The Toll-like receptor 8 (TLR8) has an important role in innate immune responses to RNA viral infections, including respiratory syncytial virus (RSV). We previously reported that TLR8 expression was increased directly by the tumor suppressor and transcription factor p53 via a single nucleotide polymorphism (SNP) (rs3761624) in the TLR8 promoter, thereby placing TLR8 in the p53/immune axis. Because this SNP is in linkage disequilibrium with other SNPs associated with several infectious diseases, we addressed the combined influence of p53 and the SNP on downstream inflammatory signaling in response to a TLR8 cognate ssRNA ligand. Using human primary lymphocytes, p53 induction by chemotherapeutic agents such as ionizing radiation caused SNP-dependent synergistic increases in IL-6 following incubation with an ssRNA ligand, as well as TLR8 RNA and protein expression along with p53 binding at the TLR-p53 SNP site. Because TLR8 is X-linked, the increases were generally reduced in heterozygous females. We found a corresponding association of the p53-responsive allele with RSV disease severity in infants hospitalized with RSV infection. We conclude that p53 can strongly influence TLR8-mediated immune responses and that knowledge of the p53-responsive SNP can inform diagnosis and prognosis of RSV disease and other diseases that might have a TLR8 component, including cancer.
Daniel Menendez, Joyce Snipe, Jacqui Marzec, Cynthia L. Innes, Fernando P. Polack, Mauricio T. Caballero, Shepherd H. Schurman, Steven R. Kleeberger, Michael A. Resnick
Fibronectin in the vascular wall promotes inflammatory activation of the endothelium during vascular remodeling and atherosclerosis. These effects are mediated in part by fibronectin binding to integrin α5, which recruits and activates phosphodiesterase 4D5 (PDE4D5) by inducing its dephosphorylation on an inhibitory site, S651. Active PDE then hydrolyzes antiinflammatory cAMP to facilitate inflammatory signaling. To test this model in vivo, we mutated the integrin binding site of PDE4D5 in mice. This mutation reduced endothelial inflammatory activation in atherosclerosis-prone regions of arteries and, in a hyperlipidemia model, reduced atherosclerotic plaque size while increasing markers of plaque stability. We then investigated the mechanism of PDE4D5 activation. Proteomics identified the PP2A regulatory subunit B55α as the factor recruiting PP2A to PDE4D5. The B55α-PP2A complex localized to adhesions and directly dephosphorylated PDE4D5. This interaction also, unexpectedly, stabilized the PP2A-B55α complex. The integrin-regulated, proatherosclerotic transcription factor Yap was also dephosphorylated and activated through this pathway. PDE4D5 therefore mediated matrix-specific regulation of endothelial cell phenotype via an unconventional adapter role, assembling and anchoring a multifunctional PP2A complex that has other targets. We believe these results may have widespread consequences for the control of cell function by integrins.
Sanguk Yun, Rui Hu, Melanie E. Schwaemmle, Alexander N. Scherer, Zhenwu Zhuang, Anthony J. Koleske, David C. Pallas, Martin A. Schwartz
Deciphering novel pathways that regulate liver lipid content has profound implications for understanding the pathophysiology of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Recent evidence suggests that the nuclear envelope is a site of regulation of lipid metabolism, but there is limited appreciation of the responsible mechanisms and molecular components within this organelle. We showed that conditional hepatocyte deletion of the inner nuclear membrane protein lamina-associated polypeptide 1 (LAP1) causes defective VLDL secretion and steatosis, including intranuclear lipid accumulation. LAP1 binds to and activates torsinA, an AAA+ ATPase that resides in the perinuclear space and continuous main ER. Deletion of torsinA from mouse hepatocytes caused even greater reductions in VLDL secretion and profound steatosis. Mice from both of the mutant lines studied developed hepatic steatosis and subsequent steatohepatitis on a regular chow diet in the absence of whole-body insulin resistance or obesity. Our results establish an essential role for the nuclear envelope–localized torsinA-LAP1 complex in hepatic VLDL secretion and suggest that the torsinA pathway participates in the pathophysiology of NAFLD.
Ji-Yeon Shin, Antonio Hernandez-Ono, Tatyana Fedotova, Cecilia Östlund, Michael J. Lee, Sarah B. Gibeley, Chun-Chi Liang, William T. Dauer, Henry N. Ginsberg, Howard J. Worman
There has been great progress in ocular gene therapy, but delivery of viral vectors to the retinal pigmented epithelium (RPE) and retina can be challenging. Subretinal injection, the preferred route of delivery for most applications, requires a surgical procedure that has risks. Herein we report a novel gene therapy delivery approach, suprachoroidal injection of AAV8 vectors, which is less invasive and could be done in an outpatient setting. Two weeks after suprachoroidal injection of AAV8.GFP in rats, GFP fluorescence covered 18.9% of RPE flat mounts and extended entirely around sagittal and transverse sections in RPE and photoreceptors. After 2 suprachoroidal injections of AAV8.GFP, GFP fluorescence covered 30.5% of RPE flat mounts. Similarly, widespread expression of GFP occurred in nonhuman primate and pig eyes after suprachoroidal injection of AAV8.GFP. Compared with subretinal injection in rats of RGX-314, an AAV8 vector expressing an anti-VEGF Fab, suprachoroidal injection of the same dose of RGX-314 resulted in similar expression of anti-VEGF Fab and similar suppression of VEGF-induced vascular leakage. Suprachoroidal AAV8 vector injection provides a noninvasive outpatient procedure to obtain widespread transgene expression in retina and RPE.
