Issue published January 2, 2024 Previous issue | Next issue
On the cover: Immune activation following AAV administration
Salabarria et al. demonstrate the kinetics of complement activation following adeno-associated viral (AAV) gene therapy in human subjects and show improvements in safety when AAV is administered with immunosuppression regimens. The cover art depicts red blood cells, lymphocytes, neutrophils, macrophages, and platelets flowing through the bloodstream alongside AAV particles. The AAV particles trigger the innate immune system, as illustrated by activated platelets, blood clot formation, and fragmented red blood cells (schistocytes) in the foreground. Image credit: Stephanie Salabarria.
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AAP Presidential Address
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Abstract
Authors
Daniel P. Kelly
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APSA Presidential Address
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Yentli E. Soto Albrecht
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Reviews
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Abstract
Following a period of slow progress, the completion of genome sequencing and the paradigm shift relative to the cell of origin for high grade serous ovarian cancer (HGSOC) led to a new perspective on the biology and therapeutic solutions for this deadly cancer. Experimental models were revisited to address old questions, and improved tools were generated. Additional pathways emerging as drivers of ovarian tumorigenesis and key dependencies for therapeutic targeting, in particular, VEGF-driven angiogenesis and homologous recombination deficiency, were discovered. Molecular profiling of histological subtypes of ovarian cancer defined distinct genetic events for each entity, enabling the first attempts toward personalized treatment. Armed with this knowledge, HGSOC treatment was revised to include new agents. Among them, PARP inhibitors (PARPis) were shown to induce unprecedented improvement in clinical benefit for selected subsets of patients. Research on mechanisms of resistance to PARPis is beginning to discover vulnerabilities and point to new treatment possibilities. This Review highlights these advances, the remaining challenges, and unsolved problems in the field.
Authors
Yinu Wang, Alexander James Duval, Mazhar Adli, Daniela Matei
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Sarcoidosis is a complex immune-mediated disease characterized by clusters of immune cells called granulomas. Despite major steps in understanding the cause of this disease, many questions remain. In this Review, we perform a mechanistic interrogation of the immune activities that contribute to granuloma formation in sarcoidosis and compare these processes with its closest mimic, tuberculosis, highlighting shared and divergent immune activities. We examine how Mycobacterium tuberculosis is sensed by the immune system; how the granuloma is initiated, formed, and perpetuated in tuberculosis compared with sarcoidosis; and the role of major innate and adaptive immune cells in shaping these processes. Finally, we draw these findings together around several recent high-resolution studies of the granuloma in situ that utilized the latest advances in single-cell technology combined with spatial methods to analyze plausible disease mechanisms. We conclude with an overall view of granuloma formation in sarcoidosis.
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Praveen Weeratunga, David R. Moller, Ling-Pei Ho
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The concept of induced protein degradation by small molecules has emerged as a promising therapeutic strategy that is particularly effective in targeting proteins previously considered “undruggable.” Thalidomide analogs, employed in the treatment of multiple myeloma, stand as prime examples. These compounds serve as molecular glues, redirecting the CRBN E3 ubiquitin ligase to degrade myeloma-dependency factors, IKZF1 and IKZF3. The clinical success of thalidomide analogs demonstrates the therapeutic potential of induced protein degradation. Beyond molecular glue degraders, several additional modalities to trigger protein degradation have been developed and are currently under clinical evaluation. These include heterobifunctional degraders, polymerization-induced degradation, ligand-dependent degradation of nuclear hormone receptors, disruption of protein interactions, and various other strategies. In this Review, we will provide a concise overview of various degradation modalities, their clinical applications, and potential future directions in the field of protein degradation.
Authors
Hojong Yoon, Justine C. Rutter, Yen-Der Li, Benjamin L. Ebert
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Commentaries
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Early identification of neurodegenerative diseases before extensive neuronal loss or disabling symptoms have occurred is imperative for effective use of disease-modifying therapies. Emerging data indicate that central Lewy body diseases — Parkinson disease and dementia with Lewy bodies — can begin in the peripheral nervous system, opening up a therapeutic window before central involvement. In this issue of the JCI, Goldstein et al. report that cardiac 18F-dopamine positron emission tomography reveals lower activity selectively in individuals with several self-reported Parkinson disease risk factors who later develop Parkinson disease or dementia with Lewy bodies. Accurately identifying which at-risk individuals will develop central Lewy body disease will optimize early patient selection for disease-modifying therapies.
