molecular subtype of the disease associated prion protein were similar in mice inoculated with either CO derived material or human brain material, demonstrating that the disease associated prions generated in COs shared strain characteristics with those in humans. As the first and only in vitro model of human neurodegenerative disease that can faithfully reproduce different subtypes of prion disease, these findings support the use of the CO model for investigating human prion diseases and their subtypes.

Richter’s Transformation is a treatment-resistant and fatal progression from Chronic Lymphocytic Leukemia (CLL) to an aggressive lymphoma. Here, the authors show that PRMT5 is upregulated months prior to and after transformation, PRMT5 overexpression in a CLL mouse model leads to increased risk of transformation, and that targeted PRMT5 inhibition prolongs survival and delays disease development.

Abstract Chronic wasting disease (CWD) is a prion disease of cervids including deer, elk, reindeer, and moose. Human consumption of cervids is common, therefore assessing the risk potential of CWD transmission to humans is critical. In a previous study, we tested CWD transmission via intracerebral inoculation into transgenic mice (tg66 and tgRM) that over-expressed human prion protein. Mice screened by traditional prion detection assays were negative. However, in a group of 88 mice screened by the ultrasensitive RT-QuIC assay, we identified 4 tg66 mice that produced inconsistent positive RT-QuIC reactions. These data could be false positive reactions, residual input inoculum or indicative of subclinical infections suggestive of cross species transmission of CWD to humans. Additional experiments were required to understand the nature of the prion seeding activity in this model. In this manuscript, second passage experiments using brains from mice with weak prion seeding activity showed they were not infectious to additional recipient tg66 mice. Clearance experiments showed that input CWD prion seeding activity was eliminated by 180 days in tg66 mice and PrPKO mice, which are unable to replicate prion protein, indicating that the weak positive levels of seeding activity detected at later time points was not likely residual inoculum. The failure of CWD prions to cause disease in tg66 after two sequential passages suggested that a strong species barrier prevented CWD infection of mice expressing human prion protein.

Abstract Cardiomyopathy is a co-morbidity of some prion diseases including genetic disease caused by mutations within the PrP gene (PRNP). Although the cellular prion protein (PrP) has been shown to protect against cardiotoxicity caused by oxidative stress, it is unclear if the cardiomyopathy is directly linked to PrP dysfunction. We differentiated cardiomyocyte cultures from donor human induced pluripotent stem cells and found a direct influence of the PRNP E200K mutation on cellular function. The PRNP E200K cardiomyocytes showed abnormal function evident in the irregularity of the rapid repolarization; a phenotype comparable with the dysfunction reported in Down Syndrome cardiomyocytes. PRNP E200K cardiomyocyte cultures also showed increased mitochondrial superoxide accompanied by increased mitochondrial membrane potential and dysfunction. To confirm that the changes were due to the E200K mutation, CRISPR-Cas9 engineering was used to correct the E200K carrier cells and insert the E200K mutation into control cells. The isotype matched cardiomyocytes showed that the lysine expressing allele does directly influence electrophysiology and mitochondrial function but some differences in severity were apparent between donor lines. Our results demonstrate that cardiomyopathy in hereditary prion disease may be directly linked to PrP dysfunction.

Cellular prion protein (PrPC) protects neurons against oxidative stress damage. This role is lost upon its misfolding into insoluble prions in prion diseases, and correlated with cytoskeletal breakdown and neurophysiological deficits. Here we used mouse neuronal models to assess how PrPC protects the neuronal cytoskeleton, and its role in network communication, from oxidative stress damage. Oxidative stress was induced extrinsically by potassium superoxide (KO2) or intrinsically by Mito-Paraquat (MtPQ), targeting the mitochondria. In mouse neural lineage cells, KO2 was damaging to the cytoskeleton, with cells lacking PrPC (PrP-/-) damaged more than wild-type (WT) cells. In hippocampal slices, KO2 acutely inhibited neuronal communication in WT controls without damaging the cytoskeleton. This inhibition was not observed in PrP-/- slices. Neuronal communication and the cytoskeleton of PrP-/- slices became progressively disrupted and degenerated post-recovery, whereas the dysfunction in WT slices recovered in 5 days. This suggests that the acute inhibition of neuronal activity in WT slices in response to KO2 was a neuroprotective role of PrPC, which PrP-/- slices lacked. Heterozygous expression of PrPC was sufficient for this neuroprotection. Further, hippocampal slices from mice expressing PrPC without its GPI anchor (PrPGPI-/-) displayed acute inhibition of neuronal activity by KO2. However, they failed to restore normal activity and cytoskeletal formation post-recovery. This suggests that PrPC facilitates the depressive response to KO2 and its GPI anchoring is required to restore KO2-induced damages. Immuno spin-trapping showed increased radicals formed on the filamentous actin of PrP-/- and PrPGPI-/- slices, but not WT and PrP+/- slices, post-recovery suggesting ongoing dysregulation of redox balance in the slices lacking GPI-anchored PrPC. The MtPQ treatment of hippocampal slices temporarily inhibited neuronal communication independent of PrPC expression. Overall, GPI-anchored PrPC alters synapses and neurotransmission to protect and repair the neuronal cytoskeleton, and neuronal communication, from extrinsically induced oxidative stress damages.

