Corinne L. Williams
Genome-wide association studies (GWAS) have provided a wealth of information on potential disease-associated genes in the human population. In particular, several loci have been associated with type 2 diabetes (T2D). However, due to the complexity of the disease, it has been a challenge to unravel the exact effects of specific loci on T2D pathogenesis. In this issue of the JCI, Keller and colleagues developed a systems genetic approach to identify insulin secretion–associated genes in nondiabetic mice followed by tissue-level and functional phenotyping. Several of the loci identified were syntenic with human T2D-related loci, indicating that this approach may be feasible for discerning genetic variation in nondiabetic individuals that may lead to the development of T2D.
Mark A. Herman, Jonathan E. Campbell, David A. D’Alessio
The stimulator of IFN genes (STING) signaling pathway is a critical link between innate and adaptive immunity and induces antitumor immune responses. STING is expressed in vasculatures, but its role in tumor angiogenesis has not been elucidated. Here, we investigated STING-induced tumor vascular remodeling and the potential of STING-based combination immunotherapy. Endothelial STING expression was correlated with enhanced T cell infiltration and prolonged survival in human colon and breast cancer. Intratumoral STING activation with STING agonists (cGAMP or RR-CDA) normalized tumor vasculatures in implanted and spontaneous cancers, but not in STING-deficient mice. These were mediated by upregulation of type I/II IFN genes and vascular stabilizing genes (e.g., Angpt1, Pdgfrb, and Col4a). STING in nonhematopoietic cells is as important as STING in hematopoietic cells for inducing a maximal therapeutic efficacy of exogenous STING agonists. Vascular normalizing effects of STING agonists were dependent on type I IFN signaling and CD8+ T cells. Notably, STING-based immunotherapy was maximally effective when combined with VEGFR2 blockade and/or immune-checkpoint blockade (αPD-1 or αCTLA-4), leading to complete regression of immunotherapy-resistant tumors. Our data show that intratumoral STING activation can normalize tumor vasculature and the tumor microenvironment, providing a rationale for combining STING-based immunotherapy and antiangiogenic therapy.
Hannah Yang, Won Suk Lee, So Jung Kong, Chang Gon Kim, Joo Hoon Kim, Sei Kyung Chang, Sewha Kim, Gwangil Kim, Hong Jae Chon, Chan Kim
Lysophosphatidic acid (LPA) is a potent lipid mediator with various biological functions mediated through six G protein–coupled receptors (GPCRs), LPA1–LPA6. Previous studies have demonstrated that LPA–Gα12/Gα13 signaling plays an important role in embryonic vascular development. However, the responsible LPA receptors and underlying mechanisms are poorly understood. Here, we show a critical role of LPA4 and LPA6 in developmental angiogenesis. In mice, Lpa4;Lpa6 double-knockout (DKO) embryos were lethal due to global vascular deficiencies, and endothelial cell–specific (EC-specific) Lpa4;Lpa6-DKO retinas had impaired sprouting angiogenesis. Mechanistically, LPA activated the transcriptional regulators YAP and TAZ through LPA4/LPA6–mediated Gα12/Gα13–Rho–ROCK signaling in ECs. YAP/TAZ knockdown increased endothelial expression of the Notch ligand delta-like ligand 4 (DLL4) that was mediated by β-catenin and Notch intracellular domain (NICD). Fibrin gel sprouting assay revealed that LPA4/LPA6, Gα12/Gα13, or YAP/TAZ knockdown consistently blocked EC sprouting, which was rescued by a Notch inhibitor. Notably, the inhibition of Notch signaling also ameliorated impaired retinal angiogenesis in EC-specific Lpa4;Lpa6-DKO mice. Overall, these results suggest that the Gα12/Gα13–coupled receptors LPA4 and LPA6 synergistically regulate endothelial Dll4 expression through YAP/TAZ activation. This could in part account for the mechanism of YAP/TAZ–mediated developmental angiogenesis. Our findings provide insight into the biology of GPCR-activated YAP/TAZ.
