Latest issue: February 27, 2020

In the issue

Abstract

Systemic lupus erythematosus (SLE) is a complex autoimmune disease that follows an unpredictable disease course and affects multiple organs and tissues. We performed an integrated, multicohort analysis of 7,471 transcriptomic profiles from 40 independent studies to identify robust gene expression changes associated with SLE. We identified a 93-gene signature (SLE MetaSignature) that is differentially expressed in the blood of patients with SLE compared with healthy volunteers; distinguishes SLE from other autoimmune, inflammatory, and infectious diseases; and persists across diverse tissues and cell types. The SLE MetaSignature correlated significantly with disease activity and other clinical measures of inflammation. We prospectively validated the SLE MetaSignature in an independent cohort of pediatric patients with SLE using a microfluidic quantitative PCR (qPCR) array. We found that 14 of the 93 genes in the SLE MetaSignature were independent of IFN-induced and neutrophil-related transcriptional profiles that have previously been associated with SLE. Pathway analysis revealed dysregulation associated with nucleic acid biosynthesis and immunometabolism in SLE. We further refined a neutropoiesis signature and identified underappreciated transcripts related to immune cells and oxidative stress. In our multicohort, transcriptomic analysis has uncovered underappreciated genes and pathways associated with SLE pathogenesis, with the potential to advance clinical diagnosis, biomarker development, and targeted therapeutics for SLE.

Authors

Winston A. Haynes, D. James Haddon, Vivian K. Diep, Avani Khatri, Erika Bongen, Gloria Yiu, Imelda Balboni, Christopher R. Bolen, Rong Mao, Paul J. Utz, Purvesh Khatri

×

Abstract

Group 2 innate lymphoid cells (ILC2s) are a critical innate source of type 2 cytokines in allergic inflammation. Although ILC2s are recognized as a critical cell population in the allergic inflammation, the regulatory mechanism(s) of ILC2s are less well understood. Here, we show that Regnase-1, an immune regulatory RNAse that degrades inflammatory mRNAs, negatively regulates ILC2 function and that IκB kinase (IKK) complex–mediated Regnase-1 degradation is essential for IL-33– and IL-25–induced ILC2 activation. ILC2s from Regnase-1AA/AA mice expressing a Regnase-1 S435A/S439A mutant resistant to IKK complex–mediated degradation accumulated Regnase-1 protein in response to IL-33 and IL-25. IL-33– and IL-25–stimulated Regnase-1AA/AA ILC2s showed reduced cell proliferation and type 2 cytokine (IL-5, IL-9, and IL-13) production and increased cell death. In addition, Il2ra and Il1rl1, but not Il5, Il9, or Il13, mRNAs were destabilized in IL-33–stimulated Regnase-1AA/AA ILC2s. In vivo, Regnase-1AA/AA mice showed attenuated acute type 2 pulmonary inflammation induced by the instillation of IL-33, IL-25, or papain. Furthermore, the expulsion of Nippostrongylus brasiliensis was significantly delayed in Regnase-1AA/AA mice. These results demonstrate that IKK complex–mediated Regnase-1 degradation is essential for ILC2-mediated type 2 responses both in vitro and in vivo. Therefore, controlling Regnase-1 degradation is a potential therapeutic target for ILC2-contributed allergic disorders.

Authors

Kazufumi Matsushita, Hiroki Tanaka, Koubun Yasuda, Takumi Adachi, Ayumi Fukuoka, Shoko Akasaki, Atsuhide Koida, Etsushi Kuroda, Shizuo Akira, Tomohiro Yoshimoto

×

Abstract

Cell therapy raises hopes high for better treatment of brain disorders. However, the majority of transplanted cells often die soon after transplantation, and those that survive initially continue to die in the subacute phase, diminishing the impact of transplantations. In this study, we genetically modified transplanted human neural stem cells (hNSCs), from 2 distant embryonic stem cell lines (H9 and RC17), to express 1 of 4 prosurvival factors — Hif1a, Akt1, Bcl-2, or Bcl-xl — and studied how these modifications improve short- and long-term survival of transplanted hNSCs. All genetic modifications dramatically increased survival of the transplanted hNSCs. Importantly, 3 out of 4 modifications also enhanced the exit of hNSCs from the cell cycle, thus avoiding aberrant growth of the transplants. Bcl-xl expression provided the strongest protection of transplanted cells, reducing both immediate and delayed cell death, and stimulated hNSC differentiation toward neuronal and oligodendroglial lineages. By designing hNSCs with drug-controlled expression of Bcl-xl, we demonstrated that short-term expression of a prosurvival factor can ensure the long-term survival of transplanted cells. Importantly, transplantation of Bcl-xl–expressing hNSCs into mice suffering from stroke improved behavioral outcome and recovery of motor activity in mice.

