Spinal muscular atrophy (SMA) is an inherited neuromuscular disorder caused by reduced expression of the survival motor neuron (SMN) protein. SMN has key functions in multiple RNA pathways, including the biogenesis of small nuclear ribonucleoproteins (snRNPs) that are essential components of both major (U2-dependent) and minor (U12-dependent) spliceosomes. Here we investigated the specific contribution of U12 splicing dysfunction to SMA pathology through selective restoration of this RNA pathway in mouse models of varying phenotypic severity. We show that viral-mediated delivery of minor snRNA genes specifically improves select U12 splicing defects induced by SMN deficiency in cultured mammalian cells as well as in the spinal cord and dorsal root ganglia of SMA mice without increasing SMN expression. This approach resulted in a moderate amelioration of several parameters of the disease phenotype in SMA mice including survival, weight gain and motor function. Importantly, minor snRNA gene delivery improved aberrant splicing of the U12 intron-containing gene Stasimon and rescued the severe loss of proprioceptive sensory synapses on SMA motor neurons, which are early signatures of motor circuit dysfunction in mouse models. Taken together, these findings establish the direct contribution of U12 splicing dysfunction to synaptic deafferentation and motor circuit pathology in SMA.
Erkan Y. Osman, Meaghan Van Alstyne, Pei-Fen Yen, Francesco Lotti, Zhihua Feng, Karen K.Y. Ling, Chien-Ping Ko, Livio Pellizzoni, Christian L. Lorson
Increased microvascular leakage is a cardinal feature of many critical diseases. Regular exercise is associated with improved endothelial function and reduced risk of cardiovascular disease. Irisin, secreted during exercise, contributes to many health benefits of exercise. However, the effects of irisin on endothelial function and microvascular leakage remain unknown. In this study, we found that irisin remarkably strengthened endothelial junctions and barrier function via binding to integrin αVβ5 receptor in LPS-treated endothelial cells. The beneficial effect of irisin was associated with suppression of the Src-MLCK-β-catenin pathway, activation of the AMPK-Cdc42/Rac1 pathway and improvement of mitochondrial function. In preclinical models of microvascular leakage, exogenous irisin improved pulmonary function, decreased lung edema and injury, suppressed inflammation, and increased survival. In ARDS patients, serum irisin levels were decreased and inversely correlated with disease severity and mortality. In conclusion, irisin enhances endothelial barrier function and mitigates microvascular leakage related diseases.
Jianbin Bi, Jia Zhang, Yifan Ren, Zhaoqing Du, Yuanyuan Zhang, Chang Liu, Yawen Wang, Lin Zhang, Zhihong Shi, Zheng Wu, Yi Lv, Rongqian Wu
Apelin is a well-established mediator of survival and mitogenic signalling through apelin receptor (Aplnr) and have been implicated in various cancers, however little is known regarding Elabela (ELA/APELA) signalling, also mediated by Aplnr, and its role and the role of the conversion of its precursor proELA into mature ELA in cancer are unknown. Here we identify a function of mTORC1 signalling as an essential mediator of ELA that represses kidney tumour cells growth, migration and survival. Moreover, sunitinib and ELA show synergistic effect in repressing tumour growth and angiogenesis in mice. The use of site directed mutagenesis and pharmacologic experiments provide evidence that the alteration of the cleavage site of proELA by Furin induced improved ELA anti-tumorigenic activity. Finally, cohort of tumours and public data sets revealed that ELA is only repressed in the main human kidney cancer subtypes namely clear cell, papillary, and chromophobe renal cell carcinoma. While Aplnr is expressed by various kidney cells, ELA is generally expressed by epithelial cells. Collectively, these results show the tumour-suppressive role of mTORC1 signalling mediated by ELA and establish the potential use of ELA or derivatives in kidney cancers treatment.