Fatal familial insomnia (FFI) is a rare neurodegenerative disease caused by a dominantly inherited single amino acid substitution (D178N) within the prion protein (PrP). No in vitro human brain tissue model for this disease has previously been available. Consequently, how this mutation exerts its damaging effect on brain cells is still unknown. Using CRISPR-Cas9 engineered induced pluripotent stem cells, we made D178N cerebral organoids and compared these with isotype control organoids. We found that, in the absence of other hallmarks of FFI, the D178N organoids exhibited astrogliosis with cellular oxidative stress. Abnormal post-translational processing of PrP was evident but no tissue deposition or propagation of mis-folded PrP isoforms were observed. Neuronal electrophysiological function was compromised and levels of neurotransmitters, particularly acetylcholine and GABA, altered. Underlying these dysfunctions were changes in cellular energy homeostasis, with substantially increased glycolytic and Krebs cycle intermediates, and greater mitochondrial activity. This increased energy demand in D178N organoids was associated with increased mitophagy and depletion of lipid droplets, in turn resulting in shifts of cellular lipid composition. Using a double mutation (178NN) we could confirm that most changes were caused by the presence of the mutation rather than interaction with PrP molecules lacking the mutation. Our data strongly suggests that shifting biosynthetic intermediates and oxidative stress, caused by an imbalance of energy supply and demand, results in astrogliosis with compromised neuronal activity in FFI organoids. They further support that many of the disease associated changes are due to a corruption of PrP function and do not require propagation of PrP mis-folding.

Some genes that are part of balanced translocations are reported as drivers for tumourigenesis. Here, the authors report a translocation involving MTCP1 in chronic lymphocytic leukemia and show that MTCP1 overexpression leads to the disease in a murine model.

Abstract Background Past experiments studying innate immunity in the central nervous system (CNS) utilized microglia obtained from neonatal mouse brain, which differ developmentally from adult microglia. These differences might impact our current understanding of the role of microglia in CNS development, function, and disease. Methods Cytokine protein secretion was compared in ex vivo P3 and adult microglial cultures after exposure to agonists for three different toll-like receptors (TLR4, lipopolysaccharide [LPS]; TLR7, imiquimod [IMQ]; and TLR9, CpG Oligodeoxynucleotide [CpG-ODN] 1585). In addition, changes in inflammatory gene expression in ex vivo adult microglia in response to the TLR agonists was assessed. Furthermore, in vivo experiments evaluated changes in gene expression associated with inflammation and TLR signaling in brains of mice with or without treatment with PLX5622 to reduce microglia. Results Ex vivo adult and P3 microglia increased cytokine secretion when exposed to TLR4 agonist LPS and to TLR7 agonist IMQ. However, adult microglia decreased expression of numerous genes after exposure to TLR 9 agonist CpG-ODN 1585. In contrast, in vivo studies indicated a core group of inflammatory and TLR signaling genes increased when each of the TLR agonists was introduced into the CNS. Reducing microglia in the brain led to decreased expression of various inflammatory and TLR signaling genes. Mice with reduced microglia showed extreme impairment in upregulation of genes after exposure to TLR7 agonist IMQ. Conclusions Cultured adult microglia were more reactive than P3 microglia to LPS or IMQ exposure. In vivo results indicated microglial influences on neuroinflammation were agonist specific, with responses to TLR7 agonist IMQ more dysregulated in mice with reduced microglia. Thus, TLR7-mediated innate immune responses in the CNS appeared more dependent on the presence of microglia. Furthermore, partial responses to TLR4 and TLR9 agonists in mice with reduced microglia suggested other cell types in the CNS can compensate for their absence.

