PINK1 is a target of T cell responses in Parkinson's disease

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Abstract

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder. While there is no curative treatment, the immune system's involvement with autoimmune T cells that recognize the protein alpha-synuclein (α-syn) in a subset of individuals suggests new areas for therapeutic strategies. As not all patients with PD have T cells specific for α-syn, we explored additional autoantigenic targets of T cells in PD. We generated 15-mer peptides spanning several PD-related proteins implicated in PD pathology, including Glucosylceramidase Beta 1 (GBA), Superoxide dismutase 1 (SOD1), PTEN Induced Kinase 1 (PINK1), Parkin RBR E3 Ubiquitin Protein Ligase (parkin), Oxoglutarate Dehydrogenase (OGDH), and Leucine Rich Repeat Kinase 2 (LRRK2). Cytokine production (IFNγ, IL-5, IL-10) against these proteins was measured using a fluorospot assay and PBMCs from patients with PD and age-matched healthy controls. We identified PINK1, a regulator of mitochondrial stability, as an autoantigen targeted by T cells, as well as its unique epitopes, and their HLA restriction. The PINK1-specific T cell reactivity revealed sex-based differences as it was predominantly found in male patients with PD, which may contribute to the heterogeneity of PD. Identifying and characterizing PINK1 and other autoinflammatory targets may lead to antigen-specific diagnostics, progression markers, and/or novel therapeutic strategies for PD.

Authors

Gregory P. Williams, Antoine Freuchet, Tanner Michaelis, April Frazier, Ngan K. Tran, João Rodrigues Lima-Junior, Elizabeth J. Phillips, Simon A. Mallal, Irene Litvan, Jennifer G. Goldman, Roy N. Alcalay, John Sidney, David Sulzer, Alessandro Sette, Cecilia S. Lindestam Arlehamn

Intestinal Cyp24a1 regulates vitamin D locally independent of systemic regulation by renal Cyp24a1 in mice

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Abstract

Vitamin D regulates mineral homeostasis. The most biologically active form of vitamin D, 1,25-dihydroxyvitamin D (1,25D), is synthesized by CYP27B1 from 25-dihydroxyvitamin D (25D) and inactivated by CYP24A1. Human monogenic diseases and genome-wide association studies support a critical role for CYP24A1 in regulation of mineral homeostasis, but little is known about its tissue-specific effects. Here, we describe the responses of mice with inducible global deletion, kidney-specific, and intestine-specific deletion of Cyp24a1 to dietary calcium challenge and chronic kidney disease (CKD). Global and kidney-specific Cyp24a1 deletion caused similar syndromes of systemic vitamin D intoxication: elevated circulating 1,25D, 25D and fibroblast growth factor 23 (FGF23), activation of vitamin D target genes in the kidney and intestine, hypercalcemia, and suppressed parathyroid hormone (PTH). In contrast, mice with intestine-specific Cyp24a1 deletion demonstrated activation of vitamin D target genes exclusively in the intestine despite no changes in systemic vitamin D levels. In response to a high calcium diet, PTH was suppressed despite normal serum calcium. In mice with CKD, intestinal Cyp24a1 deletion decreased PTH and FGF23 without precipitating hypercalcemia. These results implicate kidney CYP24A1 in systemic vitamin D regulation while independent local effects of intestinal CYP24A1 could be targeted to treat secondary hyperparathyroidism in CKD.

Authors

Michaela A.A. Fuchs, Alexander Grabner, Melody Shi, Susan L. Murray, Emily J. Burke, Nejla Latic, Venkataramana Thiriveedi, Jatin Roper, Shintaro Ide, Koki Abe, Hiroki Kitai, Tomokazu Souma, Myles Wolf

Long COVID is associated with lower percentages of mature, cytotoxic NK cell phenotypes

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Authors

Tasha Tsao, Amanda M. Buck, Lilian Grimbert, Brian H. LaFranchi, Belen Altamirano Poblano, Emily A. Fehrman, Thomas Dalhuisen, Priscilla Y. Hsue, J. Daniel Kelly, Jeffrey N. Martin, Steven G. Deeks, Peter W. Hunt, Michael J. Peluso, Oscar A. Aguilar, Timothy J. Henrich

Regulation of sarcomere formation and function in the healthy heart requires a titin intronic enhancer