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Anna E. Goodheart, Craig Blackstone
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Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder caused by an unstable expanded CTG repeat located in the 3′-UTR of the DM1 protein kinase (DMPK) gene. The pathogenic mechanism results in misregulated alternative splicing of hundreds of genes, creating the dilemma of establishing which genes contribute to the mechanism of DM1 skeletal muscle pathology. In this issue of the JCI, Cisco and colleagues systematically tested the combinatorial effects of DM1-relevant mis-splicing patterns in vivo and identified the synergistic effects of mis-spliced calcium and chloride channels as a major contributor to DM1 skeletal muscle impairment. The authors further demonstrated the therapeutic potential for calcium channel modulation to block the synergistic effects and rescue myopathy.
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Larissa Nitschke, Thomas A. Cooper
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The ability to change an organism’s DNA through gene editing is of great importance for the prevention and treatment of genetic and acquired diseases. Rapid progress has been made during the last decade due to the discovery and refinement of CRISPR/Cas9 as an accurate, fast, and reliable genome editing technique. In this issue of the JCI, Lebek et al. present the culmination from a line of work in the Olson laboratory focused on in vivo gene editing of CAMK2D. The paper presents a combined state-of-the-art gene therapy approach that demonstrates how gene therapy can yield cardioprotection in a mouse model and takes notable steps toward potential applicability in patients.
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John E. Smith III, Henk Granzier
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Research Letters
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Feng Pan, Jolanda Sarno, Johan Jeong, Xin Yang, Astraea Jager, Tanja A. Gruber, Kara L. Davis, Michael L. Cleary
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Garth T. Whiteside, Donald J. Kyle, Ram P. Kapil, Alessandra Cipriano, Ellie He, Mingyan Zhou, Manjunath S. Shet, Michele Hummel, Terri Knappenberger, Kazuya Fukumura, Yoshiyuki Matsuo, Masahiro Uehira, Shuichi Hiroyama, Nozomi Takai, Sandra K. Willsie, Stephen C. Harris
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Research Articles
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Abstract
Mineralocorticoid excess commonly leads to hypertension (HTN) and kidney disease. In our study, we used single-cell expression and chromatin accessibility tools to characterize the mineralocorticoid target genes and cell types. We demonstrated that mineralocorticoid effects were established through open chromatin and target gene expression, primarily in principal and connecting tubule cells and, to a lesser extent, in segments of the distal convoluted tubule cells. We examined the kidney-protective effects of steroidal and nonsteroidal mineralocorticoid antagonists (MRAs), as well as of amiloride, an epithelial sodium channel inhibitor, in a rat model of deoxycorticosterone acetate, unilateral nephrectomy, and high-salt consumption–induced HTN and cardiorenal damage. All antihypertensive therapies protected against cardiorenal damage. However, finerenone was particularly effective in reducing albuminuria and improving gene expression changes in podocytes and proximal tubule cells, even with an equivalent reduction in blood pressure. We noted a strong correlation between the accumulation of injured/profibrotic tubule cells expressing secreted posphoprotein 1 (Spp1), Il34, and platelet-derived growth factor subunit b (Pdgfb) and the degree of fibrosis in rat kidneys. This gene signature also showed a potential for classifying human kidney samples. Our multiomics approach provides fresh insights into the possible mechanisms underlying HTN-associated kidney disease, the target cell types, the protective effects of steroidal and nonsteroidal MRAs, and amiloride.
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Amin Abedini, Andrea Sánchez-Navaro, Junnan Wu, Konstantin A. Klötzer, Ziyuan Ma, Bibek Poudel, Tomohito Doke, Michael S. Balzer, Julia Frederick, Hana Cernecka, Hongbo Liu, Xiujie Liang, Steven Vitale, Peter Kolkhof, Katalin Susztak
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Physiologic activation of estrogen receptor α (ERα) is mediated by estradiol (E2) binding in the ligand-binding pocket of the receptor, repositioning helix 12 (H12) to facilitate binding of coactivator proteins in the unoccupied coactivator binding groove. In breast cancer, activation of ERα is often observed through point mutations that lead to the same H12 repositioning in the absence of E2. Through expanded genetic sequencing of breast cancer patients, we identified a collection of mutations located far from H12 but nonetheless capable of promoting E2-independent transcription and breast cancer cell growth. Using machine learning and computational structure analyses, this set of mutants was inferred to act distinctly from the H12-repositioning mutants and instead was associated with conformational changes across the ERα dimer interface. Through both in vitro and in-cell assays of full-length ERα protein and isolated ligand-binding domain, we found that these mutants promoted ERα dimerization, stability, and nuclear localization. Point mutations that selectively disrupted dimerization abrogated E2-independent transcriptional activity of these dimer-promoting mutants. The results reveal a distinct mechanism for activation of ERα function through enforced receptor dimerization and suggest dimer disruption as a potential therapeutic strategy to treat ER-dependent cancers.