Abstract Background Exportin 1 (XPO1/CRM1) is a key mediator of nuclear export with relevance to multiple cancers, including chronic lymphocytic leukemia (CLL). Whole exome sequencing has identified hot-spot somatic XPO1 point mutations which we found to disrupt highly conserved biophysical interactions in the NES-binding groove, conferring novel cargo-binding abilities and forcing cellular mis-localization of critical regulators. However, the pathogenic role played by change-in-function XPO1 mutations in CLL is not fully understood. Methods We performed a large, multi-center retrospective analysis of CLL cases (N = 1286) to correlate nonsynonymous mutations in XPO1 (predominantly E571K or E571G; n = 72) with genetic and epigenetic features contributing to the overall outcomes in these patients. We then established a mouse model with over-expression of wildtype (wt) or mutant (E571K or E571G) XPO1 restricted to the B cell compartment (Eµ-XPO1). Eµ-XPO1 mice were then crossed with the Eµ-TCL1 CLL mouse model. Lastly, we determined crystal structures of XPO1 (wt or E571K) bound to several selective inhibitors of nuclear export (SINE) molecules (KPT-185, KPT-330/Selinexor, and KPT-8602/Eltanexor). Results We report that nonsynonymous mutations in XPO1 associate with high risk genetic and epigenetic features and accelerated CLL progression. Using the newly-generated Eµ-XPO1 mouse model, we found that constitutive B-cell over-expression of wt or mutant XPO1 could affect development of a CLL-like disease in aged mice. Furthermore, concurrent B-cell expression of XPO1 with E571K or E571G mutations and TCL1 accelerated the rate of leukemogenesis relative to that of Eµ-TCL1 mice. Lastly, crystal structures of E571 or E571K-XPO1 bound to SINEs, including Selinexor, are highly similar, suggesting that the activity of this class of compounds will not be affected by XPO1 mutations at E571 in patients with CLL. Conclusions These findings indicate that mutations in XPO1 at E571 can drive leukemogenesis by priming the pre-neoplastic lymphocytes for acquisition of additional genetic and epigenetic abnormalities that collectively result in neoplastic transformation.

Abstract Acute myeloid leukemia (AML) is a heterogeneous and complex disease, and treatments for this disease have not been curative for the majority of patients. In younger patients, internal tandem duplication of FLT3 (FLT3-ITD) is a common mutation for which two inhibitors (midostaurin and gilteritinib) with varied potency and specificity for FLT3 are clinically approved. However, the high rate of relapse or failed initial response of AML patients suggests that the addition of a second targeted therapy may be necessary to improve efficacy. Using an unbiased large-scale CRISPR screen, we genetically identified BCL2 knockout as having synergistic effects with an approved FLT3 inhibitor. Here, we provide supportive studies that validate the therapeutic potential of the combination of FLT3 inhibitors with venetoclax in vitro and in vivo against multiple models of FLT3-ITD-driven AML. Our unbiased approach provides genetic validation for co-targeting FLT3 and BCL2 and repurposes CRISPR screening data, utilizing the genome-wide scope toward mechanistic understanding.

Space for living in new build houses in the UK is at premium and households have more stuff than ever before. The way this stuff is accommodated in dwellings can significantly affect residents’ quality of life and well-being. This paper presents a new conceptualisation of material possessions that could be of use to those involved in housing design. Three universal characteristics of material possessions; value, temporality and visibility are used to identify the space in the home that possessions might require. A conceptual framework that integrates these characteristics with spatial information about the interior of the home is developed. The paper argues that the conceptual framework could help designers, policymakers and house builders to better understand first the nature of material possessions, and second how those possessions could be accommodated in contemporary homes, ultimately supporting improved quality of life and wellbeing for households.

Abstract Background Prion diseases and prion-like disorders, including Alzheimer’s disease and Parkinson’s disease, are characterized by gliosis and accumulation of misfolded aggregated host proteins. Ablating microglia in prion-infected brain by treatment with the colony-stimulating factor-1 receptor (CSF-1R) inhibitor, PLX5622, increased accumulation of misfolded prion protein and decreased survival time. Methods To better understand the role of glia during neurodegeneration, we used RNA-seq technology, network analysis, and hierarchical cluster analysis to compare gene expression in brains of prion-infected versus mock-inoculated mice. Comparisons were also made between PLX5622-treated prion-infected mice and untreated prion-infected mice to assess mechanisms involved in disease acceleration in the absence of microglia. Results RNA-seq and network analysis suggested that microglia responded to prion infection through activation of integrin CD11c/18 and did not adopt the expression signature associated with other neurodegenerative disease models. Instead, microglia acquired an alternative molecular signature late in the disease process. Furthermore, astrocytes expressed a signature pattern of genes which appeared to be specific for prion diseases. Comparisons were also made with prion-infected mice treated with PLX5622 to assess the impact of microglia ablation on astrocyte gene expression during prion infection. In the presence of microglia, a unique mix of transcripts associated with A1- and A2-reactive astrocytes was increased in brains of prion-infected mice. After ablation of microglia, this reactive astrocyte expression pattern was enhanced. Thus, after prion infection, microglia appeared to decrease the overall A1/A2-astrocyte responses which might contribute to increased survival after infection. Conclusions RNA-seq analysis indicated dysregulation of over 300 biological processes within the CNS during prion disease. Distinctive microglia- and astrocyte-associated expression signatures were identified during prion infection. Furthermore, astrogliosis and the unique astrocyte-associated expression signature were independent of microglial influences. Astrogliosis and the unique astrocyte-associated gene expression pattern were increased when microglia were ablated. Our findings emphasize the potential existence of alternative pathways for activating the A1/A2 paradigm in astrocytes during neurodegenerative disease.