Authors

Irina Korshunova, Sina Rhein, Diego García-González, Ines Stölting, Ulrich Pfisterer, Anna Barta, Oksana Dmytriyeva, Agnete Kirkeby, Markus Schwaninger, Konstantin Khodosevich

×

Abstract

Inherited bone marrow failure syndromes, such as Fanconi anemia (FA) and Shwachman-Diamond syndrome (SDS), feature progressive cytopenia and a risk of acute myeloid leukemia (AML). Using deep phenotypic analysis of early progenitors in FA/SDS bone marrow samples, we revealed selective survival of progenitors that phenotypically resembled granulocyte-monocyte progenitors (GMP). Whole-exome and targeted sequencing of GMP-like cells in leukemia-free patients revealed a higher mutation load than in healthy controls and molecular changes that are characteristic of AML: increased G>A/C>T variants, decreased A>G/T>C variants, increased trinucleotide mutations at Xp(C>T)pT, and decreased mutation rates at Xp(C>T)pG sites compared with other Xp(C>T)pX sites and enrichment for Cancer Signature 1 (X indicates any nucleotide). Potential preleukemic targets in the GMP-like cells from patients with FA/SDS included SYNE1, DST, HUWE1, LRP2, NOTCH2, and TP53. Serial analysis of GMPs from an SDS patient who progressed to leukemia revealed a gradual increase in mutational burden, enrichment of G>A/C>T signature, and emergence of new clones. Interestingly, the molecular signature of marrow cells from 2 FA/SDS patients with leukemia was similar to that of FA/SDS patients without transformation. The predicted founding clones in SDS-derived AML harbored mutations in several genes, including TP53, while in FA-derived AML the mutated genes included ARID1B and SFPQ. We describe an architectural change in the hematopoietic hierarchy of FA/SDS with remarkable preservation of GMP-like populations harboring unique mutation signatures. GMP-like cells might represent a cellular reservoir for clonal evolution.

Authors

Stephanie Heidemann, Brian Bursic, Sasan Zandi, Hongbing Li, Sagi Abelson, Robert J. Klaassen, Sharon Abish, Meera Rayar, Vicky R. Breakey, Houtan Moshiri, Santhosh Dhanraj, Richard de Borja, Adam Shlien, John E. Dick, Yigal Dror

×

Abstract

Alcohol abuse is a major public health problem worldwide, causing a wide range of preventable morbidity and mortality. In this translational study, we show that heavy drinking (HD) (≥6 standard drinks/day) is independently associated with a worse outcome for ischemic stroke patients. To study the underlying mechanisms of this deleterious effect of HD, we performed an extensive analysis of the brain inflammatory responses of mice chronically exposed or not to 10% alcohol before and after ischemic stroke. Inflammatory responses were analyzed at the parenchymal, perivascular, and vascular levels by using transcriptomic, immunohistochemical, in vivo 2-photon microscopy and molecular MRI analyses. Alcohol-exposed mice show, in the absence of any other insult, a neurovascular inflammatory priming (i.e., an abnormal inflammatory status including an increase in brain perivascular macrophages [PVM]) associated with exacerbated inflammatory responses after a secondary insult (ischemic stroke or LPS challenge). Similar to our clinical data, alcohol-exposed mice showed larger ischemic lesions. We show here that PVM are key players on this aggravating effect of alcohol, since their specific depletion blocks the alcohol-induced aggravation of ischemic lesions. This study opens potentially new therapeutic avenues aiming at blocking alcohol-induced exacerbation of the neurovascular inflammatory responses triggered after ischemic stroke.

Authors

Antoine Drieu, Anastasia Lanquetin, Damien Levard, Martina Glavan, Francisco Campos, Aurélien Quenault, Eloïse Lemarchand, Mikaël Naveau, Anne Lise Pitel, José Castillo, Denis Vivien, Marina Rubio

×

Abstract

Small primary breast cancers can show surprisingly high potential for metastasis. Clinical decision-making for tumor aggressiveness, including molecular profiling, relies primarily on analysis of the cancer cells. Here we show that this analysis is insufficient — that the stromal microenvironment of the primary tumor plays a key role in tumor cell dissemination and implantation at distant sites. We previously described 2 cancer-associated fibroblasts (CAFs) that either express (CD146+) or lack (CD146–) CD146 (official symbol MCAM, alias MUC18). We now find that when mixed with human breast cancer cells, each fibroblast subtype determines the fate of cancer cells: CD146– fibroblasts promoted increased metastasis compared with CD146+ fibroblasts. Potentially novel quantitative and qualitative proteomic analyses showed that CD146+ CAFs produced an environment rich in basement membrane proteins, while CD146– CAFs exhibited increases in fibronectin 1, lysyl oxidase, and tenascin C, all overexpressed in aggressive disease. We also show clinically that CD146– CAFs predicted for likelihood of lymph node involvement even in small primary tumors (<5 cm). Clearly small tumors enriched for CD146– CAFs require aggressive treatments.

Authors

Heather M. Brechbuhl, Alexander S. Barrett, Etana Kopin, Jaime C. Hagen, Amy L. Han, Austin E. Gillen, Jessica Finlay-Schultz, Diana M. Cittelly, Philip Owens, Kathryn B. Horwitz, Carol A. Sartorius, Kirk Hansen, Peter Kabos

×

Abstract

The mitochondrial calcium uniporter is widely accepted as the primary route of rapid calcium entry into mitochondria, where increases in matrix calcium contribute to bioenergetics but also mitochondrial permeability and cell death. Hence, regulation of uniporter activity is critical to mitochondrial homeostasis. The uniporter subunit EMRE is known to be an essential regulator of the channel-forming protein MCU in cell culture, but EMRE’s impact on organismal physiology is less understood. Here we characterize a mouse model of EMRE deletion and show that EMRE is indeed required for mitochondrial calcium uniporter function in vivo. EMRE–/– mice are born less frequently; however, the mice that are born are viable, healthy, and do not manifest overt metabolic impairment, at rest or with exercise. Finally, to investigate the role of EMRE in disease processes, we examine the effects of EMRE deletion in a muscular dystrophy model associated with mitochondrial calcium overload.