Kun Ding, Jikui Shen, Zibran Hafiz, Sean F. Hackett, Raquel Lima e Silva, Mahmood Khan, Valeria E. Lorenc, Daiqin Chen, Rishi Chadha, Minie Zhang, Sherri Van Everen, Nicholas Buss, Michele Fiscella, Olivier Danos, Peter A. Campochiaro
Checkpoint blockade antibodies have been approved as immunotherapy for multiple types of cancer, but the response rate and efficacy are still limited. There are few immunogenic cell death–inducing (ICD-inducing) drugs available that can kill cancer cells, enhance tumor immunogenicity, increase in vivo immune infiltration, and thereby boost a tumor response to immunotherapy. So far, the ICD markers have been identified as the few immunostimulating characteristics of dead cells, but whether the presence of such ICD markers on tumor cells translates into enhanced antitumor immunity in vivo is still being investigated. To identify anticancer drugs that could induce tumor cell death and boost T cell response, we performed drug screenings based on both an ICD reporter assay and a T cell activation assay. We showed that teniposide, a DNA topoisomerase II inhibitor, could induce high-mobility group box 1 (HMGB1) release and type I IFN signaling in tumor cells and that teniposide-treated tumor cells could activate antitumor T cell response both in vitro and in vivo. Mechanistically, teniposide induced tumor cell DNA damage and innate immune signaling, including NF-κB activation and stimulator of IFN genes–dependent (STING-dependent) type I IFN signaling, both of which contribute to the activation of dendritic cells and subsequent T cells. Furthermore, teniposide potentiated the antitumor efficacy of anti-PD1 in multiple types of mouse tumor models. Our findings showed that teniposide could trigger tumor immunogenicity and enabled a potential chemoimmunotherapeutic approach to potentiating the therapeutic efficacy of anti-PD1 immunotherapy.
Zining Wang, Jiemin Chen, Jie Hu, Hongxia Zhang, Feifei Xu, Wenzhuo He, Xiaojuan Wang, Mengyun Li, Wenhua Lu, Gucheng Zeng, Penghui Zhou, Peng Huang, Siyu Chen, Wende Li, Liang-ping Xia, Xiaojun Xia
BACKGROUND Spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein. New SMN-enhancing therapeutics are associated with variable clinical benefits. Limited knowledge of baseline and drug-induced SMN levels in disease-relevant tissues hinders efforts to optimize these treatments.METHODS SMN mRNA and protein levels were quantified in human tissues isolated during expedited autopsies.RESULTS SMN protein expression varied broadly among prenatal control spinal cord samples, but was restricted at relatively low levels in controls and SMA patients after 3 months of life. A 2.3-fold perinatal decrease in median SMN protein levels was not paralleled by comparable changes in SMN mRNA. In tissues isolated from nusinersen-treated SMA patients, antisense oligonucleotide (ASO) concentration and full-length (exon 7 including) SMN2 (SMN2-FL) mRNA level increases were highest in lumbar and thoracic spinal cord. An increased number of cells showed SMN immunolabeling in spinal cord of treated patients, but was not associated with an increase in whole-tissue SMN protein levels.CONCLUSIONS A normally occurring perinatal decrease in whole-tissue SMN protein levels supports efforts to initiate SMN-inducing therapies as soon after birth as possible. Limited ASO distribution to rostral spinal and brain regions in some patients likely limits clinical response of motor units in these regions for those patients. These results have important implications for optimizing treatment of SMA patients and warrant further investigations to enhance bioavailability of intrathecally administered ASOs.FUNDING SMA Foundation, SMART, NIH (R01-NS09677, R01-NS062269), Ionis Pharmaceuticals, and PTC Therapeutics. Biogen provided support for absolute real-time RT-PCR.