Fabienne Soulet, Clement Bodineau, Katarzyna B. Hooks, Jean Descarpentrie, Isabel D. Alves, Marielle Dubreuil, Amandine Mouchard, Malaurie Eugenie, Jean-Luc Hoepffner, José Javier Lopez, Juan A. Rosado, Isabelle Soubeyran, Mercedes Tomé, Raúl V. Durán, Macha Nikolski, Bruno O. Villoutreix, Serge Evrard, Geraldine Siegfried, Abdel-Majid Khatib
Background Identifying immune correlates of COVID-19 disease severity is an urgent need for clinical management, vaccine evaluation and drug development. Here we present a temporal analysis of key immune mediators, cytokine and chemokines in blood of hospitalised COVID-19 patients from serial sampling and follow up over four weeks. Methods A total of 71 patients with laboratory-confirmed COVID-19 admitted to Beijing You’an hospital in China with either mild (53 patients) or severe disease (18 patients) were enrolled with 18 healthy volunteers. We measured 34 immune mediators, cytokines and chemokines in peripheral blood every 4-7 days over one month per patient using a bio-plex multiplex immunoassay. Results We found that the chemokine RANTES(CCL5) was significantly elevated, from an early stage of the infection, in patients with mild but not severe disease. We also found that early production of inhibitory mediators including IL-10 and IL-1RA were significantly associated with disease severity, and a combination of CCL5, IL-1Ra and IL-10 at week 1 may predict patient outcomes. The majority of cytokines that are known to be associated with the cytokine storm in virus infections such as IL-6 and IFN-gamma were only significantly elevated in the late stage of severe COVID-19 illness. TNF- alpha and GM-CSF showed no significant differences between severe and mild cases. Conclusion Together our data suggest early intervention to increase expression of CCL5 may prevent patients from developing severe illness. Our data also suggest that measurement of levels of CCL5, as well as IL-1Ra, IL-10 in blood individually and in combination might be useful prognostic bio-markers to guide treatment strategies.
Yan Zhao, Ling Qin, Ping Zhang, Kang Li, Lianchun Liang, Jianping Sun, Bin Xu, Yanchao Dai, Xuemei Li, Chi Zhang, Yanchun Peng, Yingmei Feng, Ang Li, Zhongjie Hu, Haiping Xiang, Graham Ogg, Ling-Pei Ho, Andrew J. McMichael, Ronghua Jin, Julian C. Knight, Tao Dong, Yonghong Zhang
BACKGROUND. Dysregulation of L-arginine metabolism has been proposed to occur in severe asthma patients. The effects of L-arginine supplementation on L-arginine metabolite profiles in these patients is unknown. We hypothesized that severe asthmatics with low fractional exhaled nitric oxide (FeNO) would have fewer asthma exacerbations with the addition of L-arginine to their standard asthma medications compared to placebo and would demonstrate the greatest changes in metabolite profiles. METHODS. Participants were enrolled in a single-center, cross-over, double-blinded, L-arginine intervention trial at the University of California-Davis (NCT01841281). Subjects received placebo or L-arginine, dosed orally at 0.05mg/kg (ideal body weight) twice daily. The primary endpoint was moderate asthma exacerbations. Longitudinal plasma metabolite levels were measured using mass spectrometry. A linear mixed-effect model with subject-specific intercepts was used for testing treatment effects. RESULTS. A cohort of 50 subjects was included in the final analysis. L-arginine did not significantly decrease asthma exacerbations in the overall cohort. Higher citrulline levels and a lower arginine availability index (AAI) were associated with higher FeNO (P-value = 0.005 and 2.51 x 10–9 respectively). Higher AAI was associated with lower exacerbation events. The eicosanoid prostaglandin H2 (PGH2) and Nα-Acetyl-L-arginine were found to be good predictors for differentiating clinical responders and non-responders. CONCLUSIONS. There was no statistically significant decrease in asthma exacerbations in the overall cohort with L-arginine intervention. PGH2, Nα-Acetyl-L-arginine and the AAI could serve as predictive biomarkers in future clinical trials that intervene in the arginine metabolome.