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Seema Irani, Wuwei Tan, Qing Li, Weiyi Toy, Catherine Jones, Mayur Gadiya, Antonio Marra, John A. Katzenellenbogen, Kathryn E. Carlson, Benita S. Katzenellenbogen, Mostafa Karimi, Ramya Segu Rajappachetty, Isabella S. Del Priore, Jorge S. Reis-Filho, Yang Shen, Sarat Chandarlapaty
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ASXL1 mutation frequently occurs in all forms of myeloid malignancies and is associated with aggressive disease and poor prognosis. ASXL1 recruits Polycomb repressive complex 2 (PRC2) to specific gene loci to repress transcription through trimethylation of histone H3 on lysine 27 (H3K27me3). ASXL1 alterations reduce H3K27me3 levels, which results in leukemogenic gene expression and the development of myeloid malignancies. Standard therapies for myeloid malignancies have limited efficacy when mutated ASXL1 is present. We discovered upregulation of lysine demethylase 6B (KDM6B), a demethylase for H3K27me3, in ASXL1-mutant leukemic cells, which further reduces H3K27me3 levels and facilitates myeloid transformation. Here, we demonstrated that heterozygous deletion of Kdm6b restored H3K27me3 levels and normalized dysregulated gene expression in Asxl1Y588XTg hematopoietic stem/progenitor cells (HSPCs). Furthermore, heterozygous deletion of Kdm6b decreased the HSPC pool, restored their self-renewal capacity, prevented biased myeloid differentiation, and abrogated progression to myeloid malignancies in Asxl1Y588XTg mice. Importantly, administration of GSK-J4, a KDM6B inhibitor, not only restored H3K27me3 levels but also reduced the disease burden in NSG mice xenografted with human ASXL1-mutant leukemic cells in vivo. This preclinical finding provides compelling evidence that targeting KDM6B may be a therapeutic strategy for myeloid malignancies with ASXL1 mutations.
Authors
Guo Ge, Peng Zhang, Pinpin Sui, Shi Chen, Hui Yang, Ying Guo, Ivan P. Rubalcava, Asra Noor, Caroline R. Delma, Joel Agosto-Peña, Hui Geng, Edward A. Medina, Ying Liang, Stephen D. Nimer, Ruben Mesa, Omar Abdel-Wahab, Mingjiang Xu, Feng-Chun Yang
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Hormone receptor–positive breast cancer (HR+) is immunologically cold and has not benefited from advances in immunotherapy. In contrast, subsets of triple-negative breast cancer (TNBC) display high leukocytic infiltration and respond to checkpoint blockade. CD8+ T cells, the main effectors of anticancer responses, recognize MHC I–associated peptides (MAPs). Our work aimed to characterize the repertoire of MAPs presented by HR+ and TNBC tumors. Using mass spectrometry, we identified 57,094 unique MAPs in 26 primary breast cancer samples. MAP source genes highly overlapped between both subtypes. We identified 25 tumor-specific antigens (TSAs) mainly deriving from aberrantly expressed regions. TSAs were most frequently identified in TNBC samples and were more shared among The Cancer Genome Atlas (TCGA) database TNBC than HR+ samples. In the TNBC cohort, the predicted number of TSAs positively correlated with leukocytic infiltration and overall survival, supporting their immunogenicity in vivo. We detected 49 tumor-associated antigens (TAAs), some of which derived from cancer-associated fibroblasts. Functional expansion of specific T cell assays confirmed the in vitro immunogenicity of several TSAs and TAAs. Our study identified attractive targets for cancer immunotherapy in both breast cancer subtypes. The higher prevalence of TSAs in TNBC tumors provides a rationale for their responsiveness to checkpoint blockade.