Daisuke Yasuda, Daiki Kobayashi, Noriyuki Akahoshi, Takayo Ohto-Nakanishi, Kazuaki Yoshioka, Yoh Takuwa, Seiya Mizuno, Satoru Takahashi, Satoshi Ishii
Despite progress in intensification of therapy, outcomes for patients with metastatic osteosarcoma (OS) have not improved in thirty years. We developed a system that enabled preclinical screening of compounds against metastatic OS cells in the context of the native lung microenvironment. Using this strategy to screen a library of epigenetically targeted compounds, we identified inhibitors of CDK12 to be most effective, reducing OS cell outgrowth in the lung by more than 90% at submicromolar doses. We found that knockout of CDK12 in an in vivo model of lung metastasis significantly decreased the ability of OS to colonize the lung. CDK12 inhibition led to defects in transcription elongation in a gene length– and expression-dependent manner. These effects were accompanied by defects in RNA processing and altered the expression of genes involved in transcription regulation and the DNA damage response. We further identified OS models that differ in their sensitivity to CDK12 inhibition in the lung and provided evidence that upregulated MYC levels may mediate these differences. Our studies provided a framework for rapid preclinical testing of compounds with antimetastatic activity and highlighted CDK12 as a potential therapeutic target in OS.
Ian Bayles, Malgorzata Krajewska, W. Dean Pontius, Alina Saiakhova, James J. Morrow, Cynthia Bartels, Jim Lu, Zachary J. Faber, Yuriy Fedorov, Ellen S. Hong, Jaret M. Karnuta, Brian Rubin, Drew J. Adams, Rani E. George, Peter C. Scacheri
Genetic susceptibility to type 2 diabetes is primarily due to β cell dysfunction. However, a genetic study to directly interrogate β cell function ex vivo has never been previously performed. We isolated 233,447 islets from 483 Diversity Outbred (DO) mice maintained on a Western-style diet, and measured insulin secretion in response to a variety of secretagogues. Insulin secretion from DO islets ranged greater than 1000-fold even though none of the mice were diabetic. The insulin secretory response to each secretagogue had a unique genetic architecture; some of the loci were specific for one condition, whereas others overlapped. Human loci that are syntenic to many of the insulin secretion quantitative trait loci (QTL) from mice are associated with diabetes-related SNPs in human genome-wide association studies. We report on 3 genes, Ptpn18, Hunk, and Zfp148, where the phenotype predictions from the genetic screen were fulfilled in our studies of transgenic mouse models. These 3 genes encode a nonreceptor type protein tyrosine phosphatase, a serine/threonine protein kinase, and a Krϋppel-type zinc-finger transcription factor, respectively. Our results demonstrate that genetic variation in insulin secretion that can lead to type 2 diabetes is discoverable in nondiabetic individuals.
Mark P. Keller, Mary E. Rabaglia, Kathryn L. Schueler, Donnie S. Stapleton, Daniel M. Gatti, Matthew Vincent, Kelly A. Mitok, Ziyue Wang, Takanao Ishimura, Shane P. Simonett, Christopher H. Emfinger, Rahul Das, Tim Beck, Christina Kendziorski, Karl W. Broman, Brian S. Yandell, Gary A. Churchill, Alan D. Attie
Obesity originates from an imbalance between caloric intake and energy expenditure that promotes adipose tissue expansion, which is necessary to buffer nutrient excess. Patients with higher visceral fat mass are at a higher risk of developing severe complications such as type 2 diabetes and cardiovascular and liver diseases. However, increased fat mass does not fully explain obesity’s propensity to promote metabolic diseases. With chronic obesity, adipose tissue undergoes major remodeling, which can ultimately result in unresolved chronic inflammation leading to fibrosis accumulation. These features drive local tissue damage and initiate and/or maintain multiorgan dysfunction. Here, we review the current understanding of adipose tissue remodeling with a focus on obesity-induced adipose tissue fibrosis and its relevance to clinical manifestations.
Geneviève Marcelin, Ana Letícia M. Silveira, Laís Bhering Martins, Adaliene V.M. Ferreira, Karine Clément
3-M primordial dwarfism is an inherited disease characterized by severe pre- and postnatal growth retardation and by mutually exclusive mutations in 3 genes, CUL7, OBSL1, and CCDC8. The mechanism underlying 3-M dwarfism is not clear. We showed here that CCDC8, derived from a retrotransposon Gag protein in placental mammals, exclusively localized on the plasma membrane and was phosphorylated by CK2 and GSK3. Phosphorylation of CCDC8 resulted in its binding first with OBSL1, and then CUL7, leading to the membrane assembly of the 3-M E3 ubiquitin ligase complex. We identified LL5β, a plasma membrane protein that regulates cell migration, as a substrate of 3-M ligase. Wnt inhibition of CCDC8 phosphorylation or patient-derived mutations in 3-M genes disrupted membrane localization of the 3-M complex and accumulated LL5β. Deletion of Ccdc8 in mice impaired trophoblast migration and placental development, resulting in intrauterine growth restriction and perinatal lethality. These results identified a mechanism regulating cell migration and placental development that underlies the development of 3-M dwarfism.