Microglia (MG) are critical to host defense during prion infection, but the mechanism(s) of this neuroprotection are poorly understood. To better examine the influence of MG during prion infection, we reduced MG in the brains of C57BL/10 mice using PLX5622 and assessed prion clearance and replication using multiple approaches that included bioassay, immunohistochemistry, and Real-Time Quaking Inducted Conversion (RT-QuIC). We also utilized a strategy of intermittent PLX5622 treatments to reduce MG and allow MG repopulation to test whether new MG could alter prion disease progress. Lastly, we investigated the influence of MG using tga20 mice, a rapid prion model that accumulates fewer pathological features and less PrPres in the infected brain. In C57BL/10 mice we found that MG were excluded from the inoculation site early after infection, but Iba1 positive infiltrating monocytes/macrophage were present. Reducing MG in the brain prior to prion inoculation did not increase susceptibility to prion infection. Short intermittent treatments with PLX5622 in prion infected C57BL/10 mice after 80 dpi were unsuccessful at altering the MG population, gliosis, or survival. Additionally, MG depletion using PLX5622 in tga20 mice had only a minor impact on prion pathogenesis, indicating that the presence of MG might be less important in this fast model with less prion accumulation. In contrast to the benefits of MG against prion disease in late stages of disease, our current experiments suggest MG do not play a role in early prion pathogenesis, clearance, or replication.

Prion diseases are a group of rare, transmissible, and invariably fatal neurodegenerative diseases that affect both humans and animals. The cause of these diseases is misfolding of the prion protein into pathological isoforms called prions. Of all human prion diseases, 10-15% of cases are genetic and the E200K mutation, which causes familial Creutzfeldt-Jakob disease (CJD), is the most prevalent. For both sporadic and genetic disease, it remains uncertain as to how initial protein misfolding is triggered. Prior studies have linked protein misfolding with oxidative stress insults, deregulated interactions with cellular cofactors, and viral infections. Our previous work developed a cerebral organoid (CO) model using human induced pluripotent stem cells containing the E200K mutation. COs are three-dimensional human neural tissues that permit the study of host genetics and environmental factors that contribute to disease onset. Isogenically matched COs with and without the E200K mutation were used to investigate the propensity of E200K PrP to misfold following cellular insults associated with oxidative stress. Since viral infections have also been associated with oxidative stress and neurodegenerative diseases, we additionally investigated the influence of Herpes Simplex Type-1 virus (HSV1), a neurotropic virus that establishes life-long latent infection in its host, on E200K PrP misfolding. While COs proved to be highly infectable with HSV1, neither acute nor latent infection, or direct oxidative stress insult, resulted in evidence of E200K prion misfolding. We conclude that misfolding into seeding-active PrP species is not readily induced by oxidative stress or HSV1 in our organoid system.

Contraceptive self-care interventions are a promising approach to improving reproductive health. Reproductive empowerment, the capacity of individuals to achieve their reproductive goals, is recognised as a component of self-care. An improved understanding of the relationship between self-care and empowerment is needed to advance the design, implementation and scale-up of self-care interventions. We conducted a systematic review of the peer-reviewed and grey literature published from 2010 through 2020 to assess the relationship between reproductive empowerment and access, acceptability, use or intention to use contraceptive self-care. Our review adheres to PRISMA guidelines and is registered in PROSPERO (ID CRD42020205235). A total of 3036 unique records were screened and 37 studies met our inclusion criteria. Most studies were conducted in high-income countries, were cross-sectional and had high risk of bias. Almost half included only women. Over 80% investigated male condoms. All but one study focused on use of self-care. We found positive relationships between condom use self-efficacy and use of/intention to use condoms. We found similar evidence for other self-care contraceptive methods, but the low number of studies and quality of the evidence precludes drawing strong conclusions. Few studies assessed causal relationships between empowerment and self-care, indicating that further research is warranted. Other underexplored areas include research on power with influential groups besides sexual partners, methods other than condoms, and access and acceptability of contraceptive self-care. Research using validated empowerment measures should be conducted in diverse geographies and populations including adolescents and men.