Daniel M. Ramos, Constantin d’Ydewalle, Vijayalakshmi Gabbeta, Amal Dakka, Stephanie K. Klein, Daniel A. Norris, John Matson, Shannon J. Taylor, Phillip G. Zaworski, Thomas W. Prior, Pamela J. Snyder, David Valdivia, Christine L. Hatem, Ian Waters, Nikhil Gupte, Kathryn J. Swoboda, Frank Rigo, C. Frank Bennett, Nikolai Naryshkin, Sergey Paushkin, Thomas O. Crawford, Charlotte J. Sumner
Steven B. Abramson, Paul J. Anderson, Jill P. Buyon, Bruce N. Cronstein, Thoru Pederson, Mark R. Philips, Charles N. Serhan
Mutations affecting the integrity of the essential torsin ATPase/cofactor system have been identified in a steadily increasing number of congenital disorders. Since most of these mutations affect brain function, much of the research has focused on deciphering disease etiology in the brain. However, torsin is expressed in a wide variety of nonneural tissues and is strictly conserved across species, including the lowest metazoans, suggesting that it plays roles extending beyond neurons. In this issue of the JCI, Shin et al. explored torsin function in the mammalian liver. The group reports major defects in hepatic lipid metabolism when the torsin system is compromised in mice. Remarkably, conditional deletion of either torsinA or its cofactor, lamina-associated polypeptide 1 (LAP1), resulted in fatty liver disease and steatohepatitis, likely from a secretion defect of VLDLs. This study considerably expands our understanding of torsin biology, while providing defined opportunities for future investigations of torsin function and dysfunction in human pathologies.
Sarah M. Prophet, Christian Schlieker
HVTN 505 is a preventative vaccine efficacy trial testing DNA followed by recombinant adenovirus serotype 5 (rAd5) in circumcised, Ad5-seronegative men and transgendered persons who have sex with men in the United States. Identified immune correlates of lower HIV-1 risk and a virus sieve analysis revealed that, despite lacking overall efficacy, vaccine-elicited responses exerted pressure on infecting HIV-1 viruses. To interrogate the mechanism of the antibody correlate of HIV-1 risk, we examined antigen-specific antibody recruitment of Fcγ receptors (FcγRs), antibody-dependent cellular phagocytosis (ADCP), and the role of anti-envelope (anti-Env) IgG3. In a prespecified immune correlates analysis, antibody-dependent monocyte phagocytosis and antibody binding to FcγRIIa correlated with decreased HIV-1 risk. Follow-up analyses revealed that anti-Env IgG3 breadth correlated with reduced HIV-1 risk, anti-Env IgA negatively modified infection risk by Fc effector functions, and that vaccine recipients with a specific FcγRIIa single-nucleotide polymorphism locus had a stronger correlation with decreased HIV-1 risk when ADCP, Env-FcγRIIa, and IgG3 binding were high. Additionally, FcγRIIa engagement correlated with decreased viral load setpoint in vaccine recipients who acquired HIV-1. These data support a role for vaccine-elicited anti–HIV-1 Env IgG3, antibody engagement of FcRs, and phagocytosis as potential mechanisms for HIV-1 prevention.
Scott D. Neidich, Youyi Fong, Shuying S. Li, Daniel E. Geraghty, Brian D. Williamson, William Chad Young, Derrick Goodman, Kelly E. Seaton, Xiaoying Shen, Sheetal Sawant, Lu Zhang, Allan C. deCamp, Bryan S. Blette, Mengshu Shao, Nicole L. Yates, Frederick Feely, Chul-Woo Pyo, Guido Ferrari, HVTN 505 Team, Ian Frank, Shelly T. Karuna, Edith M. Swann, John R. Mascola, Barney S. Graham, Scott M. Hammer, Magdalena E. Sobieszczyk, Lawrence Corey, Holly E. Janes, M. Juliana McElrath, Raphael Gottardo, Peter B. Gilbert, Georgia D. Tomaras
With almost 2 million new HIV-1 infections in 2018, a highly effective vaccine is imperative. Vaccine-elicited HIV-1 antibodies contribute to protection through multiple nonneutralizing activities, but the exact mechanisms remain unknown. In this issue of the JCI, Neidich and associates sought to determine how antibodies contributed to reducing the risk of HIV-1 acquisition in a phase IIb preventative vaccine efficacy trial, HVTN 505. Their studies revealed that antibody-dependent cellular phagocytosis (ADCP) and FcγRIIa binding were strongly associated with reduced HIV-1 risk; however, HIV-1 envelope–specific IgG3, IgA; and host FcγRIIa genotype also influenced risk. This study highlights the intricate interactions between antibodies and innate immune functions in humans.
Tysheena P. Charles, Cynthia A. Derdeyn
The pathophysiology of cellular injury and repair has been extensively studied in acute kidney injury (AKI) for more than 70 years. Although a great deal of knowledge has been generated, a debate over the importance of repairing damaged cells versus replacing them by proliferation remains. In this issue of the JCI, Kishi et al. demonstrate that following kidney epithelial cell injury, DNA repair, rather than cell proliferation, plays the central role in recovery and longevity by minimizing apoptosis, G2/M cell-cycle arrest, and subsequent fibrosis. This has important therapeutic implications and highlights the need for more sensitive techniques to evaluate functional, structural, and molecular recovery following injury.