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Eralda Kina, Jean-Philippe Laverdure, Chantal Durette, Joël Lanoix, Mathieu Courcelles, Qingchuan Zhao, Anca Apavaloaei, Jean-David Larouche, Marie-Pierre Hardy, Krystel Vincent, Patrick Gendron, Leslie Hesnard, Catherine Thériault, Maria Virginia Ruiz Cuevas, Grégory Ehx, Pierre Thibault, Claude Perreault
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Several poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are approved by FDA to treat cancer with BRCA mutations. BRCA mutations are considered to fuel a PARPi killing effect by inducing apoptosis. However, resistance to PARPi is frequently observed in the clinic due to an incomplete understanding on the molecular basis of PARPi function and a lack of good markers, beyond BRCA mutations, to predict response. Here, we show that gasdermin C (GSDMC) sensitized tumor cells to PARPi in vitro and in immunocompetent mice and caused durable tumor regression in an immune-dependent manner. A high expression level of GSDMC predicted better response to PARPi treatment in patients with triple-negative breast cancer (TNBC). PARPi treatment triggered GSDMC/caspase-8–mediated cancer cell pyroptosis (CCP) that enhanced PARPi killing of tumor cells. GSDMC-mediated CCP increased memory CD8+ T cell population in lymph node (LN), spleen, and tumor and, thus, promoted cytotoxic CD8+ T cell infiltration in the tumor microenvironment. T cell–derived granzyme B (GZMB) activated caspase-6, which subsequently cleaved GSDMC to induce pyroptosis. Interestingly, IFN-γ induced GSDMC expression, which, in turn, enhanced the cytotoxicity of PARPi and T cells. Importantly, GSDMC promoted tumor clearance independent of BRCA deficiency in multiple cancer types with PARPi treatment. This study identifies a general marker and target for PARPi therapy and offers insights into the mechanism of PARPi function.
Authors
Shuanglian Wang, Chiung-Wen Chang, Juan Huang, Shan Zeng, Xin Zhang, Mien-Chie Hung, Junwei Hou
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Virophagy, the selective autophagosomal engulfment and lysosomal degradation of viral components, is crucial for neuronal cell survival and antiviral immunity. However, the mechanisms leading to viral antigen recognition and capture by autophagic machinery remain poorly understood. Here, we identified cyclin-dependent kinase–like 5 (CDKL5), known to function in neurodevelopment, as an essential regulator of virophagy. Loss-of-function mutations in CDKL5 are associated with a severe neurodevelopmental encephalopathy. We found that deletion of CDKL5 or expression of a clinically relevant pathogenic mutant of CDKL5 reduced virophagy of Sindbis virus (SINV), a neurotropic RNA virus, and increased intracellular accumulation of SINV capsid protein aggregates and cellular cytotoxicity. Cdkl5-knockout mice displayed increased viral antigen accumulation and neuronal cell death after SINV infection and enhanced lethality after infection with several neurotropic viruses. Mechanistic studies demonstrated that CDKL5 directly binds the canonical selective autophagy receptor p62 and phosphorylates p62 at T269/S272 to promote its interaction with viral capsid aggregates. We found that CDKL5-mediated phosphorylation of p62 facilitated the formation of large p62 inclusion bodies that captured viral capsids to initiate capsid targeting to autophagic machinery. Overall, these findings identify a cell-autonomous innate immune mechanism for autophagy activation to clear intracellular toxic viral protein aggregates during infection.
Authors
Josephine W. Thinwa, Zhongju Zou, Emily Parks, Salwa Sebti, Kelvin Hui, Yongjie Wei, Mohammad Goodarzi, Vibha Singh, Greg Urquhart, Jenna L. Jewell, Julie K. Pfeiffer, Beth Levine, Tiffany A. Reese, Michael U. Shiloh
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Although most CD8+ T cells are equipped to kill infected or transformed cells, a subset may regulate immune responses and preserve self-tolerance. Here, we describe a CD8 lineage that is instructed to differentiate into CD8 T regulatory cells (Tregs) by a surprisingly restricted set of T cell receptors (TCRs) that recognize MHC-E (mouse Qa-1) and several dominant self-peptides. Recognition and elimination of pathogenic target cells that express these Qa-1–self-peptide complexes selectively inhibits pathogenic antibody responses without generalized immune suppression. Immunization with synthetic agonist peptides that mobilize CD8 Tregs in vivo efficiently inhibit antigraft antibody responses and markedly prolong heart and kidney organ graft survival. Definition of TCR-dependent differentiation and target recognition by this lineage of CD8 Tregs may open the way to new therapeutic approaches to inhibit pathogenic antibody responses.
