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Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.135449.
Abstract
The specificity of antibodies (Abs) generated to influenza A virus (IAV) infection can significantly alter protection and viral clearance. At present, the impact of age upon this process is relatively unexplored. Here, we evaluated the Ab response in newborn and adult African green monkeys (AGM) following infection with IAV using a strain that enables us to determine the immunodominance (ID) hierarchy of the Ab response to hemagglutinin (HA), the principal target of protective Abs. This revealed altered ID patterns in the early IgM anti-HA response in newborns versus adults that converged over time. While the IgG ID profiles for HA in newborn and adult monkeys were similar, this was not the case for IgA. Importantly, HA stem-specific Abs were generated robustly and similarly in newborns and adults in terms of quality and quantity. Together these results demonstrate that newborns and adults can differ in the Ab ID pattern established following infection and that the ID pattern can vary across isotypes. In addition, newborns have the ability to generate potent HA stem-specific Ab responses. Our findings further the understanding of the newborn response to IAV antigens and inform the development of improved vaccines for this at-risk population.
Authors
Elene A. Clemens, Davide Angeletti, Beth C. Holbrook, Masaru Kanekiyo, Matthew J. Jorgensen, Barney S. Graham, Jonathan W. Yewdell, Martha A. Alexander-Miller
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.134061.
Abstract
The blood hormone erythropoietin (EPO), upon binding to its receptor (EpoR), modulates high fat-diet (HFD)-induced obesity in mice, improves glucose tolerance, and prevents white adipose tissue inflammation. Transgenic mice with constitutive over-expression of human EPO solely in brain (Tg21) were used to assess the neuro-endocrine EPO effect without increasing the hematocrit. Male Tg21-mice resisted HFD-induced weight gain, showed lower serum ACTH, corticosterone and C-reactive protein levels, and prevented myeloid cell recruitment to hypothalamus compared with WT-males. HFD-induced hypothalamic inflammation (HI) and microglial activation were higher in male mice, and Tg21-males exhibited lower increase in HI than WT-males. Physiological EPO function in the brain also showed sexual dimorphism in regulating HFD response. Targeted deletion of EpoR gene expression in neuronal and glial cells worsened HFD-induced glucose intolerance in both male and female mice, but increased weight gain and HI in the hypothalamus in male mice only. Female estrogen production blocked reduced weight gain and HI. Both male and female Tg21-mice kept on normal-chow and HFD showed significantly improved glycemic control. Our data indicates that cerebral EPO regulates weight gain and HI in a sex-dependent response, distinct from EPO regulation of glycemic control, and independent of erythropoietic EPO response.
Authors
Soumyadeep Dey, Zhenzhong Cui, Oksana Gavrilova, XiaoJie Zhang, Max Gassmann, Constance T. Noguchi
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.127018.
Abstract
Most prostate cancers depend on androgens for growth and therefore the mainstay treatment for advanced, recurrent or metastatic prostate cancer is androgen deprivation therapy (ADT). A prominent side effect in patients receiving ADT is an obese frailty syndrome that includes fat gain and sarcopenia, defined as the loss of muscle function accompanied by reduced muscle mass or quality. Mice bearing Pten deficient prostate cancers were examined to gain mechanistic insight into ADT-induced sarcopenic obesity. Castration induced fat gain as well as skeletal muscle mass and strength loss. Catabolic TGFß-family myokine protein levels were increased immediately prior to strength loss and pan-myokine blockade using a soluble receptor (ActRIIB-Fc) completely reversed the castration-induced sarcopenia. The onset of castration-induced strength and muscle mass loss, as well as the increase in catabolic TGFß-family myokine protein levels, were coordinately accelerated in tumor-bearing mice relative to tumor-free mice. Notably, GDF11 increased in muscle after castration only in tumor-bearing mice, but not in tumor free mice. An early surge of GDF11 in prostate tumor tissue and in the circulation suggests that endocrine GDF11 signaling from tumor to muscle is a major driver of the accelerated ADT-induced sarcopenic phenotype. In tumor-bearing mice, GDF11 blockade largely prevented castration-induced strength loss but did not preserve muscle mass, which confirms a primary role for GDF11 in muscle function and suggests an additional role for the other catabolic myokines.