Bruce A. Molitoris
A number of highly potent and broadly neutralizing antibodies (bNAbs) against the human immunodeficiency virus (HIV) have recently been shown to prevent transmission of the virus, suppress viral replication, and delay plasma viral rebound following discontinuation of antiretroviral therapy in animal models and infected humans. However, the degree and extent to which such bNAbs interact with primary lymphocytes have not been fully delineated. Here, we show that certain glycan-dependent bNAbs, such as PGT121 and PGT151, bind to B, activated T, and natural killer (NK) cells of HIV-infected and -uninfected individuals. Binding of these bNAbs, particularly PGT121 and PGT151, to activated CD4+ and CD8+ T cells was mediated by complex-type glycans and was abrogated by enzymatic inhibition of N-linked glycosylation. In addition, a short-term incubation of PGT151 and primary NK cells led to degranulation and cellular death. Our data suggest that the propensity of certain bNAbs to bind uninfected/bystander cells has the potential for unexpected outcomes in passive-transfer studies and underscore the importance of antibody screening against primary lymphocytes.
Jana Blazkova, Eric W. Refsland, Katherine E. Clarridge, Victoria Shi, J. Shawn Justement, Erin D. Huiting, Kathleen R. Gittens, Xuejun Chen, Stephen D. Schmidt, Cuiping Liu, Nicole Doria-Rose, John R. Mascola, Alonso Heredia, Susan Moir, Tae-Wook Chun
Maladaptive proximal tubule (PT) repair has been implicated in kidney fibrosis through induction of cell-cycle arrest at G2/M. We explored the relative importance of the PT DNA damage response (DDR) in kidney fibrosis by genetically inactivating ataxia telangiectasia and Rad3-related (ATR), which is a sensor and upstream initiator of the DDR. In human chronic kidney disease, ATR expression inversely correlates with DNA damage. ATR was upregulated in approximately 70% of Lotus tetragonolobus lectin–positive (LTL+) PT cells in cisplatin-exposed human kidney organoids. Inhibition of ATR resulted in greater PT cell injury in organoids and cultured PT cells. PT-specific Atr-knockout (ATRRPTC–/–) mice exhibited greater kidney function impairment, DNA damage, and fibrosis than did WT mice in response to kidney injury induced by either cisplatin, bilateral ischemia-reperfusion, or unilateral ureteral obstruction. ATRRPTC–/– mice had more cells in the G2/M phase after injury than did WT mice after similar treatments. In conclusion, PT ATR activation is a key component of the DDR, which confers a protective effect mitigating the maladaptive repair and consequent fibrosis that follow kidney injury.
Seiji Kishi, Craig R. Brooks, Kensei Taguchi, Takaharu Ichimura, Yutaro Mori, Akinwande Akinfolarin, Navin Gupta, Pierre Galichon, Bertha C. Elias, Tomohisa Suzuki, Qian Wang, Leslie Gewin, Ryuji Morizane, Joseph V. Bonventre
Antisense oligonucleotides (ASOs) targeting pathologic RNAs have shown promising therapeutic corrections for many genetic diseases including myotonic dystrophy (DM1). Thus, ASO strategies for DM1 can abolish the toxic RNA gain-of-function mechanism caused by nucleus-retained mutant DMPK (DM1 protein kinase) transcripts containing CUG expansions (CUGexps). However, systemic use of ASOs for this muscular disease remains challenging due to poor drug distribution to skeletal muscle. To overcome this limitation, we test an arginine-rich Pip6a cell-penetrating peptide and show that Pip6a-conjugated morpholino phosphorodiamidate oligomer (PMO) dramatically enhanced ASO delivery into striated muscles of DM1 mice following systemic administration in comparison with unconjugated PMO and other ASO strategies. Thus, low-dose treatment with Pip6a-PMO-CAG targeting pathologic expansions is sufficient to reverse both splicing defects and myotonia in DM1 mice and normalizes the overall disease transcriptome. Moreover, treated DM1 patient–derived muscle cells showed that Pip6a-PMO-CAG specifically targets mutant CUGexp-DMPK transcripts to abrogate the detrimental sequestration of MBNL1 splicing factor by nuclear RNA foci and consequently MBNL1 functional loss, responsible for splicing defects and muscle dysfunction. Our results demonstrate that Pip6a-PMO-CAG induces long-lasting correction with high efficacy of DM1-associated phenotypes at both molecular and functional levels, and strongly support the use of advanced peptide conjugates for systemic corrective therapy in DM1.