Objective There is contrasting evidence on the relationship between socioeconomic status (SES) and age-related macular degeneration (AMD), the most common cause of visual impairment (VI) in developed countries. This study examines the relationship between SES, cardiovascular risk factors and self-reported AMD.Methods and analysis Over 500000 people participated in the UK Biobank study from 2006 to 2019, with sociodemographic data and clinical measurements collected using standardised procedures. Visual acuity was measured in 117907 participants with VI defined as LogMAR ≤0.3. We used logistic regression to examine the cross-sectional associations between SES and self-reported AMD.Results Self-reported AMD was available for 133339 participants aged 50 and older. People reporting AMD had higher academic qualifications, lower income, were unable to work due to disability, have higher BMI, diabetes and vascular heart disease after adjusting for age and sex. In a multivariable analysis, higher income was protective of AMD and economic inactivity due to disability increased the odds of AMD (2.02, 95% CI 1.13 to 3.61). Both associations were independent of cardiovascular factors, but was no longer significant after adjusting for VI.Conclusions The association between education, employment and household income with AMD was independent of cardiovascular risk factors.

Inhabitants of UK housing have more possessions than ever, whilst space for living in standardised houses is at a premium. The acquisition of material possessions, and how it affects both space and inhabitants’ wellbeing, has not previously been considered in architectural practice or housing policy research fields. This paper addresses this gap, by exploring how practising architects design for the storage of material possessions in housing. For the first time, it places storage practices at the centre of housing design thinking, by engaging practising architects in a design intervention to explore original design solutions that support inhabitants’ lives and lifestyles, and therefore their wellbeing. The study uses a new storage-focused conceptual design framework to seek design knowledge, to better understand how storage practices could be considered when designing. The findings have implications for design practice research, providing an account of how architects consider storage in housing design, drawing on novel design intervention methods.

Abstract Degeneration of photoreceptors in the retina is a major cause of blindness in humans. Often retinal degeneration is due to inheritance of mutations in genes important in photoreceptor (PR) function, but can also be induced by other events including retinal trauma, microvascular disease, virus infection or prion infection. The onset of apoptosis and degeneration of PR neurons correlates with invasion of the PR cellular areas by microglia or monocytes, suggesting a causal role for these cells in pathogenesis of PR degenerative disease. To study the role of microglia in prion-induced retinal disease, we fed prion-infected mice a CSF-1 receptor blocking drug, PLX5622, to eliminate microglia in vivo, and the effects on retinal degeneration were analyzed over time. In mice not receiving drug, the main inflammatory cells invading the degenerating PR areas were microglia, not monocytes. Administration of PLX5622 was highly effective at ablating microglia in retina. However, lack of microglia during prion infection did not prevent degeneration of PR cells. Therefore, microglia were not required for the PR damage process during prion infection. Indeed, mice lacking microglia had slightly faster onset of PR damage. Similar results were seen in C57BL/10 mice and transgenic mice expressing GFP or RFP on microglia and monocytes, respectively. These results were supported by experiments using prion-infected Cx3cr1 knockout mice without PLX5622 treatment, where microglial expansion in retina was delayed, but PR degeneration was not. Contrary to predictions, microglia were not a causative factor in retinal damage by prion infection. Instead, newly generated PrPSc accumulated around the inner segment region of the PR cells and appeared to correlate with initiation of the pathogenic process in the absence of microglia.

There are currently no validated methods for the diagnosis of prion disease at the preclinical stage. Here the authors show that serial protein misfolding cyclic amplification and real-time quaking-induced conversion can be used to detect prions in the skin of prion-inoculated hamsters and humanized transgenic mice at early preclinical stages.

Abstract Chronic wasting disease (CWD) is a fatal prion disease which infects deer, elk and moose. CWD was first described as a wasting syndrome in captive deer in Colorado and Wyoming wildlife facilities from 1967 to 1979. Currently, CWD has been reported in 26 states of the USA, three Canadian provinces, South Korea, Norway and Finland. Since human consumption of cervids is common, it is critical to determine if CWD can infect humans. Published research, including epidemiologic studies and transmission studies using animal models, including transgenic mice that express human prion protein, have suggested existence of a strong species barrier between cervid CWD and humans. In the current study, we tested CWD transmission into two additional strains of transgenic mice (tg66 and tgRM). These mice over-express human prion protein at high levels and are highly sensitive to infection by human-tropic prions. One hundred and eight mice were inoculated intracerebrally with three different sources of CWD. After long periods of observation, brain tissues from CWD-inoculated mice were screened for evidence of prion infection by RT-QuIC, immunohistochemistry (IHC) and immunoblot. No IHC or immunoblot evidence was found to suggest transmission had occurred, and most mice were negative by RT-QuIC assay. However, four mice with inconsistent positive RT-QuIC reactions were detected. The seeding activity detected in these mice may represent a low level of CWD agent, suggesting a possible transfer of CWD infection. Alternatively, these results might be due to false positive reactions or residual CWD inoculum.