Shu-Yi Liao, Megan R. Showalter, Angela L. Linderholm, Lisa M. Franzi, Celeste Kivler, Yao Li, Michael R. Sa, Zachary A. Kons, Oliver Fiehn, Lihong Qi, Amir A. Zeki, Nicholas J. Kenyon
The mechanisms of CAR-T cell mediated anti-tumor immunity and toxicity remain poorly characterized due to few studies examining the intact tumor microenvironment (TME) following CAR T-cell infusion. Axicabtagene ciloleucel is an autologous anti-CD19 chimeric antigen receptor (CAR) T-cell therapy approved for patients with large B-cell lymphoma. We devised multiplex immunostaining and in-situ hybridization assays to interrogate CAR T cells and other immune cell infiltrates in biopsies of diffuse large B-cell lymphoma following axicabtagene ciloleucel infusion. We found a majority of intratumoral CAR T cells expressed markers of T-cell activation but, unexpectedly, comprised ≤ 5% of all T cells within the TME five days or more after therapy. T cells lacking CAR (non-CAR T cells) were also activated within the TME after axicabtagene ciloleucel infusion, being positive for Ki-67, interferon-γ, granzyme B and/or PD-1, and highest in biopsies with CAR T cells. Additionally, non-CAR immune cells were the exclusive source of IL-6, a cytokine associated with cytokine release syndrome, and highest in biopsies with CAR T cells. These data indicate that intratumoral CAR T cells are associated with generalized immune cell activation within the TME with both beneficial and pathological effects.
Pei-Hsuan Chen, Mikel Lipschitz, Jason L. Weirather, Caron Jacobson, Philippe Armand, Kyle Wright, F. Stephen Hodi, Zachary J. Roberts, Stuart A. Sievers, John Rossi, Adrian Bot, William Y. Go, Scott J. Rodig
Heterotopic ossification (HO) is defined as abnormal differentiation of local stromal cells of mesenchymal origin resulting in pathologic cartilage and bone matrix deposition. CCN family members are matricellular proteins that have diverse regulatory functions on cell proliferation and differentiation, including the regulation of chondrogenesis. However, little is known regarding CCN family member expression or function in HO. Here, a combination of bulk and single cell RNA sequencing defined the dynamic temporospatial pattern of CCN family member induction within a mouse model of trauma-induced HO. Among CCN family proteins, Wisp1(also known as Ccn4) was most upregulated during the evolution of HO, and Wisp1 expression corresponded with chondrogenic gene profile. Immunohistochemistry confirmed WISP1/CCN4 expression across traumatic and genetic HO mouse models, as well as in human HO samples. Transgenic Wisp1LacZ/LacZ knockin animals showed an increase in endochondral ossification in HO after trauma. Finally, the transcriptome of Wisp1 null tenocytes revealed enrichment in signaling pathways such as STAT3 and PCP signaling that may explain increased HO in the context of Wisp1 deficiency. In sum, CCN family members, and in particular Wisp1, are spatiotemporally associated with and negatively regulate trauma-induced HO formation.
Ginny Ching-Yun Hsu, Simone Marini, Stefano Negri, Yiyun Wang, Jiajia Xu, Chase A. Pagani, Charles Hwang, David M. Stepien, Carolyn A. Meyers, Sarah Miller, Edward McCarthy, Karen M. Lyons, Benjamin Levi, Aaron W. James
Rheumatoid arthritis (RA) is characterized by synovial joint inflammation, cartilage damage and dysregulation of the adaptive immune system. While neutrophil extracellular traps (NETs) have been proposed to play a role in the generation of modified autoantigens and in the activation of synovial fibroblasts, it remains unknown whether NETs are directly involved in cartilage damage. Here, we report a new mechanism by which NET-derived elastase disrupts cartilage matrix and induces release membrane-bound peptidylarginine deiminase-2 (PAD2) by fibroblast-like synoviocytes (FLS). Cartilage fragments are subsequently citrullinated, internalized by FLS, and then presented to antigen-specific CD4+ T cells. Furthermore, immune-complexes containing citrullinated cartilage components can activate macrophages to release pro-inflammatory cytokines. HLA-DRB1*04:01 transgenic mice immunized with NETs develop autoantibodies to citrullinated cartilage proteins and display enhanced cartilage damage. Inhibition of NET-elastase rescues NET-mediated cartilage damage. These results show that NETs and neutrophil elastase externalized in these structures play fundamental pathogenic roles in promoting cartilage damage and synovial inflammation. Strategies targeting neutrophil elastase and NETs could have a therapeutic role in RA and in other inflammatory diseases associated with inflammatory joint damage.