Arnaud F. Klein, Miguel A. Varela, Ludovic Arandel, Ashling Holland, Naira Naouar, Andrey Arzumanov, David Seoane, Lucile Revillod, Guillaume Bassez, Arnaud Ferry, Dominic Jauvin, Genevieve Gourdon, Jack Puymirat, Michael J. Gait, Denis Furling, Matthew J.A. Wood
A vaccine for hepatitis C virus (HCV) is urgently needed. Development of broadly neutralizing plasma antibodies during acute infection is associated with HCV clearance, but the viral epitopes of these plasma antibodies are unknown. Identifying these epitopes could define the specificity and function of neutralizing antibodies (NAbs) that should be induced by a vaccine. Here, we present the development and application of a high-throughput method that deconvolutes polyclonal anti-HCV NAbs in plasma, delineating the epitope specificities of anti-HCV NAbs in acute-infection plasma of 44 humans with subsequent clearance or persistence of HCV. Remarkably, we identified multiple broadly neutralizing antibody combinations that were associated with greater plasma neutralizing breadth and with HCV clearance. These studies have the potential to inform new strategies for vaccine development by identifying broadly neutralizing antibody combinations in plasma associated with the natural clearance of HCV, while also providing a high-throughput assay that could identify these responses after vaccination trials.
Valerie J. Kinchen, Guido Massaccesi, Andrew I. Flyak, Madeleine C. Mankowski, Michelle D. Colbert, William O. Osburn, Stuart C. Ray, Andrea L. Cox, James E. Crowe Jr, Justin R. Bailey
Cancer-associated mutations in the spliceosome gene SF3B1 create a neomorphic protein that produces aberrant mRNA splicing in hundreds of genes, but the ensuing biologic and therapeutic consequences of this missplicing are not well understood. Here we have provided evidence that aberrant splicing by mutant SF3B1 altered the transcriptome, proteome, and metabolome of human cells, leading to missplicing-associated downregulation of metabolic genes, decreased mitochondrial respiration, and suppression of the serine synthesis pathway. We also found that mutant SF3B1 induces vulnerability to deprivation of the nonessential amino acid serine, which was mediated by missplicing-associated downregulation of the serine synthesis pathway enzyme PHGDH. This vulnerability was manifest both in vitro and in vivo, as dietary restriction of serine and glycine in mice was able to inhibit the growth of SF3B1MUT xenografts. These findings describe a role for SF3B1 mutations in altered energy metabolism, and they offer a new therapeutic strategy against SF3B1MUT cancers.
W. Brian Dalton, Eric Helmenstine, Noel Walsh, Lukasz P. Gondek, Dhanashree S. Kelkar, Abigail Read, Rachael Natrajan, Eric S. Christenson, Barbara Roman, Samarjit Das, Liang Zhao, Robert D. Leone, Daniel Shinn, Taylor Groginski, Anil K. Madugundu, Arun Patil, Daniel J. Zabransky, Arielle Medford, Justin Lee, Alex J. Cole, Marc Rosen, Maya Thakar, Alexander Ambinder, Joshua Donaldson, Amy E. DeZern, Karen Cravero, David Chu, Rafael Madero-Marroquin, Akhilesh Pandey, Paula J. Hurley, Josh Lauring, Ben Ho Park
Histone H3K27 demethylase JMJD3 plays a critical role in gene expression and T cell differentiation. However, the role and mechanisms of JMJD3 in T cell trafficking remain poorly understood. Here, we show that JMJD3 deficiency in CD4+ T cells resulted in an accumulation of T cells in the thymus and reduction of T cell number in the secondary lymphoid organs. We identified PDLIM4 as a significantly downregulated target gene in JMJD3-deficient CD4+ T cells by gene profiling and ChIP-Seq analyses. We further showed that PDLIM4 functioned as an adaptor protein to interact with sphingosine-1 phosphate receptor 1 (S1P1) and filamentous actin (F-actin), thus serving as a key regulator of T cell trafficking. Mechanistically, JMJD3 bound to the promoter and gene-body regions of the Pdlim4 gene and regulated its expression by interacting with zinc finger transcription factor KLF2. Our findings have identified Pdlim4 as a JMJD3 target gene that affects T cell trafficking by cooperating with S1P1 and have provided insights into the molecular mechanisms by which JMJD3 regulates genes involved in T cell trafficking.