Authors

Julia C. Liu, Nicole C. Syder, Nima S. Ghorashi, Thomas B. Willingham, Randi J. Parks, Junhui Sun, Maria M. Fergusson, Jie Liu, Kira M. Holmström, Sara Menazza, Danielle A. Springer, Chengyu Liu, Brian Glancy, Toren Finkel, Elizabeth Murphy

×

Abstract

Decades ago, investigators reported that mice lacking DLX1 and DLX2, transcription factors expressed in the enteric nervous system (ENS), die with possible bowel motility problems. These problems were never fully elucidated. We found that mice lacking DLX1 and DLX2 (Dlx1/2–/– mice) had slower small bowel transit and reduced or absent neurally mediated contraction complexes. In contrast, small bowel motility seemed normal in adult mice lacking DLX1 (Dlx1–/–). Even with detailed anatomic studies, we found no defects in ENS precursor migration, or neuronal and glial density in Dlx1/2–/– or Dlx1–/– mice. However, RNA sequencing of Dlx1/2–/– ENS revealed dysregulation of many genes, including vasoactive intestinal peptide (Vip). Using immunohistochemistry and reporter mice, we then found that Dlx1/2–/– mice have reduced VIP expression and fewer VIP-lineage neurons in their ENS. Our study reveals what we believe is a novel connection between Dlx genes and Vip and highlights the observation that dangerous bowel motility problems can occur in the absence of easily identifiable ENS structural defects. These findings may be relevant for disorders like chronic intestinal pseudo-obstruction (CIPO) syndrome.

Authors

Christina M. Wright, James P. Garifallou, Sabine Schneider, Heather L. Mentch, Deepika R. Kothakapa, Beth A. Maguire, Robert O. Heuckeroth

×

Abstract

Extracellular matrix and osmolarity influence the development and homeostasis of skeletal tissues through Rho GTPase–mediated alteration of the actin cytoskeleton. This study investigated whether the actin-branching Arp2/3 complex, a downstream effector of the Rho GTPases Cdc42 and Rac1, plays a critical role in maintaining the health of matrix-rich and osmotically loaded intervertebral discs and cartilage. Mice with constitutive intervertebral disc– and cartilage-specific deletion of the critical Arp2/3 subunit Arpc2 (Col2-Cre; Arpc2fl/fl) developed chondrodysplasia and spinal defects. Since these mice did not survive to adulthood, we generated mice with inducible Arpc2 deletion in disc and cartilage (Acan-CreERT2; Arpc2fl/fl). Inactivation of Arp2/3 at skeletal maturity resulted in growth plate closure, loss of proteoglycan content in articular cartilage, and degenerative changes in the intervertebral disc at 1 year of age. Chondrocytes with Arpc2 deletion showed compromised cell spreading on both collagen and fibronectin. Pharmacological inhibition of Cdc42 and Arp2/3 prevented the osmoadaptive transcription factor TonEBP/NFAT5 from recruiting cofactors in response to a hyperosmolarity challenge. Together, these findings suggest that Arp2/3 plays a critical role in cartilaginous tissues through the regulation of cell–extracellular matrix interactions and modulation of TonEBP-mediated osmoadaptation.

Authors

Steven Tessier, Alexandra C. Doolittle, Kimheak Sao, Jeremy D. Rotty, James E. Bear, Veronica Ulici, Richard F. Loeser, Irving M. Shapiro, Brian O. Diekman, Makarand V. Risbud

×

Abstract

Lesch-Nyhan disease (LND) is a rare monogenic disease caused by deficiency of the salvage pathway enzyme hypoxanthine-guanine phosphoribosyltransferase (HGPRT). LND is characterized by severe neuropsychiatric symptoms that currently cannot be treated. Predictive in vivo models are lacking for screening and evaluating candidate drugs because LND-associated neurological symptoms are not recapitulated in HGPRT-deficient animals. Here, we used human neural stem cells and neurons derived from induced pluripotent stem cells (iPSCs) of children affected with LND to identify neural phenotypes of interest associated with HGPRT deficiency to develop a target-agnostic–based drug screening system. We screened more than 3000 molecules and identified 6 pharmacological compounds, all possessing an adenosine moiety, that corrected HGPRT deficiency–associated neuronal phenotypes by promoting metabolism compensations in an HGPRT-independent manner. This included S-adenosylmethionine, a compound that had already been used as a compassionate approach to ease the neuropsychiatric symptoms in LND. Interestingly, these compounds compensate abnormal metabolism in a manner complementary to the gold standard allopurinol and can be provided to patients with LND via simple food supplementation. This experimental paradigm can be easily adapted to other metabolic disorders affecting normal brain development and functioning in the absence of a relevant animal model.