Pu Wang, Feng Yan, Zhijun Li, Yanbao Yu, Scott E. Parnell, Yue Xiong
Reactive astrocytes are associated with every form of neurological injury. Despite their ubiquity, the molecular mechanisms controlling their production and diverse functions remain poorly defined. Because many features of astrocyte development are recapitulated in reactive astrocytes, we investigated the role of nuclear factor I-A (NFIA), a key transcriptional regulator of astrocyte development whose contributions to reactive astrocytes remain undefined. Here, we show that NFIA is highly expressed in reactive astrocytes in human neurological injury and identify unique roles across distinct injury states and regions of the CNS. In the spinal cord, after white matter injury (WMI), NFIA-deficient astrocytes exhibit defects in blood-brain barrier remodeling, which are correlated with the suppression of timely remyelination. In the cortex, after ischemic stroke, NFIA is required for the production of reactive astrocytes from the subventricular zone (SVZ). Mechanistically, NFIA directly regulates the expression of thrombospondin 4 (Thbs4) in the SVZ, revealing a key transcriptional node regulating reactive astrogenesis. Together, these studies uncover critical roles for NFIA in reactive astrocytes and illustrate how region- and injury-specific factors dictate the spectrum of reactive astrocyte responses.
Dylan Laug, Teng-Wei Huang, Navish A. Bosquez Huerta, Anna Yu-Szu Huang, Debosmita Sardar, Joshua Ortiz-Guzman, Jeffrey C. Carlson, Benjamin R. Arenkiel, Chay T. Kuo, Carrie A. Mohila, Stacey M. Glasgow, Hyun Kyoung Lee, Benjamin Deneen
Inflammatory destruction of iron-rich myelin is characteristic of multiple sclerosis (MS). Although iron is needed for oligodendrocytes to produce myelin during development, its deposition has also been linked to neurodegeneration and inflammation, including in MS. We report perivascular iron deposition in multiple sclerosis lesions that was mirrored in 72 lesions from 13 marmosets with experimental autoimmune encephalomyelitis. Iron accumulated mainly inside microglia/macrophages from 6 weeks after demyelination. Consistently, expression of transferrin receptor, the brain’s main iron-influx protein, increased as lesions aged. Iron was uncorrelated with inflammation and postdated initial demyelination, suggesting that iron is not directly pathogenic. Iron homeostasis was at least partially restored in remyelinated, but not persistently demyelinated, lesions. Taken together, our results suggest that iron accumulation in the weeks after inflammatory demyelination may contribute to lesion repair rather than inflammatory demyelination per se.
Nathanael J. Lee, Seung-Kwon Ha, Pascal Sati, Martina Absinta, Govind Nair, Nicholas J. Luciano, Emily C. Leibovitch, Cecil C. Yen, Tracey A. Rouault, Afonso C. Silva, Steven Jacobson, Daniel S. Reich
Brain somatic mutations confer genomic diversity in the human brain and cause neurodevelopmental disorders. Recently, brain somatic activating mutations in MTOR have been identified as a major etiology of intractable epilepsy in patients with cortical malformations. However, the molecular genetic mechanism of how brain somatic mutations in MTOR cause intractable epilepsy has remained elusive. In this study, translational profiling of intractable epilepsy mouse models with brain somatic mutations and genome-edited cells revealed a novel translational dysregulation mechanism and mTOR activation–sensitive targets mediated by human MTOR mutations that lead to intractable epilepsy with cortical malformation. These mTOR targets were found to be regulated by novel mTOR-responsive 5′-UTR motifs, distinct from known mTOR inhibition–sensitive targets regulated by 5′ terminal oligopyrimidine motifs. Novel mTOR target genes were validated in patient brain tissues, and the mTOR downstream effector eIF4E was identified as a new therapeutic target in intractable epilepsy via pharmacological or genetic inhibition. We show that metformin, an FDA-approved eIF4E inhibitor, suppresses intractable epilepsy. Altogether, the present study describes translational dysregulation resulting from brain somatic mutations in MTOR, as well as the pathogenesis and potential therapeutic targets of intractable epilepsy.