Chuntang Fu, Qingtian Li, Jia Zou, Changsheng Xing, Mei Luo, Bingnan Yin, Junjun Chu, Jiaming Yu, Xin Liu, Helen Y. Wang, Rong-Fu Wang
BACKGROUND RV144 is the only preventive HIV vaccine regimen demonstrating efficacy in humans. Attempting to build upon RV144 immune responses, we conducted a phase 1, multicenter, randomized, double-blind trial to assess the safety and immunogenicity of regimens substituting the DNA-HIV-PT123 (DNA) vaccine for ALVAC-HIV in different sequences or combinations with AIDSVAX B/E (protein).METHODS One hundred and four HIV-uninfected participants were randomized to 4 treatment groups (T1, T2, T3, and T4) and received intramuscular injections at 0, 1, 3, and 6 months (M): T1 received protein at M0 and M1 and DNA at M3 and M6; T2 received DNA at M0 and M1 and protein at M3 and M6; T3 received DNA at M0, M1, M3, and M6 with protein coadministered at M3 and M6; and T4 received protein and DNA coadministered at each vaccination visit.RESULTS All regimens were well tolerated. Antibodies binding to gp120 and V1V2 scaffold were observed in 95%–100% of participants in T3 and T4, two weeks after final vaccination at high magnitude. While IgG3 responses were highest in T3, a lower IgA/IgG ratio was observed in T4. Binding antibodies persisted at 12 months in 35%–100% of participants. Antibody-dependent cell-mediated cytotoxicity and tier 1 neutralizing-antibody responses had higher response rates for T3 and T4, respectively. CD4+ T cell responses were detectable in all treatment groups (32%–64%) without appreciable CD8+ T cell responses.CONCLUSION The DNA/protein combination regimens induced high-magnitude and long-lasting HIV V1V2–binding antibody responses, and early coadministration of the 2 vaccines led to a more rapid induction of these potentially protective responses.TRIAL REGISTRATION ClinicalTrials.gov NCT02207920.FUNDING National Institute of Allergy and Infectious Diseases (NIAID) grants UM1 AI068614, UM1 AI068635, UM1 AI068618, UM1 AI069511, UM1 AI069470, UM1 AI069534, P30 AI450008, UM1 AI069439, UM1 AI069481, and UM1 AI069496; the National Center for Advancing Translational Sciences, NIH (grant UL1TR001873); and the Bill & Melinda Gates Foundation (grant OPP52845).
Nadine G. Rouphael, Cecilia Morgan, Shuying S. Li, Ryan Jensen, Brittany Sanchez, Shelly Karuna, Edith Swann, Magdalena E. Sobieszczyk, Ian Frank, Gregory J. Wilson, Hong-Van Tieu, Janine Maenza, Aliza Norwood, James Kobie, Faruk Sinangil, Giuseppe Pantaleo, Song Ding, M. Juliana McElrath, Stephen C. De Rosa, David C. Montefiori, Guido Ferrari, Georgia D. Tomaras, Michael C. Keefer, the HVTN 105 Protocol Team and the NIAID HIV Vaccine Trials Network
Inflammatory bowel disease (IBD) is a chronic inflammatory disorder with rising incidence. Diseased tissues are heavily vascularized. Surprisingly, the pathogenic impact of the vasculature in IBD and the underlying regulatory mechanisms remain largely unknown. IFN-γ is a major cytokine in IBD pathogenesis, but in the context of the disease, it is almost exclusively its immune-modulatory and epithelial cell–directed functions that have been considered. Recent studies by our group demonstrated that IFN-γ also exerts potent effects on blood vessels. Based on these considerations, we analyzed the vessel-directed pathogenic functions of IFN-γ and found that it drives IBD pathogenesis through vascular barrier disruption. Specifically, we show that inhibition of the IFN-γ response in vessels by endothelial-specific knockout of IFN-γ receptor 2 ameliorates experimentally induced colitis in mice. IFN-γ acts pathogenic by causing a breakdown of the vascular barrier through disruption of the adherens junction protein VE-cadherin. Notably, intestinal vascular barrier dysfunction was also confirmed in human IBD patients, supporting the clinical relevance of our findings. Treatment with imatinib restored VE-cadherin/adherens junctions, inhibited vascular permeability, and significantly reduced colonic inflammation in experimental colitis. Our findings inaugurate the pathogenic impact of IFN-γ–mediated intestinal vessel activation in IBD and open new avenues for vascular-directed treatment of this disease.
Victoria Langer, Eugenia Vivi, Daniela Regensburger, Thomas H. Winkler, Maximilian J. Waldner, Timo Rath, Benjamin Schmid, Lisa Skottke, Somin Lee, Noo Li Jeon, Thomas Wohlfahrt, Viktoria Kramer, Philipp Tripal, Michael Schumann, Stephan Kersting, Claudia Handtrack, Carol I. Geppert, Karina Suchowski, Ralf H. Adams, Christoph Becker, Andreas Ramming, Elisabeth Naschberger, Nathalie Britzen-Laurent, Michael Stürzl
Two different antisense oligonucleotide–based (ASO-based) therapies are currently in clinical use to treat neuromuscular diseases. This success, for Duchenne muscular dystrophy and spinal muscular atrophy, offers hope not only for additional neuromuscular diseases, but also for other disorders that could benefit from RNA-targeted therapies. A major limitation for more widespread application of ASOs relates to relatively poor tissue penetration. In this issue of the JCI, Klein et al. showed that conjugating an ASO with an arginine-rich cell-penetrating peptide, Pip6a, enhanced delivery, resulting in corrective outcome for a mouse model of myotonic dystrophy. Linking ASOs to cell-penetrating peptides, or even other moieties, is an approach currently under development with treatment potential to expand to other disorders.