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Abstract

Heterozygous truncating variants in the sarcomere protein titin (TTN) are the most common genetic cause of heart failure. To understand mechanisms that regulate abundant cardiomyocyte TTN expression we characterized highly conserved intron 1 sequences that exhibited dynamic changes in chromatin accessibility during differentiation of human cardiomyocytes from induced pluripotent stem cells (hiPSC-CMs). Homozygous deletion of these sequences in mice caused embryonic lethality while heterozygous mice demonstrated allele-specific reduction in Ttn expression. A 296 bp fragment of this element, denoted E1, was sufficient to drive expression of a reporter gene in hiPSC-CMs. Deletion of E1 downregulated TTN expression, impaired sarcomerogenesis, and decreased contractility in hiPSC-CMs. Site-directed mutagenesis of predicted NKX2-5- and MEF2-binding sites within E1 abolished its transcriptional activity. Embryonic mice expressing E1 reporter gene constructs validated in vivo cardiac-specific activity of E1 and the requirement for NKX2-5 and MEF2 binding sequences. Moreover, isogenic hiPSC-CMs containing a rare E1 variant in the predicted MEF2 binding motif that was identified in a patient with unexplained DCM showed reduced TTN expression. Together these discoveries define an essential, functional enhancer that regulates TTN expression. Manipulation of this element may advance therapeutic strategies to treat DCM caused by TTN haploinsufficiency.

Authors

Yuri Kim, Seong Won Kim, David Saul, Meraj Neyazi, Manuel Schmid, Hiroko Wakimoto, Neil Slaven, Joshua H. Lee, Olivia G. Layton, Lauren K. Wasson, Justin H. Letendre, Feng Xiao, Jourdan K. Ewoldt, Konstantinos Gkatzis, Peter Sommer, Bénédicte Gobert, Nicolas Wiest-Daesslé, Quentin McAfee, Nandita Singhal, Mingyue Lun, Joshua M. Gorham, Zoltan Arany, Arun Sharma, Christopher N. Toepfer, Gavin Y. Oudit, William T. Pu, Diane E. Dickel, Len A. Pennacchio, Axel Visel, Christopher S. Chen, J.G. Seidman, Christine E. Seidman

A deep intronic mutation causes RAD50 deficiency through an unusual mechanism of distant exon activation

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Authors

Kristine Bousset, Stefano Donega, Najim Ameziane, Tabea Fleischhammer, Dhanya Ramachandran, Miriam Poley-Gil, Detlev Schindler, Ingrid M. van de Laar, Franco Pagani, Thilo Dörk

Estimation of prevalence of autoimmune diseases in the United States using electronic health record data

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BACKGROUND. Previous epidemiologic studies of autoimmune diseases in the United States (US) have included a limited number of diseases or used meta-analyses that rely on different data collection methods and analyses for each disease. METHODS. To estimate the prevalence of autoimmune diseases in the US, we used electronic health record data from six large medical systems in the US. We developed a software program using common methodology to compute the estimated prevalence of autoimmune diseases alone and in aggregate that can be readily used by other investigators to replicate or modify the analysis over time. RESULTS. Our findings indicate that over 15 million people, or 4.6% of the US population, have been diagnosed with at least one autoimmune disease from January 1, 2011, to June 1, 2022, and 34% of those are diagnosed with more than one autoimmune disease. As expected, females (63% of those with autoimmune disease) were almost twice as likely as males to be diagnosed with an autoimmune disease. We identified the top 20 autoimmune diseases based on prevalence and according to sex and age. CONCLUSION. Thus, we provide, for the first time, a large-scale prevalence estimate of autoimmune disease in the US by sex and age. FUNDING. Autoimmune Registry Inc., the National Heart Lung and Blood Institute, the National Center for Advancing Translational Sciences, the Intramural Research Program of the National Institute of Environmental Health Sciences.

Authors

Aaron H. Abend, Ingrid He, Neil Bahroos, Stratos Christianakis, Ashley B. Crew, Leanna M. Wise, Gloria P. Lipori, Xing He, Shawn N. Murphy, Christopher D. Herrick, Jagannadha Avasarala, Mark G. Weiner, Jacob S. Zelko, Erica Matute-Arcos, Mark Abajian, Philip R.O. Payne, Albert M. Lai, Heath A. Davis, Asher A. Hoberg, Chris E. Ortman, Amit D. Gode, Bradley W. Taylor, Kristen I. Osinski, Damian N. Di Florio, Noel R. Rose, Frederick W. Miller, George C. Tsokos, DeLisa Fairweather

Red Blood Cells Capture and Deliver Bacterial DNA to Drive Host Responses During Polymicrobial Sepsis

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Red blood cells (RBCs), traditionally recognized for their role in transporting oxygen, play a pivotal role in the body's immune response by expressing TLR9 and scavenging excess host cell-free DNA. DNA capture by RBCs leads to accelerated RBC clearance and triggers inflammation. Whether RBCs can also acquire microbial DNA during infections is unknown. Murine RBCs acquire microbial DNA in vitro and bacterial-DNA-induced macrophage activation was augmented by WT but not Tlr9-deleted RBCs. In a mouse model of polymicrobial sepsis, RBC-bound bacterial DNA was elevated in WT but not in erythroid Tlr9-deleted mice. Plasma cytokine analysis in these mice revealed distinct sepsis clusters characterized by persistent hypothermia and hyperinflammation in the most severely affected subjects. RBC-Tlr9 deletion attenuated plasma and tissue IL-6 production in the most severe group. Parallel findings in human subjects confirmed that RBCs from septic patients harbored more bacterial DNA compared to healthy individuals. Further analysis through 16S sequencing of RBC-bound DNA illustrated distinct microbial communities, with RBC-bound DNA composition correlating with plasma IL-6 in patients with sepsis. Collectively, these findings unveil RBCs as overlooked reservoirs and couriers of microbial DNA, capable of influencing host inflammatory responses in sepsis.