Jang Keun Kim, Jun Cho, Se Hoon Kim, Hoon-Chul Kang, Dong-Seok Kim, V. Narry Kim, Jeong Ho Lee
Adipose tissue plays important roles in regulating whole-body energy metabolism through its storage function in white adipocytes and its dissipating function in brown and beige adipocytes. Adipose tissue also produces a variety of secreted factors called adipocytokines, including leptin and adiponectin. Furthermore, recent studies have suggested the important roles of extracellular vesicles of endosomal origin termed exosomes, which are secreted from adipocytes and other cells in adipose tissue and influence whole-body glucose and lipid metabolism. Adiponectin is known to be a pleiotropic organ-protective protein that is exclusively produced by adipocytes and decreased in obesity. Adiponectin accumulates in tissues such as heart, muscle, and vascular endothelium through binding with T-cadherin, a glycosylphosphatidylinositol-anchored (GPI-anchored) cadherin. Recently, adiponectin was found to enhance exosome biogenesis and secretion, leading to a decrease in cellular ceramides, excess of which is known to cause insulin resistance and cardiovascular disease phenotypes. These findings support the hypothesis that adipose tissue metabolism systemically regulates exosome production and whole-body metabolism through exosomes. This review focuses on intra-adipose and interorgan communication by exosomes, adiponectin-stimulated exosome production, and their dysregulation in metabolic diseases.
Shunbun Kita, Norikazu Maeda, Iichiro Shimomura
BACKGROUND Checkpoint inhibitor pneumonitis (CIP) is a highly morbid complication of immune checkpoint immunotherapy (ICI), one which precludes the continuation of ICI. Yet, the mechanistic underpinnings of CIP are unknown.METHODS To better understand the mechanism of lung injury in CIP, we prospectively collected bronchoalveolar lavage (BAL) samples in ICI-treated patients with (n = 12) and without CIP (n = 6), prior to initiating first-line therapy for CIP (high-dose corticosteroids). We analyzed BAL immune cell populations using a combination of traditional multicolor flow cytometry gating, unsupervised clustering analysis, and BAL supernatant cytokine measurements.RESULTS We found increased BAL lymphocytosis, predominantly CD4+ T cells, in patients with CIP. Specifically, we observed increased numbers of BAL central memory T cells, evidence of type I polarization, and decreased expression of cytotoxic T lymphocyte–associated protein 4 and programmed cell death protein 1 in BAL Tregs, suggesting both activation of proinflammatory subsets and an attenuated suppressive phenotype. CIP BAL myeloid immune populations displayed enhanced expression of IL-1β and decreased expression of counterregulatory interleukin-1 receptor antagonist. We observed increased levels of T-cell chemoattractants in the BAL supernatant, consistent with our proinflammatory, lymphocytic cellular landscape.CONCLUSION We observe several immune cell subpopulations that are dysregulated in CIP, which may represent possible targets that could lead to therapeutics for this morbid immune-related adverse event.FUNDING NIH, Department of Defense, and the Bloomberg~Kimmel Institute for Cancer Immunotherapy.
Karthik Suresh, Jarushka Naidoo, Qiong Zhong, Ye Xiong, Jennifer Mammen, Marcia Villegas de Flores, Laura Cappelli, Aanika Balaji, Tsvi Palmer, Patrick M. Forde, Valsamo Anagnostou, David S. Ettinger, Kristen A. Marrone, Ronan J. Kelly, Christine L. Hann, Benjamin Levy, Josephine L. Feliciano, Cheng-Ting Lin, David Feller-Kopman, Andrew D. Lerner, Hans Lee, Majid Shafiq, Lonny Yarmus, Evan J. Lipson, Mark Soloski, Julie R. Brahmer, Sonye K. Danoff, Franco D’Alessio
Prostate cancer (PC) initially depends on androgen receptor (AR) signaling for survival and growth. Therapeutics designed to suppress AR activity serve as the primary intervention for advanced disease. However, supraphysiological androgen (SPA) concentrations can produce paradoxical responses leading to PC growth inhibition. We sought to discern the mechanisms by which SPA inhibits PC and to determine if molecular context associates with antitumor activity. SPA produced an AR-mediated, dose-dependent induction of DNA double-strand breaks, G0/G1 cell-cycle arrest, and cellular senescence. SPA repressed genes involved in DNA repair and delayed the restoration of damaged DNA, which was augmented by poly (ADP-ribose) polymerase 1 inhibition. SPA-induced double-strand breaks were accentuated in BRCA2-deficient patients with PC, and combining SPA with poly (ADP-ribose) polymerase or DNA-dependent protein kinase inhibition further repressed growth. Next-generation sequencing was performed on biospecimens from patients with PC receiving SPA as part of ongoing phase II clinical trials. Patients with mutations in genes mediating homology-directed DNA repair were more likely to exhibit clinical responses to SPA. These results provide a mechanistic rationale for directing SPA therapy to patients with PC who have AR amplification or DNA repair deficiency and for combining SPA therapy with poly (ADP-ribose) polymerase inhibition.