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Hye-Jung Kim, Hidetoshi Nakagawa, John Y. Choi, Xuchun Che, Andrew Divris, Qingshi Liu, Andrew E. Wight, Hengcheng Zhang, Anis Saad, Zhabiz Solhjou, Christa Deban, Jamil R. Azzi, Harvey Cantor
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Pre-mRNA splicing is a highly coordinated process. While its dysregulation has been linked to neurological deficits, our understanding of the underlying molecular and cellular mechanisms remains limited. We implicated pathogenic variants in U2AF2 and PRPF19, encoding spliceosome subunits in neurodevelopmental disorders (NDDs), by identifying 46 unrelated individuals with 23 de novo U2AF2 missense variants (including 7 recurrent variants in 30 individuals) and 6 individuals with de novo PRPF19 variants. Eight U2AF2 variants dysregulated splicing of a model substrate. Neuritogenesis was reduced in human neurons differentiated from human pluripotent stem cells carrying two U2AF2 hyper-recurrent variants. Neural loss of function (LoF) of the Drosophila orthologs U2af50 and Prp19 led to lethality, abnormal mushroom body (MB) patterning, and social deficits, which were differentially rescued by wild-type and mutant U2AF2 or PRPF19. Transcriptome profiling revealed splicing substrates or effectors (including Rbfox1, a third splicing factor), which rescued MB defects in U2af50-deficient flies. Upon reanalysis of negative clinical exomes followed by data sharing, we further identified 6 patients with NDD who carried RBFOX1 missense variants which, by in vitro testing, showed LoF. Our study implicates 3 splicing factors as NDD-causative genes and establishes a genetic network with hierarchy underlying human brain development and function.
Authors
Dong Li, Qin Wang, Allan Bayat, Mark R. Battig, Yijing Zhou, Daniëlle G.M. Bosch, Gijs van Haaften, Leslie Granger, Andrea K. Petersen, Luis A. Pérez-Jurado, Gemma Aznar-Laín, Anushree Aneja, Miroslava Hancarova, Sarka Bendova, Martin Schwarz, Radka Kremlikova Pourova, Zdenek Sedlacek, Beth A. Keena, Michael E. March, Cuiping Hou, Nora O’Connor, Elizabeth J. Bhoj, Margaret H. Harr, Gabrielle Lemire, Kym M. Boycott, Meghan Towne, Megan Li, Mark Tarnopolsky, Lauren Brady, Michael J. Parker, Hanna Faghfoury, Lea Kristin Parsley, Emanuele Agolini, Maria Lisa Dentici, Antonio Novelli, Meredith Wright, Rachel Palmquist, Khanh Lai, Marcello Scala, Pasquale Striano, Michele Iacomino, Federico Zara, Annina Cooper, Timothy J. Maarup, Melissa Byler, Robert Roger Lebel, Tugce B. Balci, Raymond Louie, Michael Lyons, Jessica Douglas, Catherine Nowak, Alexandra Afenjar, Juliane Hoyer, Boris Keren, Saskia M. Maas, Mahdi M. Motazacker, Julian A. Martinez-Agosto, Ahna M. Rabani, Elizabeth M. McCormick, Marni J. Falk, Sarah M. Ruggiero, Ingo Helbig, Rikke S. Møller, Lino Tessarollo, Francesco Tomassoni Ardori, Mary Ellen Palko, Tzung-Chien Hsieh, Peter M. Krawitz, Mythily Ganapathi, Bruce D. Gelb, Vaidehi Jobanputra, Ashley Wilson, John Greally, Sébastien Jacquemont, Khadijé Jizi, Ange-Line Bruel, Chloé Quelin, Vinod K. Misra, Erika Chick, Corrado Romano, Donatella Greco, Alessia Arena, Manuela Morleo, Vincenzo Nigro, Rie Seyama, Yuri Uchiyama, Naomichi Matsumoto, Ryoji Taira, Katsuya Tashiro, Yasunari Sakai, Gökhan Yigit, Bernd Wollnik, Michael Wagner, Barbara Kutsche, Anna C.E. Hurst, Michelle L. Thompson, Ryan Schmidt, Linda Randolph, Rebecca C. Spillmann, Vandana Shashi, Edward J. Higginbotham, Dawn Cordeiro, Amanda Carnevale, Gregory Costain, Tayyaba Khan, Benoît Funalot, Frederic Tran Mau-Them, Luis Fernandez Garcia Moya, Sixto García-Miñaúr, Matthew Osmond, Lauren Chad, Nada Quercia, Diana Carrasco, Chumei Li, Amarilis Sanchez-Valle, Meghan Kelley, Mathilde Nizon, Brynjar O. Jensson, Patrick Sulem, Kari Stefansson, Svetlana Gorokhova, Tiffany Busa, Marlène Rio, Hamza Hadj Habdallah, Marion Lesieur-Sebellin, Jeanne Amiel, Véronique Pingault, Sandra Mercier, Marie Vincent, Christophe Philippe, Clemence Fatus-Fauconnier, Kathryn Friend, Rebecca K. Halligan, Sunita Biswas, Jane Rosser, Cheryl Shoubridge, Mark Corbett, Christopher Barnett, Jozef Gecz, Kathleen Leppig, Anne Slavotinek, Carlo Marcelis, Rolph Pfundt, Bert B.A. de Vries, Marjon A. van Slegtenhorst, Alice S. Brooks, Benjamin Cogne, Thomas Rambaud, Zeynep Tümer, Elaine H. Zackai, Naiara Akizu, Yuanquan Song, Hakon Hakonarson