Elizabeth M. McNally, Brian D. Leverson
Novel approaches for adjunctive therapy are urgently needed for infections complicated by antibiotic-resistant pathogens and for patients with compromised immunity. Necrotizing fasciitis (NF) is a destructive skin and soft tissue infection. Despite treatment with systemic antibiotics and radical debridement of necrotic tissue, lethality remains high. The key iron regulatory hormone hepcidin was originally identified as a cationic antimicrobial peptide (AMP), but its putative expression and role in the skin, a major site of AMP production, has never been investigated. We report here that hepcidin production is induced in the skin of patients with Group A Streptococcal (GAS) NF. In a GAS-induced NF model, mice lacking hepcidin in keratinocytes failed to restrict systemic spread of infection from an initial tissue focus. Unexpectedly, this effect was due its ability to promote production of the CXCL1 chemokine by keratinocytes resulting in neutrophil recruitment. Unlike CXCL1, hepcidin is resistant to degradation by major GAS proteases and could therefore serve as a reservoir to maintain steady state levels of CXCL1 in infected tissue. Finally, injection of synthetic hepcidin at the site of infection can limit or completely prevent systemic spread of GAS infection suggesting that hepcidin agonists could have a therapeutic role in NF.
Mariangela Malerba, Sabine Louis, Sylvain Cuvellier, Srikanth Mairpady Shambat, Camille Hua, Camille Gomart, Agnès Fouet, Nicolas Ortonne, Jean-Winoc Decousser, Annelies S. Zinkernagel, Jacques R.R. Mathieu, Carole Peyssonnaux
Polymorphonuclear neutrophils (PMNs) are increasingly recognized to influence solid tumor development, but why their effects are so context-dependent and even frequently divergent remains poorly understood. Using an autochthonous mouse model of uterine cancer and the administration of respiratory hyperoxia as a means to improve tumor oxygenation, we provide in vivo evidence that hypoxia is a potent determinant of tumor-associated PMN phenotypes and direct PMN-tumor cell interactions. Upon relief of tumor hypoxia, PMNs were recruited less intensely to the tumor-bearing uterus but the recruited cells much more effectively killed tumor cells, an activity our data moreover suggested was mediated via their production of NADPH oxidase-derived reactive oxygen species and MMP-9. Simultaneously, their ability to promote tumor cell proliferation, which appeared mediated via their production of neutrophil elastase, was rendered less effective. Relieving tumor hypoxia thus greatly improved net PMN-dependent tumor control, leading to a massive reduction in tumor burden. Remarkably, this outcome was T cell-independent. Together, these findings identify key hypoxia-regulated molecular mechanisms through which PMNs directly induce tumor cell death and proliferation in vivo and suggest that the contrasting properties of PMNs in different tumor settings may in part reflect the effects of hypoxia on direct PMN-tumor cell interactions.
Karim Mahiddine, Adam Blaisdell, Stephany Ma, Amandine Créquer-Grandhomme, Clifford A. Lowell, Adrian Erlebacher
Patients with bladder cancer (BCa) with clinical lymph node (LN) metastasis have extremely poor prognosis. VEGF-C has been demonstrated to play vital roles in LN metastasis in BCa. However, approximately 20% of BCa with LN metastasis exhibits low VEGF-C expression, suggesting a VEGF-C-independent mechanism for LN metastasis of BCa. Herein, we demonstrated that BCa cell-secreted exosomes-mediated lymphangiogenesis promoted LN metastasis in BCa, which was in a VEGF-C-independent manner. We identified an exosomal long noncoding RNA (lncRNA), termed lymph node metastasis-associated transcript 2 (LNMAT2), stimulated HLEC tube formation and migration in vitro and enhanced tumor lymphangiogenesis and LN metastasis in vivo. Mechanistically, LNMAT2 was loaded to BCa cell-secreted exosomes by directly interacting with heterogeneous nuclear ribonucleoprotein A2B1 (hnRNPA2B1). Subsequently, exosomal LNMAT2 was internalized by HLECs and epigenetically upregulated prospero homeobox 1 (PROX1) expression by recruitment of hnRNPA2B1 and increasing the H3K4 trimethylation level in the PROX1 promoter, ultimately resulting in lymphangiogenesis and lymphatic metastasis. Therefore, our findings highlight a VEGF-C-independent mechanism of exosomal lncRNA-mediated LN metastasis and identify LNMAT2 as a therapeutic target for LN metastasis in BCa.