Payel Chatterjee, Michael T. Schweizer, Jared M. Lucas, Ilsa Coleman, Michael D. Nyquist, Sander B. Frank, Robin Tharakan, Elahe Mostaghel, Jun Luo, Colin C. Pritchard, Hung-Ming Lam, Eva Corey, Emmanuel S. Antonarakis, Samuel R. Denmeade, Peter S. Nelson
Electronic nicotine delivery systems (ENDS) are rapidly increasing in popularity due to the perception that they may represent a safe alternative to conventional cigarettes. However, a growing body of evidence indicates that ENDS exposure can disrupt maintenance of pulmonary immune homeostasis and antimicrobial immunity. In this issue of the JCI, Madison et al. demonstrate that in mice, chronic ENDS exposure induces profound alterations in lipid homeostasis. ENDS-exposed mice showed irregularities in the surfactant-secreting lamellar bodies within type 2 alveolar cells and increased intracellular phospholipid accumulation within alveolar macrophages. Moreover, ENDS-exposed mice displayed greater inflammation and tissue damage in response to influenza A, which may be due to downregulated expression of a viral pattern–recognition receptor in alveolar macrophages. Collectively, the results of this study identify previously unrecognized adverse effects of ENDS exposure on pulmonary lipid metabolism, although the implication of these effects on long-term respiratory health requires future exploration.
Aran Singanayagam, Robert J. Snelgrove
Electronic nicotine delivery systems (ENDS) or e-cigarettes have emerged as a popular recreational tool among adolescents and adults. Although the use of ENDS is often promoted as a safer alternative to conventional cigarettes, few comprehensive studies have assessed the long-term effects of vaporized nicotine and its associated solvents, propylene glycol (PG) and vegetable glycerin (VG). Here, we show that compared with smoke exposure, mice receiving ENDS vapor for 4 months failed to develop pulmonary inflammation or emphysema. However, ENDS exposure, independent of nicotine, altered lung lipid homeostasis in alveolar macrophages and epithelial cells. Comprehensive lipidomic and structural analyses of the lungs revealed aberrant phospholipids in alveolar macrophages and increased surfactant-associated phospholipids in the airway. In addition to ENDS-induced lipid deposition, chronic ENDS vapor exposure downregulated innate immunity against viral pathogens in resident macrophages. Moreover, independent of nicotine, ENDS-exposed mice infected with influenza demonstrated enhanced lung inflammation and tissue damage. Together, our findings reveal that chronic e-cigarette vapor aberrantly alters the physiology of lung epithelial cells and resident immune cells and promotes poor response to infectious challenge. Notably, alterations in lipid homeostasis and immune impairment are independent of nicotine, thereby warranting more extensive investigations of the vehicle solvents used in e-cigarettes.
Matthew C. Madison, Cameron T. Landers, Bon-Hee Gu, Cheng-Yen Chang, Hui-Ying Tung, Ran You, Monica J. Hong, Nima Baghaei, Li-Zhen Song, Paul Porter, Nagireddy Putluri, Ramiro Salas, Brian E. Gilbert, Ilya Levental, Matthew J. Campen, David B. Corry, Farrah Kheradmand
BACKGROUND Adenoid cystic carcinoma (ACC) is a rare malignancy arising in salivary glands and other sites, characterized by high rates of relapse and distant spread. Recurrent/metastatic (R/M) ACCs are generally incurable, due to a lack of active systemic therapies. To improve outcomes, deeper understanding of genetic alterations and vulnerabilities in R/M tumors is needed.METHODS An integrated genomic analysis of 1,045 ACCs (177 primary, 868 R/M) was performed to identify alterations associated with advanced and metastatic tumors. Intratumoral genetic heterogeneity, germline mutations, and therapeutic actionability were assessed.RESULTS Compared with primary tumors, R/M tumors were enriched for alterations in key Notch (NOTCH1, 26.3% vs. 8.5%; NOTCH2, 4.6% vs. 2.3%; NOTCH3, 5.7% vs. 2.3%; NOTCH4, 3.6% vs. 0.6%) and chromatin-remodeling (KDM6A, 15.2% vs. 3.4%; KMT2C/MLL3, 14.3% vs. 4.0%; ARID1B, 14.1% vs. 4.0%) genes. TERT promoter mutations (13.1% of R/M cases) were mutually exclusive with both NOTCH1 mutations (q = 3.3 × 10–4) and MYB/MYBL1 fusions (q = 5.6 × 10–3), suggesting discrete, alternative mechanisms of tumorigenesis. This network of alterations defined 4 distinct ACC subgroups: MYB+NOTCH1+, MYB+/other, MYBWTNOTCH1+, and MYBWTTERT+. Despite low mutational load, we identified numerous samples with marked intratumoral genetic heterogeneity, including branching evolution across multiregion sequencing.CONCLUSION These observations collectively redefine the molecular underpinnings of ACC progression and identify further targets for precision therapies.FUNDING Adenoid Cystic Carcinoma Research Foundation, Pershing Square Sohn Cancer Research grant, the PaineWebber Chair, Stand Up 2 Cancer, NIH R01 CA205426, the STARR Cancer Consortium, NCI R35 CA232097, the Frederick Adler Chair, Cycle for Survival, the Jayme Flowers Fund, The Sebastian Nativo Fund, NIH K08 DE024774 and R01 DE027738, and MSKCC through NIH/NCI Cancer Center Support Grant (P30 CA008748).