Authors

Valentin Ruillier, Johana Tournois, Claire Boissart, Marie Lasbareilles, Gurvan Mahé, Laure Chatrousse, Michel Cailleret, Marc Peschanski, Alexandra Benchoua

×

Abstract

BACKGROUND The relative stabilities of the intact and defective HIV genomes over time during effective antiretroviral therapy (ART) have not been fully characterized.METHODS We used the intact proviral DNA assay (IPDA) to estimate the rate of change of intact and defective proviruses in HIV-infected adults on ART. We used linear spline models with a knot at seven years and a random intercept and slope up to the knot. We estimated the influence of covariates on rates of change.RESULTS We studied 81 individuals for a median of 7.3 (IQR 5.9-9.6) years. Intact genomes declined more rapidly from initial suppression through seven years (15.7% per year decline; 95% CI -22.8%, -8.0%) and more slowly after seven years (3.6% per year; 95% CI -8.1%, +1.1%). The estimated half-life of the reservoir was 4.0 years (95% CI 2.7-8.3) until year seven and 18.7 years (95% CI 8.2-infinite) thereafter. There was substantial variability between individuals in the rate of decline until year seven. Intact provirus declined more rapidly than defective provirus (P < 0.001) and showed a faster decline in individuals with higher CD4+ T cell nadirs.CONCLUSION The biology of the replication-competent (intact) reservoir differs from that of the replication-incompetent (non-intact) pool of proviruses. The IPDA will likely be informative when investigating the impact of interventions targeting the reservoir.FUNDING Delaney AIDS Research Enterprise, UCSF/Gladstone Institute of Virology & Immunology CFAR, CFAR Network of Integrated Systems, amfAR Institute for HIV Cure Research, I4C and Beat-HIV Collaboratories, Howard Hughes Medical Institute, Gilead Sciences, Bill and Melinda Gates Foundation.

Authors

Michael J. Peluso, Peter Bacchetti, Kristen D. Ritter, Subul Beg, Jun Lai, Jeffrey N. Martin, Peter W. Hunt, Timothy J. Henrich, Janet D. Siliciano, Robert F. Siliciano, Gregory M. Laird, Steven G. Deeks

×

Abstract

Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic cause of end-stage renal disease (ESRD). The treatment options for ADPKD are limited. We observed an upregulation in several IGF-1 pathway genes in the kidney of Pkd1RC/RC mice, a model of ADPKD. Pregnancy-associated plasma protein A (PAPP-A), a metalloproteinase that cleaves inhibitory IGF binding proteins (IGFBPs), increasing the local bioactivity of IGF-1, was highly induced in the kidney of ADPKD mice. PAPP-A levels were high in cystic fluid and kidneys of humans with ADPKD. Our studies further showed that PAPP-A transcription in ADPKD was mainly regulated through the cAMP/CREB/CBP/p300 pathway. Pappa deficiency effectively inhibited the development of cysts in the Pkd1RC/RC mice. The role of PAPP-A in cystic disease appears to be regulation of the IGF-1 pathway and cellular proliferation in the kidney. Finally, preclinical studies demonstrated that treatment with a monoclonal antibody that blocks the proteolytic activity of PAPP-A against IGFBP4 ameliorated ADPKD cystic disease in vivo in Pkd1RC/RC mice and ex vivo in embryonic kidneys. These data indicated that the PAPP-A/IGF-1 pathway plays an important role in the growth and expansion of cysts in ADPKD. Our findings introduce a therapeutic strategy for ADPKD that involves the inhibition of PAPP-A.

Authors

Sonu Kashyap, Kyaw Zaw Hein, Claudia C.S. Chini, Jorgo Lika, Gina M. Warner, Laurie K. Bale, Vicente E. Torres, Peter C. Harris, Claus Oxvig, Cheryl A. Conover, Eduardo N. Chini

×

Abstract

Pulmonary Langerhans cell histiocytosis (PLCH) is a rare smoking-related lung disease characterized by dendritic cell (DC) accumulation, bronchiolocentric nodule formation, and cystic lung remodeling. Approximately 50% of patients with PLCH harbor somatic BRAF-V600E mutations in cells of the myeloid/monocyte lineage. However, the rarity of the disease and lack of animal models have impeded the study of PLCH pathogenesis. Here, we establish a cigarette smoke–exposed (CS-exposed) BRAF-V600E–mutant mouse model that recapitulates many hallmark characteristics of PLCH. We show that CD11c-targeted expression of BRAF-V600E increases DC responsiveness to stimuli, including the chemokine CCL20, and that mutant cell accumulation in the lungs of CS-exposed mice is due to both increased cellular viability and enhanced recruitment. Moreover, we report that the chemokine CCL7 is secreted from DCs and human peripheral blood monocytes in a BRAF-V600E–dependent manner, suggesting a possible mechanism for recruitment of cells known to dominate PLCH lesions. Inflammatory lesions and airspace dilation in BRAF-V600E mice in response to CS are attenuated by transitioning animals to filtered air and treatment with a BRAF-V600E inhibitor, PLX4720. Collectively, this model provides mechanistic insights into the role of myelomonocytic cells and the BRAF-V600E mutation and CS exposure in PLCH pathogenesis and provides a platform to develop biomarkers and therapeutic targets.