Authors
Chunliu Pan, Neha Jaiswal Agrawal, Yanni Zulia, Shalini Singh, Kai Sha, James L. Mohler, Kevin H. Eng, Joe Chakkalakal, John J. Krolewski, Kent L. Nastiuk
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.133113.
Abstract
We reported that transgenic mice expressing measles virus nucleocapsid protein (MVNP) in OCLs (MVNP mice) are a Paget’s disease (PD) model, and that osteoclasts (OCLs) from PD patients and MVNP mice express high levels of OCL-derived IGF1 (OCL-IGF1). To determine OCL-IGF1’s role in PD and normal bone remodeling, we generated WT and MVNP mice with targeted deletion of Igf1 in OCLs (Igf1-cKO) and MVNP/Igf1-cKO mice and assessed OCL-IGF1’s effects on bone mass, bone formation rate, ephrinB2/EphB4 expression on OCLs and osteoblasts (OBs) and pagetic bone lesions (PDLs). Forty percent of MVNP mice but no MVNP/Igf1-cKO mice had PDLs. BV/TV was decreased 60% in lumbar vertebrae and femurs of MVNP/Igf1-cKO vs. MVNP mice with PDLs and by 45% vs. all MVNP mice tested. Bone formation rates were decreased 50% in Igf1-cKO and MVNP/Igf1-cKO mice vs. WT and MVNP mice. MVNP mice had increased ephrinB2 and EphB4 levels in OCLs/OBs vs. WT and MVNP/Igf1-cKO, with none detectable in OCLs/OBs of Igf1-cKO mice. Mechanistically, IL-6 induced the increased OCL-IGF1 in MVNP mice. These results suggest that high OCL-IGF1 levels increase bone formation and PDLs in PD by enhancing ephrinB2/EphB4 expression in vivo, and that OCL-IGF1 may possibly contribute to normal bone remodeling.
Authors
Kazuaki Miyagawa, Yasuhisa Ohata, Jesus Delgado-Calle, Jumpei Teramachi, Hua Zhou, David W. Dempster, Mark A. Subler, Jolene J. Windle, John Chirgwin, G. David Roodman, Noriyoshi Kurihara
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.92385.
Abstract
Long-term memory depends on the control of activity-dependent neuronal gene expression, which is regulated by epigenetic modifications. The epigenetic modification of histones is orchestrated by the opposing activities of two classes of regulatory complexes: permissive co-activators and silencing co-repressors. Much work has focused on co-activator complexes, but little is known about the co-repressor complexes that suppress the expression of plasticity-related genes. Here, we define a critical role for the co-repressor SIN3A in memory and synaptic plasticity, showing that postnatal neuronal deletion of Sin3a enhances hippocampal long-term potentiation and long-term contextual fear memory. SIN3A regulates the expression of genes encoding proteins in the post-synaptic density. Loss of SIN3A increases expression of the synaptic scaffold Homer1, alters the mGluR1α- and mGluR5-dependence of long-term potentiation, and increases activation of extracellular signal regulated kinase (ERK) in the hippocampus after learning. Our studies define a critical role for co-repressors in modulating neural plasticity and memory consolidation and reveal that Homer1/mGluR signaling pathways may be central molecular mechanisms for memory enhancement.
Authors
Morgan S. Bridi, Hannah Schoch, Cédrick Florian, Shane G. Poplawski, Anamika Banerjee, Joshua D. Hawk, Giulia S. Banks, Camille Lejards, Chang-Gyu Hahn, Karl Peter Giese, Robbert Havekes, Nelson Spruston, Ted Abel
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.132306.