Background: The novel SARS-CoV-2 vaccines partially exploit intrinsic DNA or RNA adjuvanticity, with dysregulation in the metabolism of both these nucleic acids independently linked to triggering experimental autoimmune diseases, including lupus and myositis. Methods: Herein, we present 15 new onset autoimmune myositis temporally associated with SARS-CoV-2 RNA or DNA-based vaccines that occurred between February 2021 and April 2022. Musculoskeletal, pulmonary, cutaneous and cardiac manifestations, laboratory and imaging data were collected. Results: In total, 15 cases of new onset myositis (11 polymyositis/necrotizing/overlap myositis; 4 dermatomyositis) were identified in the Yorkshire region of approximately 5.6 million people, between February 2021 and April 2022 (10 females/5 men; mean age was 66.1 years; range 37–83). New onset disease occurred after first vaccination (5 cases), second vaccination (7 cases) or after the third dose (3 cases), which was often a different vaccine. Of the cases, 6 had systemic complications including skin (3 cases), lung (3 cases), heart (2 cases) and 10/15 had myositis associated autoantibodies. All but 1 case had good therapy responses. Adverse event following immunization (AEFI) could not be explained based on the underlying disease/co-morbidities. Conclusion: Compared with our usual regional Rheumatology clinical experience, a surprisingly large number of new onset myositis cases presented during the period of observation. Given that antigen release inevitably follows muscle injury and given the role of nucleic acid adjuvanticity in autoimmunity and muscle disease, further longitudinal studies are required to explore potential links between novel coronavirus vaccines and myositis in comparison with more traditional vaccine methods.

Prion diseases are progressive, neurodegenerative diseases affecting humans and animals. Also known as the transmissible spongiform encephalopathies, for the hallmark spongiform change seen in the brain, these diseases manifest increased oxidative damage early in disease and changes in antioxidant enzymes in terminal brain tissue. Superoxide dismutase 2 (SOD2) is an antioxidant enzyme that is critical for life. SOD2 knock-out mice can only be kept alive for several weeks post-birth and only with antioxidant therapy. However, this results in the development of a spongiform encephalopathy. Consequently, we hypothesized that reduced levels of SOD2 may accelerate prion disease progression and play a critical role in the formation of spongiform change. Using SOD2 heterozygous knock-out and litter mate wild-type controls, we examined neuronal long-term potentiation, disease duration, pathology, and degree of spongiform change in mice infected with three strains of mouse adapted scrapie. No influence of the reduced SOD2 expression was observed in any parameter measured for any strain. We conclude that changes relating to SOD2 during prion disease are most likely secondary to the disease processes causing toxicity and do not influence the development of spongiform pathology.

Tau aggregates consisting of hyperphosphorylated tau fibrils are associated with many neurodegenerative diseases, including Alzheimer's disease, Pick's disease, frontotemporal dementia, and progressive supranuclear palsy. Tau may contribute to the pathogenesis of these diseases, collectively referred to as tauopathies. In human genetic prion diseases, tau aggregates are detected in association with amyloid plaques consisting of prion protein (PrP). However, the role of abnormal tau aggregates in PrP amyloid disease remains unclear. Previously we inoculated scrapie prions into transgenic mice expressing human tau, mouse tau, glycophosphatidylinositol (GPI) anchored PrP, and anchorless PrP. These mice developed both spongiform vacuolar pathology and PrP amyloid pathology, and human tau was detected near PrP amyloid plaques. However, the presence of human tau did not alter the disease tempo or prion-induced neuropathology. In the present study, we tested mice which more closely modeled familial human prion disease. These mice expressed human tau but lacked both mouse tau and GPI-anchored PrP. However, they did produce anchorless PrP, resulting in perivascular PrP amyloid plaques, i.e. cerebral amyloid angiopathy (CAA), without spongiform degeneration. Typical of PrP amyloid disease, the clinical course was very slow in this model. Nevertheless, the accumulation of aggregated, phosphorylated human tau and its association with PrP amyloid plaques failed to alter the timing or course of the clinical disease observed. These data suggest that human tau does not contribute to the pathogenesis of mouse PrP amyloid brain disease and raise the possibility that tau may also not be pathogenic in human PrP amyloid disease.