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We have previously demonstrated that cystatin E/M (CST6), which is elevated in a subset of patients with multiple myeloma (MM) lacking osteolytic lesions (OLs), suppresses MM bone disease by blocking osteoclast differentiation and function. CST6 is a secreted type 2 cystatin, a cysteine protease inhibitor that regulates lysosomal cysteine proteases and the asparaginyl endopeptidase legumain. Here, we developed B cell maturation antigen (BCMA) CST6 chimeric antigen receptor T cells (CAR-T cells), which lysed MM cells and released CST6 proteins. Our in vitro studies show that these CAR-T cells suppressed the differentiation and formation of tartrate-resistant acid phosphatase–positive (TRAP+) osteoclasts. Using xenografted MM mice, bioluminescence images showed that both BCMA–CAR-T and BCMA–CST6–CAR-T cells inhibited MM growth to a similar extent. Reconstructed micro–computed tomography images revealed that BCMA–CST6–CAR-T cells, but not BCMA–CAR-T cells, prevented MM-induced bone damage and decreased osteoclast numbers. Our results provide a CAR-T strategy that targets tumor cells directly and delivers an inhibitor of bone resorption.
Authors
Fumou Sun, Yan Cheng, Jin-Ran Chen, Visanu Wanchai, David E. Mery, Hongwei Xu, Dongzheng Gai, Samer Al Hadidi, Carolina Schinke, Sharmilan Thanendrarajan, Maurizio Zangari, Frits van Rhee, Guido Tricot, John D. Shaughnessy Jr., Fenghuang Zhan
×Abstract
Even with the prolific clinical use of next-generation cancer therapeutics, many tumors remain unresponsive or become refractory to therapy, creating a medical need. In cancer, DCs are indispensable for T cell activation, so there is a restriction on cytotoxic T cell immunity if DCs are not present in sufficient numbers in the tumor and draining lymph nodes to take up and present relevant cancer antigens. To address this bottleneck, we developed a therapeutic based on albumin fused with FMS-related tyrosine kinase 3 ligand (Alb-Flt3L) that demonstrated superior pharmacokinetic properties compared with Flt3L, including significantly longer half-life, accumulation in tumors and lymph nodes, and cross-presenting-DC expansion following a single injection. We demonstrated that Alb-Flt3L, in combination with standard-of-care chemotherapy and radiation therapy, serves as an in situ vaccination strategy capable of engendering polyclonal tumor neoantigen–specific immunity spontaneously. In addition, Alb-Flt3L–mediated tumor control synergized with immune checkpoint blockade delivered as anti–PD-L1. The mechanism of action of Alb-Flt3L treatment revealed a dependency on Batf3, type I IFNs, and plasmacytoid DCs. Finally, the ability of Alb-Flt3L to expand human DCs was explored in humanized mice. We observed significant expansion of human cross-presenting-DC subsets, supporting the notion that Alb-Flt3L could be used clinically to modulate human DC populations in future cancer therapeutic regimens.
Authors
Brandon Lam, Yu Jui Kung, John Lin, Ssu-Hsueh Tseng, Hsin-Fang Tu, Claire Huang, Brandon Lee, Esteban Velarde, Ya Chea Tsai, Rafael Villasmil, Sung Taek Park, Deyin Xing, Chien-Fu Hung, T.-C. Wu
×Abstract
Mutations in the BRCA2 tumor suppressor gene have been associated with an increased risk of developing prostate cancer. One of the paradoxes concerning BRCA2 is the fact that its inactivation affects genetic stability and is deleterious for cellular and organismal survival, while BRCA2-mutated cancer cells adapt to this detriment and malignantly proliferate. Therapeutic strategies for tumors arising from BRCA2 mutations may be discovered by understanding these adaptive mechanisms. In this study, we conducted forward genetic synthetic viability screenings in Caenorhabditis elegans brc-2 (Cebrc-2) mutants and found that Ceubxn-2 inactivation rescued the viability of Cebrc-2 mutants. Moreover, loss of NSFL1C, the mammalian ortholog of CeUBXN-2, suppressed the spindle assembly checkpoint (SAC) activation and promoted the survival of BRCA2-deficient cells. Mechanistically, NSFL1C recruited USP9X to inhibit the polyubiquitination of AURKB and reduce the removal of AURKB from the centromeres by VCP, which is essential for SAC activation. SAC inactivation is common in BRCA2-deficient prostate cancer patients, but PP2A inhibitors could reactivate the SAC and achieve BRCA2-deficient prostate tumor synthetic lethality. Our research reveals the survival adaptation mechanism of BRCA2-deficient prostate tumor cells and provides different angles for exploring synthetic lethal inhibitors in addition to targeting DNA damage repair pathways.