Authors

LK Metthew Lam, Nathan J. Klingensmith, Layal Sayegh, Emily Oatman, Joshua S. Jose, Christopher V. Cosgriff, Kaitlyn A. Eckart, John McGinnis, Piyush Ranjan, Matthew Lanza, Nadir Yehya, Nuala J. Meyer, Robert P. Dickson, Nilam S. Mangalmurti

Clinical tolerance but no protective efficacy in a placebo-controlled trial of repeated controlled schistosome infection

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BACKGROUND. Partial protective immunity to schistosomiasis develops over time, following repeated praziquantel treatment. Moreover, animals develop protective immunity after repeated immunisation with irradiated cercariae. Here, we evaluated development of natural immunity through consecutive exposure-treatment cycles with Schistosoma mansoni (Sm) in healthy, Schistosoma-naïve participants using single-sex controlled human Sm infection. METHODS. Twenty-four participants were randomised double-blind (1:1) to either the reinfection group, which received three exposures (week 0,9,18) to 20 male cercariae or the infection control group, which received two mock exposures with water (week 0,9) prior to cercariae exposure (week 18). Participants were treated with praziquantel (or placebo) at week 8, 17 and 30. Attack rates after the final exposure (week 19-30) using serum circulating anodic antigen (CAA) positivity were compared between groups. Adverse events were collected for safety. RESULTS. Twenty-three participants completed follow-up. No protective efficacy was seen, given 82% (9/11) attack rate after the final exposure in the reinfection group and 92% (11/12) in the infection control group (protective efficacy 11%; 95% CI -24% to 35%; p =0.5). Related adverse events were higher after the first infection (45%), compared to the second (27%) and third infection (28%). Severe acute schistosomiasis was observed after the first infections only (2/12 in reinfection group and 2/12 in infection control group). CONCLUSION. Repeated Schistosoma exposure and treatment cycles resulted in apparent clinical tolerance, with fewer symptoms reported with subsequent infections, but did not result in protection against reinfection. TRIAL REGISTRATION. ClinicalTrials.gov NCT05085470. FUNDING. ERC Starting grant (no. 101075876).

Authors

Jan Pieter R. Koopman, Emma L. Houlder, Jacqueline J. Janse, Olivia A.C. Lamers, Geert V.T. Roozen, Jeroen C. Sijtsma, Miriam Casacuberta-Partal, Stan T. Hilt, M.Y. Eileen C. van der Stoep, Inge M. van Amerongen-Westra, Eric A.T. Brienen, Linda J. Wammes, Lisette van Lieshout, Govert J. van Dam, Paul L.A.M. Corstjens, Angela van Diepen, Maria Yazdanbakhsh, Cornelis H. Hokke, Meta Roestenberg

Senescence of endothelial cells increases susceptibility to Kaposi's sarcoma-associated herpesvirus infection via CD109-mediated viral entry

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Abstract

The aging process is characterized by cellular functional decline and increased susceptibility to infections. Understanding the association between virus infection and aging is crucial for developing effective strategies against viral infections in older individuals. However, the relationship between Kaposi's sarcoma-associated herpesvirus (KSHV) infection, a cause of Kaposi's sarcoma prevalent among the elderly without HIV infection, and cellular senescence remains enigmatic. This study uncovers a fascinating link between cellular senescence and enhanced KSHV infectivity in human endothelial cells. Through a comprehensive proteomic analysis, we identified caveolin-1 and CD109 as novel host factors significantly upregulated in senescent cells that promote KSHV infection. Remarkably, CRISPR-Cas9-mediated knockout of these factors reduced KSHV binding and entry, leading to decreased viral infectivity. Furthermore, surface plasmon resonance analysis and confocal microscopy revealed a direct interaction between KSHV virions and CD109 on the cell surface during entry, with recombinant CD109 protein exhibiting an intriguing ability to inhibit infection by blocking virion binding. These findings uncover a previously unrecognized role of cellular senescence in enhancing KSHV infection through upregulation of specific host factors and provide novel insights into the complex interplay between aging and viral pathogenesis.

Authors

Myung-Ju Lee, Jun-Hee Yeon, Jisu Lee, Yun Hee Kang, Beom Seok Park, Joo Hee Park, Sung-Ho Yun, Dagmar Wirth, Seung-Min Yoo, Changhoon Park, Shou-Jiang Gao, Myung-Shin Lee

MicroRNAs: Where brilliance, perseverance, and ambition converged

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Authors

Rares Drula, George A. Calin