Authors

Huan Liu, Andrew R. Osterburg, Jennifer Flury, Zulma Swank, Dennis W. McGraw, Nishant Gupta, Kathryn A. Wikenheiser-Brokamp, Ashish Kumar, Abdellatif Tazi, Yoshikazu Inoue, Masaki Hirose, Francis X. McCormack, Michael T. Borchers

×

Abstract

Adequate iron supply during pregnancy is essential for fetal development. However, how fetal or amniotic fluid iron levels are regulated during healthy pregnancy, or pregnancies complicated by intraamniotic infection or inflammation (IAI), is unknown. We evaluated amniotic fluid and fetal iron homeostasis in normal and complicated murine, macaque, and human pregnancy. In mice, fetal iron endowment was affected by maternal iron status, but amniotic fluid iron concentrations changed little during maternal iron deficiency or excess. In murine and macaque models of inflamed pregnancy, the fetus responded to maternal systemic inflammation or IAI by rapidly upregulating hepcidin and lowering iron in fetal blood, without altering amniotic fluid iron. In humans, elevated cord blood hepcidin with accompanying hypoferremia was observed in pregnancies with antenatal exposure to IAI compared with those that were nonexposed. Hepcidin was also elevated in human amniotic fluid from pregnancies with IAI compared with those without IAI, but amniotic fluid iron levels did not differ between the groups. Our studies in mice, macaques, and humans demonstrate that amniotic fluid iron is largely unregulated but that the rapid induction of fetal hepcidin by inflammation and consequent fetal hypoferremia are conserved mechanisms that may be important in fetal host defense.

Authors

Allison L. Fisher, Veena Sangkhae, Pietro Presicce, Claire A. Chougnet, Alan H. Jobe, Suhas G. Kallapur, Sammy Tabbah, Catalin S. Buhimschi, Irina A. Buhimschi, Tomas Ganz, Elizabeta Nemeth

×

Abstract

The HIV latent reservoir in resting memory CD4+ T cells precludes cure. Therapeutics to reactivate and eliminate this reservoir are in clinical trials in adults, but not yet in pediatric populations. We determined, ex vivo, the inducibility of the latent reservoir in perinatal infection as compared with adult infections using the Tat/rev induced limiting dilution assay (TILDA), in which a single round (12 hours) of CD4+ T cell stimulation with PMA/ionomycin maximally activates T cells and leads to proviral expression with multiply spliced HIV RNA production. Markers of immune activation and exhaustion were measured to assess interactions with inducibility. Although rates of T cell activation with PMA/ionomycin were similar, the latent reservoir in perinatal infection was slower to reactivate and of lower magnitude compared with adult infection, independent of proviral load. An enhanced TILDA with the addition of phytohemagglutin and a duration of 18 hours augmented proviral expression in perinatal but not adult infection. The baseline HLA-DR+CD4+ T cell level was significantly lower in perinatal compared with adult infections, but not correlated with induced reservoir size. These data support the hypothesis that there are differences in kinetics of latency reversal and baseline immune activation in perinatal compared with adult infections, with implications for latency reversal strategies toward reservoir clearance and remission.

Authors

Adit Dhummakupt, Jessica H. Rubens, Thuy Anderson, Laura Powell, Bareng A.S. Nonyane, Lilly V. Siems, Aleisha Collinson-Streng, Tricia Nilles, R. Brad Jones, Vicki Tepper, Allison Agwu, Deborah Persaud

×

Abstract

Community-acquired pneumonia is a widespread disease with significant morbidity and mortality. Alveolar macrophages are tissue-resident lung cells that play a crucial role in innate immunity against bacteria that cause pneumonia. We hypothesized that alveolar macrophages display adaptive characteristics after resolution of bacterial pneumonia. We studied mice 1 to 6 months after self-limiting lung infections with Streptococcus pneumoniae, the most common cause of bacterial pneumonia. Alveolar macrophages, but not other myeloid cells, recovered from the lung showed long-term modifications of their surface marker phenotype. The remodeling of alveolar macrophages was (a) long-lasting (still observed 6 months after infection), (b) regionally localized (observed only in the affected lobe after lobar pneumonia), and (c) associated with macrophage-dependent enhanced protection against another pneumococcal serotype. Metabolomic and transcriptomic profiling revealed that alveolar macrophages of mice that recovered from pneumonia had new baseline activities and altered responses to infection that better resembled those of adult humans. The enhanced lung protection after mild and self-limiting bacterial respiratory infections includes a profound remodeling of the alveolar macrophage pool that is long-lasting; compartmentalized; and manifest across surface receptors, metabolites, and both resting and stimulated transcriptomes.