Abstract
A critical component of wound healing is the transition from the inflammatory phase to the proliferation phase to initiate healing and remodeling of the wound. Macrophages are critical for the initiation and resolution of the inflammatory phase during wound repair. In diabetes, macrophages display a sustained inflammatory phenotype in late wound healing characterized by elevated production of inflammatory cytokines such as TNFα. Previous studies have shown that an altered epigenetic program directs diabetic macrophages towards a pro-inflammatory phenotype contributing to a sustained inflammatory phase. Males absent on the first (MOF) is a histone acetyl-transferase (HAT) that has been shown be a co-activator of TNFα-signaling and promote NFκB-mediated gene transcription in prostate cancer cell lines. Based on MOFs role in TNFα/NFκB-mediated gene expression, we hypothesized that MOF influences macrophage-mediated inflammation during wound repair. We used a myeloid-specific Mof knockout (Lyz2Cre Moff/f) and diet-induced obese (DIO) mice, to determine the function of MOF in diabetic wound healing. MOF deficient mice exhibited reduced inflammatory cytokine gene expression. Furthermore, we found that wound macrophages from DIO mice had elevated MOF levels and higher levels of acetylated histone H4K16, MOFs primary substrate of HAT activity, on the promoters of inflammatory genes. We further identified that MOF expression could by stimulated by TNFα and that treatment with Etanercept, an FDA-approved TNFα inhibitor, reduced MOF levels and improved wound healing in DIO mice. This report is the first to define an important role for MOF in regulating macrophage-mediated inflammation in wound repair and identifies TNFα-inhibition as a potential therapy for the treatment of chronic inflammation in diabetic wounds.
Authors
Aaron D. denDekker, Frank M. Davis, Amrita D. Joshi, Sonya J. Wolf, Ronald Allen, Jay Lipinski, Brenda Nguyen, Joseph Kirma, Dylan Nycz, Jennifer R. Bermick, Bethany B. Moore, Johann E. Gudjonsson, Steven L. Kunkel, Katherine A. Gallagher
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.132364.
Abstract
Maintaining cellular proteostasis is essential for oligodendrocyte viability and function; however, its underlying mechanisms remain unexplored. The UPR, comprising three parallel branches IRE1, PERK, and ATF6α, is a major mechanism that maintains cellular proteostasis by facilitating protein folding, attenuating protein translation, and enhancing autophagy and ERAD. Here we reported that impaired UPR in oligodendrocytes via deletion of PERK and ATF6α did not affect developmental myelination, but caused late-onset mature oligodendrocyte dysfunction and death in young adult mice. The detrimental effects of the impaired UPR on mature oligodendrocytes were accompanied by autophagy impairment and intracellular PLP accumulation, and were rescued by PLP deletion. Data indicate that PLP is degraded by autophagy and that intracellular PLP accumulation is cytotoxic to oligodendrocytes. Thus, these findings imply that the UPR is required for maintaining cellular proteostasis and the viability and function of mature oligodendrocytes in adults by regulating autophagy of PLP.
Authors
Sarrabeth Stone, Shuangchan Wu, Klaus-Armin Nave, Wensheng Lin
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.94035.
Abstract
Development of gastric cancer is often preceded by chronic inflammation, but the immune cellular mechanisms underlying this process are unclear. Here we demonstrated that an inflammasome molecule, absent in melanoma 2 (Aim2), was upregulated in gastric cancer patients, and in spasmolytic polypeptide-expressing metaplasia (SPEM) of chronically Helicobacter felis (H. felis)-infected stomachs in mice. However, we found that Aim2 was not necessary for inflammasome function during gastritis. In contrast, Aim2 deficiency led to an increase in gastric CD8+ T cell frequency, which exacerbated metaplasia. These gastric CD8+ T cells from Aim2-/- mice were found to have lost their homing receptor expression (S1pr1 and CD62l), a feature of tissue resident memory T cells (TRM). The process was not mediated by Aim2-dependent regulation of IFN-β, or by dendritic cell-intrinsic Aim2. Rather, Aim2 deficiency contributed to an increased production of Cxcl16 by B cells, which could suppress S1pr1 and CD62l in CD8+ T cells. The study describes a novel function of Aim2 that regulates CD8+ T cell infiltration and retention within chronically inflamed solid organ tissue. This function operates independently of the inflammasome, IFN-β or dendritic cells. We provide evidence that B cells can contribute to this mechanism via Cxcl16.
Authors
Mohamad El-Zaatari, Shrinivas Bishu, Min Zhang, Helmut Grasberger, Guoqing Hou, Henry R. Haley, Brock A. Humphries, Li-Jyun Syu, Andrzej Dlugosz, Kathryn E. Luker, Gary Luker, Kathryn A. Eaton, Nobuhiko Kamada, Marilia Cascalho, John Y. Kao
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.130751.