Carmelo Carmona-Rivera, Philip M. Carlucci, Rishi R. Goel, Eddie A. James, Stephen R. Brooks, Cliff R. Rims, Victoria Hoffmann, David A. Fox, Jane H. Buckner, Mariana J. Kaplan
Whole sporozoite vaccines engender sterilizing immunity against malaria in animal models and importantly, in humans. Gene editing allows for the removal of specific parasite genes, enabling generation of genetically attenuated parasite (GAP) strains for vaccination. Using rodent malaria parasites, we have previously shown that late liver stage-arresting replication-competent (LARC) GAPs confer superior protection when compared to early liver stage-arresting replication-deficient (EARD) GAPs and radiation-attenuated sporozoites. However, generating a LARC GAP in the human malaria parasite Plasmodium falciparum (Pf) has been challenging. Here we report the generation and characterization of an unprecedented Pf LARC GAP generated by targeted gene deletion of the Mei2 gene; Pf mei2–. Robust exoerythrocytic schizogony with extensive cell growth and DNA replication was observed for Pf mei2- liver stages in human liver-chimeric mice. However, Pf mei2– liver stages failed to complete development and did not form infectious exo-erythrocytic merozoites, thereby preventing their transition to asexual blood stage infection. Therefore, Pf mei2– is a replication-competent, attenuated human malaria parasite strain with potentially increased potency, useful for vaccination to protect against Pf malaria infection.
Debashree Goswami, William Betz, Navin K. Locham, Chaitra Parthiban, Carolyn Brager, Carola Schäfer, Nelly Camargo, Thao Nguyen, Spencer Y. Kennedy, Sean C. Murphy, Ashley M. Vaughan, Stefan H.I. Kappe
Acute gastrointestinal Graft-versus-Host-Disease (GVHD) is a primary determinant of mortality after allogeneic hematopoietic stem-cell transplantation (alloSCT). It is mediated by alloreactive donor CD4+ T cells that differentiate into pathogenic subsets expressing IFNγ, IL-17A or GM-CSF, and is regulated by subsets expressing IL-10 and/or Foxp3. Developmental relationships between T-helper states during priming in mesenteric lymph nodes (mLN) and effector function in the GI tract remain undefined at genome-scale. We applied scRNA-seq and computational modelling to a mouse model of donor DC-mediated GVHD exacerbation, creating an atlas of putative CD4+ T-cell differentiation pathways in vivo. Computational trajectory inference suggested emergence of pathogenic and regulatory states along a single developmental trajectory in mLN. Importantly, we inferred an unexpected second trajectory, categorised by little proliferation or cytokine expression, reduced glycolysis, and high tcf7 expression. TCF1hi cells upregulated α4β7 prior to gut migration and failed to express cytokines therein. Nevertheless, they exhibited recall potential and plasticity following secondary transplantation, including cytokine or Foxp3 expression, but reduced TCF1. Thus, scRNA-seq suggested divergence of allo-reactive CD4+ T cells into quiescent and effector states during gut GVHD exacerbation by donor DC, reflecting putative heterogenous priming in vivo. These findings, the first at a single-cell level during GVHD over time, may assist in examination of T cell differentiation in patients undergoing alloSCT.