Authors

Antoine Guillon, Emad I. Arafa, Kimberly A. Barker, Anna C. Belkina, Ian Martin, Anukul T. Shenoy, Alicia K. Wooten, Carolina Lyon De Ana, Anqi Dai, Adam Labadorf, Jaileene Hernandez Escalante, Hans Dooms, Hélène Blasco, Katrina E. Traber, Matthew R. Jones, Lee J. Quinton, Joseph P. Mizgerd

×

Abstract

In recent years, chimeric antigen receptor–modified T cell (CAR T cell) therapy has proven to be a promising approach against cancer. Nonetheless, this approach still faces multiple challenges in eliminating solid tumors, one of which being the immunosuppressive tumor microenvironment (TME). Here, we demonstrated that knocking out the endogenous TGF-β receptor II (TGFBR2) in CAR T cells with CRISPR/Cas9 technology could reduce the induced Treg conversion and prevent the exhaustion of CAR T ce lls. Meanwhile, TGFBR2-edited CAR T cells had better in vivo tumor elimination efficacy, both in cell line–derived xenograft and patient-derived xenograft solid tumor models, whether administered locally or systemically. In addition, the TGFBR2-edited CAR T cells could eliminate contralaterally reinoculated xenografts in mice effectively, with an increased proportion of memory subsets within circulating CAR T cells of central memory and effector memory subsets. In conclusion, we greatly improved the in vitro and in vivo function of CAR T cells in TGF-β–rich tumor environments by knocking out endogenous TGFBR2 and propose a potentially new method to improve the efficacy of CAR T cell therapy for treating solid tumors.

Authors

Na Tang, Chen Cheng, Xingying Zhang, Miaomiao Qiao, Na Li, Wei Mu, Xiao-Fei Wei, Weidong Han, Haoyi Wang

×

Abstract

BACKGROUND Liver disease in urea cycle disorders (UCDs) ranges from hepatomegaly and chronic hepatocellular injury to cirrhosis and end-stage liver disease. However, the prevalence and underlying mechanisms are unclear.METHODS We estimated the prevalence of chronic hepatocellular injury in UCDs using data from a multicenter, longitudinal, natural history study. We also used ultrasound with shear wave elastography and FibroTest to evaluate liver stiffness and markers of fibrosis in individuals with argininosuccinate lyase deficiency (ASLD), a disorder with high prevalence of elevated serum alanine aminotransferase (ALT). To understand the human observations, we evaluated the hepatic phenotype of the AslNeo/Neo mouse model of ASLD.RESULTS We demonstrate a high prevalence of elevated ALT in ASLD (37%). Hyperammonemia and use of nitrogen-scavenging agents, 2 markers of disease severity, were significantly (P < 0.001 and P = 0.001, respectively) associated with elevated ALT in ASLD. In addition, ultrasound with shear wave elastography and FibroTest revealed increased echogenicity and liver stiffness, even in individuals with ASLD and normal aminotransferases. The AslNeo/Neo mice mimic the human disorder with hepatomegaly, elevated aminotransferases, and excessive hepatic glycogen noted before death (3–5 weeks of age). This excessive hepatic glycogen is associated with impaired hepatic glycogenolysis and decreased glycogen phosphorylase and is rescued with helper-dependent adenovirus expressing Asl using a liver-specific (ApoE) promoter.CONCLUSION Our results link urea cycle dysfunction and impaired hepatic glucose metabolism and identify a mouse model of liver disease in the setting of urea cycle dysfunction.TRIAL REGISTRATION This study has been registered at ClinicalTrials.gov (NCT03721367, NCT00237315).FUNDING Funding was provided by NIH, Burroughs Wellcome Fund, NUCDF, Genzyme/ACMG Foundation, and CPRIT.

Authors

Lindsay C. Burrage, Simran Madan, Xiaohui Li, Saima Ali, Mahmoud Mohammad, Bridget M. Stroup, Ming-Ming Jiang, Racel Cela, Terry Bertin, Zixue Jin, Jian Dai, Danielle Guffey, Milton Finegold, Members of the Urea Cycle Disorders Consortium (UCDC), Sandesh Nagamani, Charles G. Minard, Juan Marini, Prakash Masand, Deborah Schady, Benjamin L. Shneider, Daniel H. Leung, Deeksha Bali, Brendan Lee

×

Abstract

Some effector CD4+ T cell subsets display cytotoxic activity, thus breaking the functional dichotomy of CD4+ helper and CD8+ cytotoxic T lymphocytes. However, molecular mechanisms regulating CD4+ cytotoxic T lymphocyte (CD4+ CTL) differentiation are poorly understood. Here we show that levels of histone deacetylases 1 and 2 (HDAC1-HDAC2) are key determinants of CD4+ CTL differentiation. Deletions of both Hdac1 and 1 Hdac2 alleles (HDAC1cKO-HDAC2HET) in CD4+ T cells induced a T helper cytotoxic program that was controlled by IFN-γ–JAK1/2–STAT1 signaling. In vitro, activated HDAC1cKO-HDAC2HET CD4+ T cells acquired cytolytic activity and displayed enrichment of gene signatures characteristic of effector CD8+ T cells and human CD4+ CTLs. In vivo, murine cytomegalovirus–infected HDAC1cKO-HDAC2HET mice displayed a stronger induction of CD4+ CTL features compared with infected WT mice. Finally, murine and human CD4+ T cells treated with short-chain fatty acids, which are commensal-produced metabolites acting as HDAC inhibitors, upregulated CTL genes. Our data demonstrate that HDAC1-HDAC2 restrain CD4+ CTL differentiation. Thus, HDAC1-HDAC2 might be targets for the therapeutic induction of CD4+ CTLs.