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 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 two cancer-associated fibroblasts (CAFs) that either express (CD146pos) or lack (CD146neg) 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: CD146neg fibroblasts promote increased metastasis compared to CD146pos fibroblasts. Novel quantitative and qualitative proteomic analyses show that CD146pos CAFs produce an environment rich in basement membrane proteins, while CD146neg CAFs exhibit increases in FN1, LOX, and TNC; all over-expressed in aggressive disease. We also show clinically, that CD146neg CAFs predict for likelihood of lymph node involvement even in small primary tumors (<5 cm). Clearly small tumors enriched for CD146neg 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 C. Hansen, Peter Kabos
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.132997.
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 over several years. We used linear spline models with a knot at seven years; these included a random intercept and slope up to the knot. We also estimated the influence of covariates on starting levels and rates of change. RESULTS. We studied 81 individuals for a median of 7.3 (IQR 5.9–9.6) years. In a model allowing for a change in the rate of decline, we found evidence for a more rapid rate of decline in intact genomes from initial suppression through seven years (15.7% per year decline; CI –22.8%, –8.0%) followed by a slower rate of decline after seven years (3.6% per year; CI –8.1%, +1.1%). The estimated half-life of the reservoir was 4.0 years (CI 2.7–8.3) until year seven and 18.7 years (CI 8.2–infinite) thereafter. There was substantial variability between individuals in the rate of decline until year seven. Intact provirus declined at a faster rate than defective provirus (P < 0.001). Individuals with higher CD4+ T cell nadir values had a faster rate of decline in intact provirus. CONCLUSIONS. These findings provide evidence that 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. This work was supported the Delaney AIDS Research Enterprise (DARE; AI096109, A127966). The SCOPE cohort receives additional support from the UCSF/Gladstone Institute of Virology & Immunology CFAR (P30 AI027763), the CFAR Network of Integrated Systems (R24 AI067039) and the amfAR Institute for HIV Cure Research (amfAR 109301). Additional support was provided by the I4C and Beat-HIV Collaboratories, the Howard Hughes Medical Institute, Gilead, and the Bill and Melinda Gates Foundation.
Authors
Michael J. Peluso, Peter Bacchetti, Kristen D. Ritter, Subul A. Beg, Jun Lai, Jeffrey N. Martin, Peter W. Hunt, Timothy J. Henrich, Janet D. Siliciano, Robert F. Siliciano, Gregory M. Laird, Steven G. Deeks
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.130155.
Abstract
Altered bone marrow hematopoiesis and immune suppression is a hallmark of myelodysplastic syndrome (MDS). While the bone marrow microenvironment influences malignant hematopoiesis, the mechanism leading to MDS-associated immune suppression is unknown. We tested whether mesenchymal stromal cells (MSCs) contribute to this process. Here, we developed a model to study cultured MSCs from MDS patients compared to similar aged matched normal controls for regulation of immune function. MSCs from MDS patients (MDS-MSC) and healthy donor MSC (HD-MSC) exhibited a similar in vitro phenotype and neither had a direct effect on NK cell function. However, when MDS and HD-MSCs were cultured with monocytes, only the MDS-MSCs acquired phenotypic and metabolic properties of myeloid-derived suppressor cells (MDSCs), with resulting suppression of NK cell function, along with T cell proliferation. A unique MSC transcriptome was observed in MDS-MSCs compared to HD-MSCs, including increased expression of the reactive oxygen species (ROS) regulator, ENC1. High ENC1 expression in MDS-MSC induced suppressive monocytes with increased INHBA, a gene that encodes for a member of the TGFβ superfamily of proteins. These monocytes also had reduced expression of the TGFβ transcriptional repressor MAB21L2, further adding to their immune suppressive function. Silencing ENC1 or inhibiting ROS production in MDS-MSCs abrogated the suppressive function of MDS-MSC conditioned monocytes. In addition, silencing MAB21L2 in healthy MSC conditioned monocytes mimicked the MDS-MSC suppressive transformation of monocytes. Our data demonstrate that MDS-MSCs are responsible for inducing an immune suppressive microenvironment in MDS through an indirect mechanism involving monocytes.