Jessica A. Engel, Hyun Jae Lee, Cameron G. Williams, Rachel D. Kuns, Stuart Olver, Lianne I.M. Lansink, Megan S.F. Soon, Stacey B. Andersen, Joseph E. Powell, Valentine Svensson, Sarah A. Teichmann, Geoffrey R. Hill, Antiopi Varelias, Motoko Koyama, Ashraful Haque
Chronic kidney disease is the main cause of mortality in patients with tuberous sclerosis complex disease (TSC). The mechanisms underlying TSC cystic kidney disease remain unclear with no available interventions to prevent cyst formation. Using targeted deletion of TSC1 in nephron progenitor cells, we showed that cysts in TSC1 null embryonic kidneys originate from injured proximal tubular cells with high mTOR complex 1 activity. Injection of rapamycin to pregnant mice inhibited the mTOR pathway and tubular cell proliferation in kidneys of TSC1 null offspring. Rapamycin also prevented renal cystogenesis and prolonged the life span of TSC newborns. Gene expression analysis of proximal tubule cells, identified sets of genes and pathways that were modified secondary to TSC1 deletion and rescued by rapamycin administration during nephrogenesis. Inflammation with mononuclear infiltration was observed in the cystic areas of TSC1 null kidneys. Dexamethasone administration during pregnancy decreased cyst formation not only by inhibiting the inflammatory response but also by interfering with the mTORC1 pathway. These results reveal novel mechanisms of cystogenesis in TSC disease and suggest new interventions prior to birth to ameliorate cystic disease in offspring.
Morris Nechama, Yaniv Makayes, Elad Resnick, Karen Meir, Oded Volovelsky
Scleraxis is a basic helix-loop-helix transcription factor that plays a central role in promoting tenocyte proliferation and matrix synthesis during embryonic tendon development. However, the role of scleraxis in the growth and adaptation of adult tendons is not known. We hypothesized that scleraxis is required for tendon growth in response to mechanical loading, and that scleraxis promotes the specification of progenitor cells into tenocytes. We conditionally deleted scleraxis in adult mice using a tamoxifen-inducible Cre-recombinase expressed from the Rosa26 locus (ScxΔ), and then induced tendon growth in Scx+ and ScxΔ adult mice via plantaris tendon mechanical overload. Compared to the wild type Scx+ group, ScxΔ mice demonstrated blunted tendon growth. Transcriptional and proteomic analyses revealed significant reductions in cell proliferation, protein synthesis, and extracellular matrix genes and proteins. Our results indicate that scleraxis is required for mechanically-stimulated adult tendon growth by causing the commitment of CD146+ pericytes into the tenogenic lineage, and by promoting the initial expansion of newly committed tenocytes and the production of extracellular matrix proteins.
Jonathan P. Gumucio, Martin M. Schonk, Yalda A. Kharaz, Eithne Comerford, Christopher L. Mendias
Mesenchymal stem/stromal cells (MSCs) regulate immunity through myeloid-derived suppressor cells (MDSCs) which are a heterogeneous population of immature myeloid cells with phenotypic and functional diversity. Herein, we identified a distinct subset of MDSCs induced by MSCs in the BM under inflammatory conditions. MSCs directed the differentiation of Ly6Glo BM cells from CD11bhiLy6Chi to CD11bmidLy6Cmid cells both in cell contact-independent and -dependent manners upon GM-CSF stimulation in vitro and in mice with experimental autoimmune uveoretinitis (EAU). RNA sequencing indicated that MSC-induced CD11bmidLy6CmidLy6Glo cells had a distinct transcriptome profile from CD11bhiLy6ChiLy6Glo cells. Phenotypic, molecular, and functional analyses showed that CD11bmidLy6CmidLy6Glo cells differed from CD11bhiLy6ChiLy6Glo cells by low expression of MHC class II, co-stimulatory molecules, and pro-inflammatory cytokines, high production of immunoregulatory molecules, indifference to LPS, and inhibition of T cell proliferation and activation. Consequently, adoptive transfer of MSC-induced CD11bmidLy6CmidLy6Glo cells significantly attenuated the development of EAU in mice. Further mechanistic study revealed that suppression of prostaglandin E2 (PGE2) and HGF secretion in MSCs by siRNA transfection partially reversed the effects of MSCs on MDSC differentiation. Altogether, data demonstrate that MSCs drive the differentiation of BM cells toward CD11bmidLy6CmidLy6Glo MDSCs in part through HGF and COX-2/PGE2, leading to resolution of ocular autoimmune inflammation.