Changhao Chen, Yuming Luo, Wang He, Yue Zhao, Yao Kong, Hongwei Liu, Guangzheng Zhong, Yuting Li, Jun Li, Jian Huang, Rufu Chen, Tianxin Lin
Potentiating radiotherapy and chemotherapy by inhibiting DNA damage repair is proposed as a therapeutic strategy to improve outcomes for patients with solid tumors. However, this approach risks enhancing normal tissue toxicity as much as tumor toxicity, thereby limiting its translational impact. Using NU5455, a newly-identified highly-selective oral inhibitor of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) activity, we found that it was indeed possible to preferentially augment the effect of targeted-radiotherapy on human orthotopic lung tumors without influencing acute DNA-damage or a late radiation-induced toxicity (fibrosis) to normal mouse lung. Furthermore, while NU5455 administration increased both the efficacy and toxicity of a parenterally-administered topoisomerase inhibitor, it enhanced the activity of doxorubicin released locally in liver tumor xenografts without inducing any adverse effect. This strategy is particularly relevant to hepatocellular cancer which is treated clinically with localized drug-eluting beads and for which DNA-PKcs activity is reported to confer resistance to treatment. We conclude that transient pharmacological inhibition of DNA-PKcs activity is effective and tolerable when combined with localized DNA-damaging therapies and thus has promising clinical potential.
Catherine E. Willoughby, Yanyan Jiang, Huw D. Thomas, Elaine Willmore, Suzanne Kyle, Anita Wittner, Nicole Phillips, Yan Zhao, Susan J. Tudhope, Lisa Prendergast, Gesa Junge, Luiza Madia Lourenco, M. Raymond V. Finlay, Paul Turner, Joanne M. Munck, Roger J. Griffin, Tommy Rennison, James Pickles, Celine Cano, David R. Newell, Helen L. Reeves, Anderson J. Ryan, Stephen R. Wedge
Diabetes is a common complication of cystic fibrosis (CF) that affects approximately 20% of adolescents and 40% to 50% of adults with CF. The age-at-onset of CF-related diabetes (marked by clinical diagnosis and treatment initiation) is an important measure of the disease process. DNA variants associated with age-at-onset of CFRD reside in and near SLC26A9. Deep sequencing of the SLC26A9 gene in 762 individuals with CF revealed that two common DNA haplotypes formed by the risk variants account for the association with diabetes (high risk, P-value: 4.34E-3; low risk, P-value: 1.14E-3). Single-cell RNA (scRNA) sequencing indicated that SLC26A9 is predominantly expressed in pancreatic ductal cells, and frequently co-expressed with CFTR along with transcription factors that have binding sites 5′ of SLC26A9. These findings replicated upon re-analysis of scRNA data from 4 independent studies. DNA fragments derived from the 5′ region of SLC26A9 bearing variants from the low risk haplotype generated 12% to 20% higher levels of expression in PANC-1 and CFPAC-1 cells compared to the high risk haplotype (P-values: 2.00E-3 to 5.15E-9). Taken together, our findings indicate that an increase in SLC26A9 expression in ductal cells of the pancreas delays the age-at-onset of diabetes, thereby suggesting a CFTR-agnostic treatment for a major complication of CF.
Anh-Thu N. Lam, Melis A. Aksit, Briana Vecchio-Pagan, Celeste A. Shelton, Derek L. Osorio, Arianna F. Anzmann, Loyal A. Goff, David C. Whitcomb, Scott M. Blackman, Garry R. Cutting
The risk of developing atherosclerosis and cardiovascular disease is greater in patients with type 1 diabetes mellitus (T1DM), and the roles of lipoprotein-regulating proteins like APOC3 are relatively unexplored. In this issue, Kanter et al. observed that elevated serum APOC3 levels are a strong predictor of coronary artery disease incidents in T1DM patients. An APOC3-targeting antisense oligonucleotide (ASO) mitigated APOC3 elevations in diabetic mouse models as well as prevented accelerated atherogenesis, supporting APOC3-targeting strategies as potential interventions for T1DM-associated cardiovascular disease. On the cover, a mouse atherosclerotic lesion (Movat’s pentachrome stain), an ECG trace, and a heart-shaped lipoprotein particle highlight APOC3’s role in T1DM-linked cardiovascular disease. Image credit: Jenny Kanter and Karin Bornfeldt.
JCI This Month is a digest of the research, reviews, and other features published each month.
Obesity often occurs with a quintessential array of metabolic abnormalities: elevations in blood pressure, visceral fat, and circulating blood lipids, and, importantly, insulin resistance. Together, this constellation of conditions constitutes the metabolic syndrome and forecasts an individual’s increased risk of developing cardiovascular diseases and type 2 diabetes. Although metabolic syndrome presents as dysfunction across multiple tissues, its onset stems from pathological increases in adipose tissue. The 9 review in this series, conceptualized by series editor Philipp Scherer, delve into the complex biology underlying the metabolic syndrome. These reviews address adipocyte and beta cell dysfunction in the metabolic syndrome; the functions of adipose tissue fibrosis, the microbiome, and exosomal communication in obesity; and the concepts we use to define metabolic health.