Allen S. Ho, Angelica Ochoa, Gowtham Jayakumaran, Ahmet Zehir, Cristina Valero Mayor, Justin Tepe, Vladimir Makarov, Martin G. Dalin, Jie He, Mark Bailey, Meagan Montesion, Jeffrey S. Ross, Vincent A. Miller, Lindsay Chan, Ian Ganly, Snjezana Dogan, Nora Katabi, Petros Tsipouras, Patrick Ha, Nishant Agrawal, David B. Solit, P. Andrew Futreal, Adel K. El Naggar, Jorge S. Reis-Filho, Britta Weigelt, Alan L. Ho, Nikolaus Schultz, Timothy A. Chan, Luc G.T. Morris
Inflammation plays a critical role in the development of severe neonatal morbidities. Myeloid-derived suppressor cells (MDSCs) were recently implicated in the regulation of immune responses in newborns. Here, we report that the presence of MDSCs and their functional activity in infants are closely associated with the maturity of newborns and the presence of lactoferrin (LF) in serum. Low amounts of MDSCs at birth predicted the development of severe pathology in preterm infants — necrotizing enterocolitis (NEC). In vitro treatment of newborn neutrophils and monocytes with LF converted these cells to MDSCs via the LRP2 receptor and activation of the NF-κB transcription factor. Decrease in the expression of LRP2 was responsible for the loss of sensitivity of adult myeloid cells to LF. LF-induced MDSCs (LF-MDSCs) were effective in the treatment of newborn mice with NEC, acting by blocking inflammation, resulting in increased survival. LF-MDSCs were more effective than treatment with LF protein alone. In addition to affecting NEC, LF-MDSCs demonstrated potent ability to control ovalbumin-induced (OVA-induced) lung inflammation, dextran sulfate sodium–induced (DSS-induced) colitis, and concanavalin A–induced (ConA-induced) hepatitis. These results suggest that cell therapy with LF-MDSCs may provide potent therapeutic benefits in infants with various pathological conditions associated with dysregulated inflammation.
Yufeng Liu, Michela Perego, Qiang Xiao, Yumei He, Shuyu Fu, Juan He, Wangkai Liu, Xing Li, Yanlai Tang, Xiaoyu Li, Weiming Yuan, Wei Zhou, Fan Wu, Chunhong Jia, Qiliang Cui, George S. Worthen, Erik A. Jensen, Dmitry I. Gabrilovich, Jie Zhou
Recent work demonstrated a role for myeloid-derived suppressor cells (MDSCs) in the antimicrobial response in newborns, but the signals guiding their differentiation remained unknown. In this issue of the JCI, Liu et al. demonstrate that lactoferrin (LF) converts newborn neutrophils and monocytes to MDSCs via the low-density lipoprotein receptor–related protein-2 (LRP2) receptor and NF-κB activation. Due to their strong antimicrobial activity, adoptive transfer of MDSCs generated by in vitro culture with LF prolonged the survival of newborn mice with necrotizing enterocolitis, a severe pathology in preterm infants. These findings indicate a surprising protective role of MDSCs in newborns and demonstrate the potential of MDSC therapy for the treatment of infants with diseases associated with deregulated inflammation.
Rebekka Weber, Viktor Umansky