Authors
Jian Wang, Yuke Chen, Shiwei Li, Wanchang Liu, Xiao Albert Zhou, Yefei Luo, Zhanzhan Xu, Yundong Xiong, Kaiqi Cheng, Mingjian Ruan, Wei Yu, Xiaoman Li, Weibin Wang, Jiadong Wang
×Abstract
BACKGROUND. In Lewy body diseases (LBDs) Parkinson disease (PD), and dementia with Lewy bodies (DLB), by the time parkinsonism or cognitive dysfunction manifests clinically, substantial neurodegeneration has already occurred. Biomarkers are needed to identify central LBDs in a preclinical phase, when neurorescue strategies might forestall symptomatic disease. This phase may involve catecholamine deficiency in the autonomic nervous system. We analyzed data from the prospective, observational, long-term PDRisk study to assess the predictive value of low versus normal cardiac 18F-dopamine positron emission tomography (PET), an index of myocardial content of the sympathetic neurotransmitter norepinephrine, in at-risk individuals. METHODS. Participants self-reported risk factor information (genetics, olfactory dysfunction, dream enactment behavior, and orthostatic intolerance or hypotension) at a protocol-specific website. Thirty-four with 3 or more confirmed risk factors underwent serial cardiac 18F-dopamine PET at 1.5-year intervals for up to 7.5 years or until PD was diagnosed. RESULTS. Nine participants had low initial myocardial 18F-dopamine–derived radioactivity (<6,000 nCi-kg/cc-mCi) and 25 had normal radioactivity. At 7 years of follow-up, 8 of 9 with low initial radioactivity and 1 of 11 with normal radioactivity were diagnosed with a central LBD (LBD+) (P = 0.0009 by Fisher’s exact test). Conversely, all 9 LBD+ participants had low 18F-dopamine–derived radioactivity before or at the time of diagnosis of a central LBD, whereas among 25 participants without a central LBD only 1 (4%) had persistently low radioactivity (P < 0.0001 by Fisher’s exact test). CONCLUSION. Cardiac 18F-dopamine PET highly efficiently distinguishes at-risk individuals who are diagnosed subsequently with a central LBD from those who are not. TRIAL REGISTRATION. ClinicalTrials.gov NCT00775853. FUNDING. Division of Intramural Research, NIH, NINDS.
Authors
David S. Goldstein, Courtney Holmes, Patti Sullivan, Grisel Lopez, Janna Gelsomino, Sarah Moore, Risa Isonaka, Tianxia Wu, Yehonatan Sharabi
×Abstract
BACKGROUND Systemic administration of adeno-associated virus (AAV) can trigger life-threatening inflammatory responses, including thrombotic microangiopathy (TMA), acute kidney injury due to atypical hemolytic uremic syndrome–like complement activation, immune-mediated myocardial inflammation, and hepatic toxicity.METHODS We describe the kinetics of immune activation following systemic AAV serotype 9 (AAV9) administration in 38 individuals following 2 distinct prophylactic immunomodulation regimens. Group 1 received corticosteroids and Group 2 received rituximab plus sirolimus in addition to steroids to prevent anti-AAV antibody formation.RESULTS Group 1 participants had a rapid increase in immunoglobulin M (IgM) and IgG. Increase in D-dimer, decline in platelet count, and complement activation are indicative of TMA. All Group 1 participants demonstrated activation of both classical and alternative complement pathways, as indicated by depleted C4 and elevated soluble C5b-9, Ba, and Bb antigens. Group 2 patients did not have a significant change in IgM or IgG and had minimal complement activation.CONCLUSIONS This study demonstrates that TMA in the setting of AAV gene therapy is antibody dependent (classical pathway) and amplified by the alternative complement pathway. Critical time points and interventions are identified to allow for management of immune-mediated events that impact the safety and efficacy of systemic gene therapy.