Authors

Teresa Preglej, Patricia Hamminger, Maik Luu, Tanja Bulat, Liisa Andersen, Lisa Göschl, Valentina Stolz, Ramona Rica, Lisa Sandner, Darina Waltenberger, Roland Tschismarov, Thomas Faux, Thorina Boenke, Asta Laiho, Laura L. Elo, Shinya Sakaguchi, Günter Steiner, Thomas Decker, Barbara Bohle, Alexander Visekruna, Christoph Bock, Birgit Strobl, Christian Seiser, Nicole Boucheron, Wilfried Ellmeier

×

Abstract

The 2018 National MD-PhD Program Outcomes Study highlighted the critical need to increase MD-PhD trainee diversity and close the gender gap in MD-PhD enrollment. This Association of American Medical Colleges imperative prompted us to evaluate trends in female matriculation from our institutional MD-PhD program compared with national data. Based on a 10-year review of Harvard/MIT Medical Scientist Training Program admissions, we observed a sharp and sustained increase in female matriculants for the past 5 years that is well above the national average. We report our experience with achieving gender parity among matriculants of our MD-PhD program, identify the specific stage of the admissions process where the gender balance acutely shifted, and attribute the increase in female matriculation to concrete administrative changes that were put into place just prior to the observed gender balance shift. These changes included increasing the number of faculty participants in application screening and awardee selection and establishing gender balance among faculty decision makers. We believe that adopting basic administrative practices geared toward increasing the diversity of perspectives among admissions faculty has the potential to expedite gender parity of MD-PhD matriculants nationwide and could eventually help achieve gender balance in the national physician-scientist workforce.

Authors

Temperance R. Rowell, Robert A. Redd, Donna S. Neuberg, Loren D. Walensky

×

In-Press Preview - More

Abstract

We hypothesized that skeletal muscle contraction produces a cellular stress signal triggering adipose tissue lipolysis to sustain fuel availability during exercise. The present study aimed at identifying novel exercise-regulated myokines, also known as exerkines, able to promote lipolysis.Human primary myotubes from lean healthy volunteers were submitted to electrical pulse stimulation (EPS) to mimic either acute intense or chronic moderate exercise. Conditioned media (CM) experiments with human adipocytes were performed. Conditioned media and human plasma samples were analyzed using unbiased proteomic and/or ELISA. Real-time qPCR was performed in cultured myotubes and muscle biopsy samples.CM from both acute intense and chronic moderate exercise increased basal lipolysis in human adipocytes (1.3 to 8 fold, p<0.001). Growth and Differentiation Factor 15 (GDF15) gene expression and secretion increased rapidly upon skeletal muscle contraction. GDF15 protein was up-regulated in CM from both acute and chronic exercise-stimulated myotubes. We further show that physiological concentrations of recombinant GDF15 protein increase lipolysis in human adipose tissue, while blocking GDF15 with a neutralizing antibody abrogates EPS CM-mediated lipolysis.We herein provide the first evidence that GDF15 is a novel exerkine produced by skeletal muscle contraction and able to target human adipose tissue to promote lipolysis.

Authors

Claire Laurens, Anisha Parmar, Enda Murphy, Deborah Carper, Benjamin Lair, Pauline Maes, Julie Vion, Nathalie Boulet, Coralie Fontaine, Marie-Adeline Marqués, Dominique Larrouy, Isabelle Harant, Claire Thalamas, Emilie Montastier, Sylvie Caspar-Bauguil, Virginie Bourlier, Geneviève Tavernier, Jean-Louis Grolleau, Anne Bouloumié, Dominique Langin, Nathalie Viguerie, Fabrice Bertile, Stéphane Blanc, Isabelle de Glisezinski, Donal J. O'Gorman, Cedric Moro

×

Abstract

Patients with active acromegaly (ACRO) exhibit low hepatocellular lipids (HCL) despite pronounced insulin resistance (IR). This contrasts the strong association of IR with non-alcoholic fatty liver disease in the general population. Since low HCL in acromegaly might be caused by changes in oxidative substrate metabolism, we investigated mitochondrial activity and plasma metabolomics/lipidomics in active acromegaly. Fifteen ACRO and seventeen healthy controls (CON) matched for age, BMI, gender and body composition underwent 31P/1H-7T-MR-spectroscopy of the liver and skeletal muscle, as well as plasma metabolomic profiling and an oral glucose tolerance test. ACRO showed significant lower HCL but ATP-synthesis rate was significantly increased compared to CON. Furthermore, a decreased ratio of unsaturated to saturated intrahepatocellular fatty acids was found in ACRO. Within assessed plasma lipids, lipidomics, and metabolomics, decreased carnitine species also indicate increased mitochondrial activity. We therefore conclude that excess of growth hormone (GH) in humans counteracts hepatocellular lipid accumulation by increased hepatic ATP-synthesis. This is accompanied by a decreased ratio of unsaturated-to-saturated lipids in hepatocytes and by a metabolomic profile reflecting the increase in mitochondrial activity. Thus, these findings help to better understand GH-regulated antisteatotic pathways and provide a better insight into potential novel therapeutic targets for treating NAFLD.