Hyun Ju Lee, Jung Hwa Ko, Hyeon Ji Kim, Hyun Jeong Jeong, Joo Youn Oh
The mortality of patients suffering from acute myocardial infarction (AMI) is linearly related to the infarct size. As regeneration of cardiomyocytes from cardiac progenitor cells is minimal in the mammalian adult heart, we have explored a new therapeutic approach which leverages the capacity of nanomaterials to release chemicals over time to promote myocardial protection and infarct size reduction. Initial screening identified two chemicals, FGF1 and CHIR99021 (a Wnt1 agonist/GSK-3ß antagonist) which synergistically enhance cardiomyocyte cell cycle in vitro. Poly-lactic-co-glycolic acid (PLGA) nanoparticles (NP) formulated with CHIR99021 and FGF1 (CHIR+FGF1-NPs) provided an effective slow release system for up to 4 weeks. Intramyocardial injection of CHIR+FGF1-NPs enabled myocardial protection via reducing infarct size by 20% to 30% in mouse or pig models of postinfarction LV remodeling. This LV structural improvement was accompanied by a significant preservation of cardiac contractile function. Further investigation revealed that CHIR+FGF1-NPs resulted in a significant reduction of cardiomyocyte apoptosis and increase of angiogenesis. Thus, using a combination of chemicals and a NP-based prolonged release system that work synergistically, this study demonstrates a novel therapy for LV infarct size reduction in hearts with acute myocardial infarction.
Chengming Fan, Yasin Oduk, Meng Zhao, Xi Lou, Yawen Tang, Danielle Pretorius, Mani T. Valarmathi, Gregory P. Walcott, Jingfu Yang, Philippe Menasche, Prasanna Krishnamurthy, Wuqiang Zhu, Jianyi Zhang
Alopecia areata (AA) is one of the most common autoimmune conditions, presenting initially with loss of hair without other overt skin changes. The unremarkable appearance of the skin surface contrasts with the complex immune activity occurring at the hair follicle. AA pathogenesis is due to the loss of immune privilege of the hair follicle leading to autoimmune attack. Although the literature has focused on CD8+ T cells, vital roles for CD4+ T cells and antigen-presenting cells have been suggested. Here, we use single-cell sequencing to reveal distinct expression profiles of immune cells in murine AA. We found clonal expansions of both CD4+ and CD8+ T cells, with shared clonotypes across varied transcriptional states. The murine AA data were used to generate highly predictive models of human AA disease. Finally, single-cell sequencing of T cells in human AA recapitulated the clonotypic findings and the gene expression of the predictive models.
Nicholas Borcherding, Sydney B. Crotts, Luana S. Ortolan, Nicholas Henderson, Nicholas L. Bormann, Ali Jabbari
Background: HVTN 098, a randomized, double-blind, placebo-controlled trial, evaluated the safety, tolerability and immunogenicity of PENNVAX®-GP HIV DNA vaccine, administered with or without plasmid IL-12 (pIL-12), via intradermal (ID) or intramuscular (IM) electroporation (EP) in healthy, HIV-uninfected adults. The study tested whether PENNVAX®-GP delivered via ID/EP at 1/5th the dose could elicit equivalent immune responses to delivery via IM/EP, and if inclusion of pIL-12 provided additional benefit. Methods: Participants received DNA encoding HIV-1 env/gag/pol in three groups: 1.6mg ID (ID no IL-12 group, n=20), 1.6mg ID + 0.4mg pIL-12 (ID+IL-12 group, n=30), 8mg IM + 1mg pIL-12 (IM+IL-12 group, n=30) or placebo (n=9) via EP at 0, 1, 3 and 6 months. Results of cellular and humoral immunogencity assessments are reported. Results: Following vaccination, the frequency of responders (response rate) to any HIV protein based on CD4+ T-cells expressing IFN-γ and/or IL-2 was 96% for both the ID+IL-12 and IM+IL-12 groups; CD8+ T-cell response rates were 64% and 44%, respectively. For ID delivery, the inclusion of pIL-12 increased CD4+ T-cell response rate from 56% to 96%. The frequency of responders was similar (>90%) for IgG binding Ab to gp140 consensus Env across all groups, but the magnitude was higher in the ID+IL-12 group compared to the IM+IL-12 group. Conclusion: PENNVAX®-GP DNA induced robust cellular and humoral immune responses, demonstrating that immunogenicity of DNA vaccines can be enhanced by EP route and inclusion of pIL-12. ID/EP was dose-sparing, inducing