Authors
Dhifaf Sarhan, Jinhua Wang, Upasana Sunil Arvindam, Caroline Hallstrom, Michael R. Verneris, Bartosz Grzywacz, Erica Warlick, Bruce R. Blazar, Jeffrey S. Miller
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.134172.
Abstract
Extracellular cold-inducible RNA-binding protein (eCIRP) is a recently-discovered damage-associated molecular pattern. Understanding the precise mechanism by which it exacerbates inflammation is essential. Here we identified that eCIRP is a new biologically active endogenous ligand of triggering receptor expressed on myeloid cells-1 (TREM-1), fueling inflammation in sepsis. Surface plasmon resonance revealed a strong binding affinity between eCIRP and TREM-1, and FRET assay confirmed eCIRP’s interaction with TREM-1 in macrophages. Targeting TREM-1 by its siRNA or a decoy peptide LP17 or by using TREM-1-/- mice dramatically reduced eCIRP-induced inflammation. We developed a novel 7-aa peptide derived from human eCIRP, M3, which blocked the interaction of TREM-1 and eCIRP. M3 suppressed inflammation induced by eCIRP or agonist TREM-1 Ab crosslinking in murine macrophages or human peripheral blood monocytes. M3 also inhibited eCIRP-induced systemic inflammation and tissue injury. Treatment with M3 further protected mice from sepsis, improved acute lung injury, and increased survival. Thus, we have discovered a novel TREM-1 ligand and developed a new peptide M3 to block the eCIRP-TREM-1 interaction and improve the outcomes in sepsis.
Authors
Naomi-Liza Denning, Monowar Aziz, Atsushi Murao, Steven D. Gurien, Mahendar Ochani, Jose M. Prince, Ping Wang
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.133715.
Abstract
Extracellular cold-inducible RNA-binding protein (eCIRP) is a damage-associated molecular pattern, whose effect on macrophages is not entirely elucidated. Here we identified that eCIRP promotes macrophage endotoxin tolerance. Septic mice had higher serum levels of eCIRP; this was associated with a reduced ex vivo immune response of their splenocytes to LPS. Pretreatment of macrophages with recombinant murine (rm) CIRP resulted in a tolerance to LPS stimulation as demonstrated by a significant reduction of TNF-α production. We found that eCIRP increased phosphorylation of STAT3 (pSTAT3) in macrophages. A STAT3 inhibitor, Stattic, rescued macrophages from rmCIRP-induced tolerance by restoring the release of TNF-α in response to LPS stimulation. We discovered strong binding affinity between eCIRP and IL-6R as revealed by Biacore, FRET, and their co-localization in macrophages by immunostaining assays. Blockade of IL-6R with its neutralizing Ab significantly inhibited eCIRP-induced pSTAT3 and restored LPS-stimulated TNF-α release in macrophages. Incubation of macrophages with rmCIRP skewed them towards a M2 phenotype, while treatment with anti-IL-6R Ab prevented rmCIRP-induced M2 polarization. Thus, we have demonstrated that eCIRP activates pSTAT3 via a novel receptor IL-6R to promote macrophage endotoxin tolerance. Targeting eCIRP appears to be a new therapeutic option to correct immune-tolerance in sepsis.
Authors
Mian Zhou, Monowar Aziz, Naomi-Liza Denning, Hao-Ting Yen, Gaifeng Ma, Ping Wang
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.134539.
Abstract
Recent studies have presented compelling evidence that it is not tissue-resident, but rather monocyte-derived alveolar macrophages (TR-AMs vs. Mo-AMs) are essential to development of experimental lung fibrosis. However, whether Apolipoprotein E (ApoE), which is produced abundantly by Mo-AMs in the lung, plays a role in the pathogenesis is unclear. In this study, we found that pulmonary ApoE was almost exclusively produced by Mo-AMs in mice with bleomycin induced lung fibrosis. We showed although ApoE was not necessary for developing maximal fibrosis in bleomycin injured lung, it was required for the resolution of this pathology. We found that ApoE directly bound to Collagen I and mediated Collagen I phagocytosis in vitro and in vivo, and this process was dependent on low density lipoprotein receptor-related protein 1 (LPR1). Furthermore, interference of ApoE/LRP1 interaction impaired the resolution of lung fibrosis in bleomycin treated wild-type mice. In contrast, supplementation of ApoE promoted this process in ApoE–/– animals. In conclusion, Mo-AM derived ApoE is beneficial to the resolution of lung fibrosis, supporting the notion that Mo-AMs may have distinct functions in different phases of lung fibrogenesis. The findings also suggest a novel therapeutic target for treating lung fibrosis, to which effective remedies remain scarce.