Authors

Paul Fellinger, Peter Wolf, Lorenz Pfleger, Patrik Krumpolec, Martin Krssak, Kristaps Klavins, Stefan Wolfsberger, Alexander Micko, Patricia Carey, Bettina Gürtl, Greisa Vila, Wolfgang Raber, Clemens Fürnsinn, Thomas Scherer, Siegfried Trattnig, Alexandra Kautzky-Willer, Michael Krebs, Yvonne Winhofer

×

Abstract

Background Salt-sensitive hypertension is often accompanied by insulin resistance in obese individuals, but the underlying mechanisms are obscure. Microvascular function is known to affect both salt-sensitivity of blood pressure and metabolic insulin sensitivity. We hypothesized that excessive salt intake increases blood pressure and decreases insulin-mediated glucose disposal, at least in part by impairing insulin-mediated muscle microvascular recruitment (IMMR). Methods In 20 lean and 20 abdominally obese individuals, we assessed mean arterial pressure (MAP; 24h ABPM), insulin-mediated whole body glucose disposal (M/I-value; hyperinsulinemic, euglycemic clamp technique), IMMR (contrast enhanced ultrasound), osmolyte and water balance, and excretion of mineralocorticoids, glucocorticoids, and amino and organic acids after a low and high salt diet during seven days in a randomized double-blind cross-over design. Results On a low, as compared to a high salt intake, MAP was lower, M/I-value was lower and IMMR was greater in both lean and abdominally obese individuals. In addition, Ln IMMR was inversely associated with MAP in lean participants on a low salt diet only. On a high salt diet, free water clearance decreased, and excretion of glucocorticoids and of amino acids involved in the urea cycle increased. Conclusion Our findings imply that hemodynamic and metabolic changes resulting from alterations in salt intake are not necessarily associated. Moreover, they are consistent with the concept that a high salt intake increases muscle glucose uptake as a response to high-salt-induced, glucocorticoid-drive muscle catabolism to stimulate urea production and thereby renal water conservation. Clinical Trial Registration Number: NCT02068781

Authors

Monica T.J. Schütten, Yvo H.A.M. Kusters, Alfons J.H.M. Houben, Hanneke E. C. Niessen, Jos op 't Roodt, Jean L.J. M. Scheijen, Marjo P. van de Waarenburg, Casper G. Schalkwijk, Peter W. de Leeuw, Coen D.A. Stehouwer

×

Abstract

To define cellular mechanisms underlying kidney function and failure, the Kidney Precision Medicine Project (KPMP) analyzes biopsy tissue in a multi-center research network to build cell-level process maps of kidney. This study aimed to establish a single cell RNA sequencing strategy to use cell level transcriptional profiles from kidney biopsies in KPMP to define molecular subtypes in glomerular diseases.Using multiple sources of adult human kidney reference tissue samples, 22,268 single cell profiles passed KPMP quality control parameters. Unbiased clustering resulted in 31 distinct cell clusters that were linked to kidney and immune cell types using specific cell markers. Focusing on endothelial cell phenotypes, in silico and in situ hybridization methods assigned three discrete endothelial cell clusters to distinct renal vascular beds. Transcripts defining glomerular endothelial cell (GEC) were evaluated in biopsies from patients with ten different glomerular diseases in the NEPTUNE and ERCB cohort studies. Highest GEC scores were observed in patients with focal segmental glomerulosclerosis (FSGS). Molecular endothelial signatures suggested two distinct FSGS patient subgroups with alpha-2 macroglobulin (A2M) as a key downstream mediator of the endothelial cell phenotype. Finally, glomerular A2M transcript levels associated with lower proteinuria remission rates, linking endothelial function with long-term outcome in FSGS.

Authors

Rajasree Menon, Edgar A. Otto, Paul J. Hoover, Sean Eddy, Laura H. Mariani, Bradley Godfrey, Celine C. Berthier, Felix Eichinger, Lalita Subramanian, Jennifer L. Harder, Wenjun Ju, Viji Nair, Maria Larkina, Abhijit S. Naik, Jinghui Luo, sanjay jain, Rachel Sealfon, Olga G. Troyanskaya, Nir Hacohen, Jeffrey B. Hodgin, Matthias Kretzler

×

Abstract

Plasma viral load (VL) and CD4+ T-cell count are widely used as biomarkers of HIV-1 replication, pathogenesis, and response to antiretroviral therapy (ART). However, the clinical potential of cell-associated (CA) HIV-1 molecular markers is much less understood. Here, we measured CA HIV-1 RNA and DNA in HIV-infected individuals treated with temporary ART initiated during primary HIV-1 infection. We demonstrate significant predictive value of CA RNA for: (a) the virological and immunological response to early ART, (b) the magnitude and time to viral rebound after discontinuation of early ART, and (c) the disease progression in the absence of treatment. Remarkably, when adjusted for CA RNA, plasma VL no longer appeared as an independent predictor of any clinical endpoint in this cohort. The potential of CA RNA as an HIV-1 clinical marker, in particular as a predictive biomarker of virological control after stopping ART, should be explored in the context of HIV-1 curative interventions.

Authors

Alexander O. Pasternak, Marlous L. Grijsen, Ferdinand W. Wit, Margreet Bakker, Suzanne Jurriaans, Jan M. Prins, Ben Berkhout

×