equivalent, or in some aspects superior, immune responses compared to IM/EP. Trial registration: ClinicalTrials.gov NCT02431767 Funding: This work was supported by the National Institute of Allergy and Infectious Diseases (NIAID, https://www.niaid.nih.gov/) U.S. Public Health Service Grants UM1 AI068618 [LC: HIV 75 Vaccine Trials Network], UM1 AI068614 [LOC: HIV Vaccine Trials Network], UM1 AI068635 76 [SDMC: HIV Vaccine Trials Network], , U01 AI069418-ˇ08 [Emory-ˇCDC Clinical Trials Unit], UM AI069511 [University of Rochester HIV/AIDS Clinical Trials Unit], UM1 AI069439 77 [Vanderbilt Clinical Trial Unit], UM1 AI069481 [Seattle-ˇLausanne Clinical Trials Unit] and HVDDT Contract HHSN2722008000063C (Inovio Pharmaceuticals). This work was also supported, in part, by IPCAVD award U19 AI09646-ˇ03 (DBW) and NIH award P01 AI120756 (GDT). The opinions expressed in this article are those of the authors and do not necessarily represent the official views of the NIAID or the National Institutes of Health (NIH).
Stephen DeRosa, Srilatha Edupuganti, Yunda Huang, Xue Han, Marnie Elizaga, Edith Swann, Laura Polakowski, Spyros A. Kalams, Michael C. Keefer, Janine Maenza, Yiwen Lu, Megan C. Wise, Jian Yan, Matthew P. Morrow, Amir S. Khan, Jean Boyer, Laurent M. Humeau, Scott White, Michael N. Pensiero, Niranjan Y. Sardesai, Mark Bagarazzi, David B. Weiner, Guido Ferrari, Georgia Tomaras, David Montefiori, Lawrence Corey, M. Juliana McElrath
Acute graft versus host disease (aGvHD) remains a major impediment to successful allogeneic hematopoietic cell transplantation (allo-HCT). To solve this problem, a greater knowledge of factors which regulate the differentiation of donor T cells toward cytotoxic or regulatory cells is necessary. We report that the β2-adrenergic receptor (β2-AR) is critical for regulating this differentiation, and that its manipulation can control aGvHD without impairing the graft-versus-tumor (GvT) effect. Donor T cell β2-AR expression and signaling is associated with decreased aGvHD when compared to recipients of β2-AR–/– donor T cells. We determined that β2-AR activation skewed CD4+ T cell differentiation in vitro and in vivo toward regulatory T cells (Tregs) rather than the T helper 1 (Th1) phenotype. Treatment of allo-HCT recipients with a selective β2-agonist, (bambuterol) ameliorated aGvHD severity. This was associated with increased Tregs, decreased cytotoxic T cells, and increased donor bone marrow-derived myeloid derived suppressor cells (MDSCs) in allogeneic and humanized xenogeneic aGvHD models. β2-AR signaling resulted in increased Treg generation through glycogen synthase kinase-3 activation. Bambuterol preserved the GvT effect by inducing NKG2D+ effector cells and central memory T cells. These data reveal how β-AR signaling can be targeted to ameliorate GvHD severity while preserving GvT effect.
Hemn Mohammadpour, Joseph L. Sarow, Cameron R. MacDonald, George L. Chen, Jingxin Qiu, Umesh C. Sharma, Xuefang Cao, Megan M. Herr, Theresa E. Hahn, Bruce R. Blazar, Elizabeth A. Repasky, Philip L. McCarthy
Abnormal subretinal neovascularization is characteristic of vision-threatening retinal diseases including macular telangiectasia (MacTel) and retinal angiomatous proliferation (RAP). Subretinal neovascular tufts and photoreceptor dysfunction are observed in very low-density lipoprotein receptor mutant mice (Vldlr–/–). These changes mirror those observed in MacTel and RAP patients, but the pathogenesis is largely unknown. In this study, we show that retinal microglia are closely associated with retinal neovascular tufts in Vldlr–/– mice and retinal tissue from MacTel patients; ablation of microglia/macrophages dramatically prevents formation of retinal neovascular tufts and improves neuronal function as assessed by electroretinography. VMD2-driven retinal pigmented epithelium (RPE)-specific knockouts of VEGF greatly reduced subretinal infiltration of microglia/macrophages, subsequently reducing NV tufts. These findings highlight the contribution of microglia/macrophages to the pathogenesis of NV, provide valuable clues regarding potential causative cellular mechanisms for subretinal neovascularization in MacTel and RAP patients, and suggest that targeting microglia activation may be a therapeutic option in these diseases.