Authors
Huachun Cui, Dingyuan Jiang, Sami Banerjee, Na Xie, Tejaswini Kulkarni, Rui-Ming Liu, Steven R. Duncan, Gang Liu
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.134063.
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 novel 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 which 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
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.131494.
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 neuron and glia density, in Dlx1/2-/- or Dlx1-/- mice. However, RNA sequencing of Dlx1/2-/- ENS revealed dysregulation of many genes, including vasoactive intestinal peptide (Vip). Our study reveals 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
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.126268.
Abstract
Cell therapy raises high hopes 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 two distant embryonic SCs lines (H9 and RC17) to express one of four 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, three out of four 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 towards 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
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.133977.
Abstract
In recent years, 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 TGFβ receptor II (TGFBR2) in CAR-T cells with CRISPR/Cas9 technology could reduce the induced regulatory T-cell (iTreg) conversion and prevent the exhaustion of CAR-T cells. Meanwhile, TGFBR2 edited CAR-T cells had better in vivo tumor elimination efficacy, both in cell line derived xenograft (CDX) and patient derived xenograft (PDX) solid tumor models, whether administered locally or systemically. In addition, the TGFBR2 edited CAR-T cells could eliminate contralaterally re-inoculated xenografts in mice effectively with an increased proportion of central memory and effector memory subsets. In conclusion, we greatly improved the in vitro and in vivo function of CAR-T cells in TGFβ-rich tumor environments by knocking out endogenous TGFBR2, proposing a 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
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.134105.
Abstract
The HIV latent reservoir in resting memory CD4+ T cells prevents cure. Therapeutics to reactivate and eliminate this reservoir are in clinical trials in adults, but not in pediatric populations. We determined, ex vivo, the inducibility and size of the latent reservoir in perinatal compared with adult infections using the Tat/rev Induced Limiting Dilution Assay (TILDA), in which a single-round (12hr) 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. Despite similar rates of T cell activation with PMA/ionomycin, the latent reservoir in perinatal infection is slower to reactivate and of lower magnitude compared to adult infection, independent of proviral load. An enhanced TILDA with the addition of phytohemagglutin and for 18 hours augmented proviral expression in perinatal but not adult infection. Baseline HLA–DR+ CD4+ T cells was significantly lower in perinatal compared with adult infections, but not correlated with induced reservoir size. These data support differences in baseline immune activation and kinetics of latency reversal in perinatal compared with adult infections, with implications for latency reversal strategies towards 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 L. Nilles, R. Brad Jones, Vicki Tepper, Allison Agwu, Deborah Persaud
Citation Information: JCI Insight. 2020. https://doi.org/10.1172/jci.insight.131018.
Abstract
Inherited bone marrow failure syndromes (IBMFSs) 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 to other Xp(C>T)pX sites and enrichment for Cancer signature 1 (X indicates any nucleotide). Potential pre-leukemic targets in the GMP-like cells from FA/SDS patients included SYNE1, DST, HUWE1, LRP2, NOTCH2 and TP53. Serial analysis of GMPs from a 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 two FA/SDS patients with leukemia was similar to that of FA/SDS patients without transformation. The predicted founding clones in SDS-AML harbored mutations in several genes including TP53, while in FA-AML the mutated genes included ARID1B and SFPQ. We described 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 Claudia Heidemann, Brian Bursic, Sasan Zandi, Hongbing Li, Sagi Abelson, Robert J. Klaassen, Sharon Abish, Meera S Rayar, Vicky R. Breakey, Houtan Moshiri, Santhosh Dhanraj, Richard de Borja, Adam Shlien, John E. Dick, Yigal Dror