ABSTRACT The incidence of locally acquired dengue infections increased during the last decade in the United States, compelling a sustained research effort concerning the dengue mosquito vector, Aedes aegypti, and its microbiome, which has been shown to influence virus transmission success. We examined the “metavirome” of four populations of Aedes aegypti mosquitoes collected in 2016 to 2017 in Manatee County, FL. Unexpectedly, we discovered that dengue virus serotype 4 (DENV4) was circulating in these mosquito populations, representing the first documented case of such a phenomenon in the absence of a local DENV4 human case in this county over a 2-year period. We confirmed that all of the mosquito populations carried the same DENV4 strain, assembled its full genome, validated infection orthogonally by reverse transcriptase PCR, traced the virus origin, estimated the time period of its introduction to the Caribbean region, and explored the viral genetic signatures and mosquito-specific virome associations that potentially mediated DENV4 persistence in mosquitoes. We discuss the significance of prolonged maintenance of the DENV4 infections in A. aegypti that occurred in the absence of a DENV4 human index case in Manatee County with respect to the inability of current surveillance paradigms to detect mosquito vector infections prior to a potential local outbreak. IMPORTANCE Since 1999, dengue outbreaks in the continental United States involving local transmission have occurred only episodically and only in Florida and Texas. In Florida, these episodes appear to be coincident with increased introductions of dengue virus into the region through human travel and migration from countries where the disease is endemic. To date, the U.S. public health response to dengue outbreaks has been largely reactive, and implementation of comprehensive arbovirus surveillance in advance of predictable transmission seasons, which would enable proactive preventative efforts, remains unsupported. The significance of our finding is that it is the first documented report of DENV4 transmission to and maintenance within a local mosquito vector population in the continental United States in the absence of a human case during two consecutive years. Our data suggest that molecular surveillance of mosquito populations in high-risk, high-tourism areas of the United States may enable proactive, targeted vector control before potential arbovirus outbreaks.

Abstract Human familial prion diseases are associated with mutations at 34 different prion protein (PrP) amino acid residues. However, it is unclear whether infectious prions are found in all cases. Mutant PrP itself may be neurotoxic, or alternatively, PrP mutation might predispose to spontaneous formation of infectious PrP isoforms. Previous reports demonstrated transmission to animal models by human brain tissue expressing 7 different PrP mutations, but 3 other mutations were not transmissible. In the present work, we tested transmission using brain homogenates from patients expressing 3 untested PrP mutants: G131V, Y226X, and Q227X. Human brain homogenates were injected intracerebrally into tg66 transgenic mice overexpressing human PrP. Mice were followed for nearly 800 days. From 593 to 762 dpi, 4 of 8 mice injected with Y226X brain had PrPSc detectable in brain by immunostaining, immunoblot, and PrP amyloid seeding activity assayed by RT-QuIC. From 531 to 784 dpi, 11 of 11 G131V-injected mice had PrPSc deposition in brain, but none were positive by immunoblot or RT-QuIC assay. In contrast, from 529 to 798 dpi, no tg66 mice injected with Q227X brain had PrPSc or PrP amyloid seeding activity detectable by these methods. Y226X is the only one of 4 known PrP truncations associated with familial disease which has been shown to be transmissible. This transmission of prion infectivity from a patient expressing truncated human PrP may have implications for the spread and possible transmission of other aggregated truncated proteins in prion-like diseases such as Alzheimer’s disease, Parkinson’s disease and tauopathies.

In prion diseases, the spread of infectious prions (PrPSc) is thought to occur within nerves and across synapses of the central nervous system (CNS). However, the mechanisms by which PrPSc moves within axons and across nerve synapses remain undetermined. Molecular motors, including kinesins and dyneins, transport many types of intracellular cargo. Kinesin-1C (KIF5C) has been shown to transport vesicles carrying the normal prion protein (PrPC) within axons, but whether KIF5C is involved in PrPSc axonal transport is unknown. The current study tested whether stereotactic inoculation in the striatum of KIF5C knock-out mice (Kif5c−/−) with 0.5 µL volumes of mouse-adapted scrapie strains 22 L or ME7 would result in an altered rate of prion spreading and/or disease timing. Groups of mice injected with each strain were euthanized at either pre-clinical time points or following the development of prion disease. Immunohistochemistry for PrP was performed on brain sections and PrPSc distribution and tempo of spread were compared between mouse strains. In these experiments, no differences in PrPSc spread, distribution or survival times were observed between C57BL/6 and Kif5c−/− mice.

Primary immunodeficiencies are heritable disorders of immune function. CD19 is a B cell co-receptor important for B cell development, and CD19 deficiency is a known genetic risk factor for a rare form of primary immunodeficiency known as “common variable immunodeficiency” (CVID); an antibody deficiency resulting in low levels of serum IgG and IgA. Enteropathies are commonly observed in CVID patients but the underlying reason for this is undefined. Here, we utilize CD19−/− mice as a model of CVID to test the hypothesis that antibody deficiency negatively impacts gut physiology under steady-state conditions. As anticipated, immune phenotyping experiments demonstrate that CD19−/− mice develop a severe B cell deficiency in gut-associated lymphoid tissues that result in significant reductions to antibody concentrations in the gut lumen. Antibody deficiency was associated with defective anti-commensal IgA responses and the outgrowth of anaerobic bacteria in the gut. Expansion of anaerobic bacteria coincides with the development of a chronic inflammatory condition in the gut of CD19−/− mice that results in an intestinal malabsorption characterized by defects in lipid metabolism and transport. Administration of the antibiotic metronidazole to target anaerobic members of the microbiota rescues mice from disease indicating that intestinal malabsorption is a microbiota-dependent phenomenon. Finally, intestinal malabsorption in CD19−/− mice is a gluten-sensitive enteropathy as exposure to a gluten-free diet also significantly reduces disease severity in CD19−/− mice. Collectively, these results support an effect of antibody deficiency on steady-state gut physiology that compliment emerging data from human studies linking IgA deficiency with non-infectious complications associated with CVID. They also demonstrate that CD19−/− mice are a useful model for studying the role of B cell deficiency and gut dysbiosis on gluten-sensitive enteropathies; a rapidly emerging group of diseases in humans with an unknown etiology.