Ayumi Usui-Ouchi, Yoshihiko Usui, Toshihide Kurihara, Edith Aguilar, Michael I. Dorrell, Yoichiro Ideguchi, Susumu Sakimoto, Stephen Bravo, Martin Friedlander
In pulmonary hypertension and certain forms of congenital heart disease, ventricular pressure overload manifests at birth and is an obligate hemodynamic abnormality that stimulates myocardial fibrosis which leads to ventricular dysfunction and poor clinical outcomes. Thus, an attractive strategy is to attenuate the myocardial fibrosis to help preserve ventricular function. Here, by analyzing RNA-sequencing databases and comparing the transcript and protein levels of fibrillar collagen in wild-type and global knockout mice, we found that SLIT3 was predominantly present in fibrillar collagen-producing cells and that SLIT3 deficiency attenuated collagen production in the heart and other non-neuronal tissues. We then performed transverse aortic constriction or pulmonary artery banding in wild-type and knockout mice to induce left and right ventricular pressure overload, respectively. We discovered that SLIT3 deficiency abrogates fibrotic and hypertrophic changes and promotes long-term ventricular function and overall survival in both left and right ventricular pressure overload. Furthermore, we found that SLIT3 stimulated fibroblast activity and fibrillar collagen production, which coincided with the transcription and nuclear localization of the mechanotransducer YAP1. These results indicate that SLIT3 is important for regulating fibroblast activity and fibrillar collagen synthesis in an autocrine manner, making it a potential therapeutic target for fibrotic diseases, especially myocardial fibrosis and adverse remodeling induced by persistent afterload elevation.
Lianghui Gong, Shuyun Wang, Li Shen, Catherine Liu, Mena Shenouda, Baolei Li, Xiaoxiao Liu, John Shaw, Alan Wineman, Yifeng Yang, Dingding Xiong, Anne Eichmann, Sylvia M. Evans, Stephen J. Weiss, Ming-Sing Si
The SIRPα-CD47 interaction provides a macrophage immune checkpoint pathway that plays a critical role in cancer immune evasion across multiple cancers. Here, we report the engineering of a humanized anti-SIRPα monoclonal antibody (1H9) for antibody target cancer therapy. 1H9 has broad activity across a wide range of SIRPα variants. Binding of 1H9 to SIRPα blocks its interaction with CD47, thereby promoting macrophage-mediated phagocytosis of cancer cells. Pre-clinical studies in vitro and in vivo demonstrate that 1H9 synergizes with other therapeutic antibodies to promote phagocytosis of tumor cells and inhibit tumor growth in both syngeneic and xenograft tumor models, leading to survival benefit. Thus, 1H9 can potentially act as a universal agent to enhance therapeutic efficacy when used in combination with most tumor-targeting antibodies. We report for the first time, a comparison of anti-SIRPα and anti-CD47 antibodies in CD47/SIRPα double humanized mice, and found that 1H9 exhibits a substantially reduced antigen-sink effect due to the limited tissue distribution of SIRPα expression. Toxicokinetic studies in non-human primates show that 1H9 is well tolerated with no treatment-related adverse effects noted. These data highlight the clinical potential of 1H9 as a pan-therapeutic with the desired properties when used in combination with tumor-targeting antibodies.
Jie Liu, Seethu Xavy, Shirley Mihardja, Sharline Chen, Kavitha Sompalli, Dongdong Feng, Timothy S. Choi, Balaji Agoram, Ravindra Majeti, Irving L. Weissman, Jens-Peter Volkmer