Authors
Stephanie M. Salabarria, Manuela Corti, Kirsten E. Coleman, Megan B. Wichman, Julie A. Berthy, Precilla D’Souza, Cynthia J. Tifft, Roland W. Herzog, Melissa E. Elder, Lawrence R. Shoemaker, Carmen Leon-Astudillo, Fatemeh Tavakkoli, David H. Kirn, Jonathan D. Schwartz, Barry J. Byrne
×Abstract
The infertility of many couples rests on an enigmatic dysfunction of the man’s sperm. To gain insight into the underlying pathomechanisms, we assessed the function of the sperm-specific multisubunit CatSper-channel complex in the sperm of almost 2,300 men undergoing a fertility workup, using a simple motility-based test. We identified a group of men with normal semen parameters but defective CatSper function. These men or couples failed to conceive naturally and upon medically assisted reproduction via intrauterine insemination and in vitro fertilization. Intracytoplasmic sperm injection (ICSI) was, ultimately, required to conceive a child. We revealed that the defective CatSper function was caused by variations in CATSPER genes. Moreover, we unveiled that CatSper-deficient human sperm were unable to undergo hyperactive motility and, therefore, failed to penetrate the egg coat. Thus, our study provides the experimental evidence that sperm hyperactivation is required for human fertilization, explaining the infertility of CatSper-deficient men and the need of ICSI for medically assisted reproduction. Finally, our study also revealed that defective CatSper function and ensuing failure to hyperactivate represents the most common cause of unexplained male infertility known thus far and that this sperm channelopathy can readily be diagnosed, enabling future evidence-based treatment of affected couples.
Authors
Samuel Young, Christian Schiffer, Alice Wagner, Jannika Patz, Anton Potapenko, Leonie Herrmann, Verena Nordhoff, Tim Pock, Claudia Krallmann, Birgit Stallmeyer, Albrecht Röpke, Michelina Kierzek, Cristina Biagioni, Tao Wang, Lars Haalck, Dirk Deuster, Jan N. Hansen, Dagmar Wachten, Benjamin Risse, Hermann M. Behre, Stefan Schlatt, Sabine Kliesch, Frank Tüttelmann, Christoph Brenker, Timo Strünker
×Abstract
Myotonic dystrophy type 1 (DM1) involves misregulated alternative splicing for specific genes. We used exon or nucleotide deletion to mimic altered splicing of genes central to muscle excitation-contraction coupling in mice. Mice with forced skipping of exon 29 in the CaV1.1 calcium channel combined with loss of ClC-1 chloride channel function displayed markedly reduced lifespan, whereas other combinations of splicing mimics did not affect survival. The Ca2+/Cl– bi-channelopathy mice exhibited myotonia, weakness, and impairment of mobility and respiration. Chronic administration of the calcium channel blocker verapamil rescued survival and improved force generation, myotonia, and respiratory function. These results suggest that Ca2+/Cl– bi-channelopathy contributes to muscle impairment in DM1 and is potentially mitigated by common clinically available calcium channel blockers.
Authors
Lily A. Cisco, Matthew T. Sipple, Katherine M. Edwards, Charles A. Thornton, John D. Lueck
×Abstract
Cardiovascular diseases are the most common cause of worldwide morbidity and mortality, highlighting the necessity for advanced therapeutic strategies. Ca2+/calmodulin-dependent protein kinase IIδ (CaMKIIδ) is a prominent inducer of various cardiac disorders, which is mediated by 2 oxidation-sensitive methionine residues within the regulatory domain. We have previously shown that ablation of CaMKIIδ oxidation by CRISPR-Cas9 base editing enables the heart to recover function from otherwise severe damage following ischemia/reperfusion (IR) injury. Here, we extended this therapeutic concept toward potential clinical translation. We generated a humanized CAMK2D knockin mouse model in which the genomic sequence encoding the entire regulatory domain was replaced with the human sequence. This enabled comparison and optimization of two different editing strategies for the human genome in mice. To edit CAMK2D in vivo, we packaged the optimized editing components into an engineered myotropic adeno-associated virus (MyoAAV 2A), which enabled efficient delivery at a very low AAV dose into the humanized mice at the time of IR injury. CAMK2D-edited mice recovered cardiac function, showed improved exercise performance, and were protected from myocardial fibrosis, which was otherwise observed in injured control mice after IR. Our findings identify a potentially effective strategy for cardioprotection in response to oxidative damage.
Authors
Simon Lebek, Xurde M. Caravia, Leon G. Straub, Damir Alzhanov, Wei Tan, Hui Li, John R. McAnally, Kenian Chen, Lin Xu, Philipp E. Scherer, Ning Liu, Rhonda Bassel-Duby, Eric N. Olson
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ISSN: 0021-9738 (print), 1558-8238 (online)