Prion protein (PrPC) is a protease-sensitive and soluble cell surface glycoprotein expressed in almost all mammalian cell types. PrPSc, a protease-resistant and insoluble form of PrPC, is the causative agent of prion diseases, fatal and transmissible neurogenerative diseases of mammals. Prion infection is initiated via either ingestion or inoculation of PrPSc or when host PrPC stochastically refolds into PrPSc. In either instance, the early events that occur during prion infection remain poorly understood. We have used transgenic mice expressing mouse PrPC tagged with a unique antibody epitope to monitor the response of host PrPC to prion inoculation. Following intracranial inoculation of either prion-infected or uninfected brain homogenate, we show that host PrPC can accumulate both intra-axonally and within the myelin membrane of axons suggesting that it may play a role in axonal loss following brain injury. Moreover, in response to the inoculation host PrPC exhibits an increased insolubility and protease resistance similar to that of PrPSc, even in the absence of infectious prions. Thus, our results raise the possibility that damage to the brain may be one trigger by which PrPC stochastically refolds into pathogenic PrPSc leading to productive prion infection.

Chronic wasting disease (CWD) is a fatal prion disease that can infect deer, elk and moose. CWD has now been detected in 26 states of the USA, 3 Canadian provinces, South Korea, Norway, Sweden and Finland. CWD continues to spread from endemic areas, and new foci of infections are frequently detected. As increasing numbers of cervids become infected, the likelihood for human exposure increases. To date, no cases of CWD infection in humans have been confirmed, but experience with the BSE zoonosis in the United Kingdom suggests exposure to CWD should be minimized. Specifically, hunters, meat processors and others in contact with tissues from potentially CWD-infected cervids need a practical method to decontaminate knives, saws and other equipment. Prions are notoriously difficult to inactivate, and most effective methods require chemicals or sterilization processes that are either dangerous, caustic, expensive or not readily available. Although corrosive, sodium hypochlorite (bleach) is widely available and affordable and has been shown to inactivate prion agents including those that cause scrapie, bovine spongiform encephalopathy and Creutzfeldt-Jakob disease. In the current study, we confirm that bleach is an effective disinfectant for CWD prions and establish minimum times and bleach concentrations to eliminate prion seeding activity from stainless steel and infected brain homogenate solutions. We found that a five-minute treatment with a 40% dilution of household bleach was effective at inactivating CWD seeding activity from stainless-steel wires and CWD-infected brain homogenates. However, bleach was not able to inactivate CWD seeding activity from solid tissues in our studies.

Neuroinflammation and neurodegeneration are common during prion infection, but the mechanisms that underlie these pathological features are not well understood. Several components of innate immunity, such as Toll-like receptor (TLR) 4 and Complement C1q, have been shown to influence prion disease. To identify additional components of innate immunity that might impact prion disease within the central nervous system (CNS), we screened RNA from brains of pre-clinical and clinical 22L-infected mice for alterations in genes associated with innate immunity. Transcription of several genes encoding damage-associated molecular pattern (DAMP) proteins and receptors were increased in the brains of prion-infected mice. To investigate the role of some of these proteins in prion disease of the CNS, we infected mice deficient in DAMP receptor genes Tlr2, C3ar1, and C5ar1 with 22L scrapie. Elimination of TLR2 accelerated disease by a median of 10 days, while lack of C3aR1 or C5aR1 had no effect on disease tempo. Histopathologically, all knockout mouse strains tested were similar to infected control mice in gliosis, vacuolation, and PrPSc deposition. Analysis of proinflammatory markers in the brains of infected knockout mice indicated only a few alterations in gene expression suggesting that C5aR1 and TLR2 signaling did not act synergistically in the brains of prion-infected mice. These results indicate that signaling through TLR2 confers partial neuroprotection during prion infection.

High myopia increases the risk of blinding eye conditions, so regular follow-up is essential.

The original version of this Article contained errors in the author affiliations. Affiliation 2 incorrectly read ‘Department of Neurology, The First Hospital of Jilin University, Changchun 130021 Jilin Province, China.’Affiliation 5 incorrectly read ‘Department of Otolaryngology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710061 Shanxi Province, China’Affiliation 9 incorrectly read ‘State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.’This has now been corrected in both the PDF and HTML versions of the Article.