Latest issue: July 12, 2018

In the issue

Abstract

The contribution of the kidney-draining lymph node (KLN) to the pathogenesis of ischemia-reperfusion injury (IRI) of the kidney and its subsequent recovery has not been explored in depth. In addition, the mechanism by which repetitive IRI contributes to renal fibrosis remains poorly understood. Herein, we have found that IRI of the kidney is associated with expansion of high endothelial venules (HEVs) and activation of fibroblastic reticular cells (FRCs) in the KLN, as demonstrated by significant expansion in the extracellular matrix. The lymphotoxin α signaling pathway mediates activation of FRCs, and chronic treatment with lymphotoxin β receptor–immunoglobulin fusion protein (LTβr-Ig) resulted in marked alteration of the KLN as well as augmentation of renal fibrosis. Depletion of FRCs reduced T cell activation in the KLN and ameliorated renal injury in acute IRI. Repetitive renal IRI was associated with senescence of FRCs, fibrosis of the KLN, and renal scarring, which were ameliorated by FRC administration. Therefore, our study emphasizes the critical role of FRCs in both the initiation and repair phases of injury following IRI of the kidney.

Authors

Omar H. Maarouf, Mayuko Uehara, Vivek Kasinath, Zhabiz Solhjou, Naima Banouni, Baharak Bahmani, Liwei Jiang, Osman A. Yilmam, Indira Guleria, Scott B. Lovitch, Jane L. Grogan, Paolo Fiorina, Peter T. Sage, Jonathan S. Bromberg, Martina M. McGrath, Reza Abdi

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Abstract

Numerous studies of relatively few patients have linked T cell receptor (TCR) genes to psoriasis but have yielded dramatically conflicting results. To resolve these discrepancies, we have chosen to mine RNA-Seq datasets for patterns of TCR gene segment usage in psoriasis. A meta-analysis of 3 existing and 1 unpublished datasets revealed a statistically significant link between the relative expression of TRAJ23 and psoriasis and the psoriasis-associated cytokine IL-17A. TRGV5, a TCR-γ segment, was also associated with psoriasis but correlated instead with IL-36A, other IL-36 family members, and IL-17C (not IL-17A). In contrast, TRAJ39 was strongly associated with healthy skin. T cell diversity measurements and analysis of CDR3 sequences were also conducted, revealing no psoriasis-associated public CDR3 sequences. Finally, in comparison with the expression of TCR-αβ genes, the expression of TCR-γδ genes was relatively low but mildly elevated in psoriatic skin. These results have implications for the development of targeted therapies for psoriasis and other autoimmune diseases. Also, the techniques employed in this study have applications in other fields, such as cancer immunology and infectious disease.

Authors

Alexander A. Merleev, Alina I. Marusina, Chelsea Ma, James T. Elder, Lam C. Tsoi, Siba P. Raychauduri, Stephan Weidinger, Elizabeth A. Wang, Iannis E. Adamopoulos, Guillaume Luxardi, Johann E. Gudjonsson, Michiko Shimoda, Emanual Maverakis

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Abstract

Preeclampsia and fetal growth restriction (FGR) are major causes of the more than 5 million perinatal and infant deaths occurring globally each year, and both are associated with placental dysfunction. The risk of perinatal and infant death is greater in males, but the mechanisms are unclear. We studied data and biological samples from the Pregnancy Outcome Prediction (POP) study, a prospective cohort study that followed 4,212 women having first pregnancies from their dating ultrasound scan through delivery. We tested the hypothesis that fetal sex would be associated with altered placental function using multiomic and targeted analyses. We found that spermine synthase (SMS) escapes X-chromosome inactivation (XCI) in the placenta and is expressed at lower levels in male primary trophoblast cells, and male cells were more sensitive to polyamine depletion. The spermine metabolite N1,N12-diacetylspermine (DiAcSpm) was higher in the female placenta and in the serum of women pregnant with a female fetus. Higher maternal serum levels of DiAcSpm increased the risk of preeclampsia but decreased the risk of FGR. To our knowledge, DiAcSpm is the first maternal biomarker to demonstrate opposite associations with preeclampsia and FGR, and this is the first evidence to implicate polyamine metabolism in sex-related differences in placentally related complications of human pregnancy.

Authors

Sungsam Gong, Ulla Sovio, Irving L.M.H. Aye, Francesca Gaccioli, Justyna Dopierala, Michelle D. Johnson, Angela M. Wood, Emma Cook, Benjamin J. Jenkins, Albert Koulman, Robert A. Casero Jr., Miguel Constância, D. Stephen Charnock-Jones, Gordon C.S. Smith

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Abstract

BACKGROUND. Noroviruses are the leading cause of epidemic acute gastroenteritis and foodborne diarrheal disease in humans. However, there are no approved vaccines for noroviruses. Potential correlates of protection identified through human challenge studies include mucosal IgA, memory B cells, and serum-blocking antibody titers (BT50). METHODS. We conducted a single-site, randomized, double-blind, placebo-controlled clinical trial of an oral norovirus vaccine to determine safety and immunogenicity. This tablet vaccine is comprised of a nonreplicating adenovirus-based vector expressing the VP1 gene from the GI.1 norovirus strain and a double-stranded RNA adjuvant. Sixty-six adult subjects meeting inclusion/exclusion criteria were randomized 2:1 to receive a single vaccine dose or placebo, respectively. Immunogenicity was primarily assessed by serum BT50. Additional outcomes included serum ELISA titers, fecal and saliva antibody titers, memory and antibody-secreting cell (ASC) frequency, and B cell phenotyping. RESULTS. The vaccine was well-tolerated, with no dose-limiting toxicities. Adverse events were mild or moderate. The primary immunological endpoint (increase in BT50 titers) was met in the high-dose group (P = 0.0003), with 78% showing a ≥2-fold rise in titers after a single immunization. Vaccine recipients also developed mucosally primed VP1-specific circulating ASCs, IgA+ memory B cells expressing gut-homing receptor (α4β7), and fecal IgA, indicating substantial and local responses potentially relevant to prevent norovirus infection. CONCLUSION. This oral norovirus vaccine was well-tolerated and generated substantial immune responses, including systemic and mucosal antibodies as well as memory IgA/IgG. These results are a major step forward for the development of a safe and immunogenic oral norovirus vaccine. TRIAL REGISTRATION. ClinicalTrials.gov NCT02868073. FUNDING. Vaxart.

Authors

Leesun Kim, David Liebowitz, Karen Lin, Kassandra Kasparek, Marcela F. Pasetti, Shaily J. Garg, Keith Gottlieb, George Trager, Sean N. Tucker

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Abstract

Chikungunya virus (CHIKV) causes acute and chronic rheumatologic disease. Pathogenic CHIKV strains persist in joints of immunocompetent mice, while the attenuated CHIKV strain 181/25 is cleared by adaptive immunity. We analyzed the draining lymph node (dLN) to define events in lymphoid tissue that may contribute to CHIKV persistence or clearance. Acute 181/25 infection resulted in dLN enlargement and germinal center (GC) formation, while the dLN of mice infected with pathogenic CHIKV became highly disorganized and depleted of lymphocytes. Using CHIKV strains encoding ovalbumin-specific TCR epitopes, we found that lymphocyte depletion was not due to impaired lymphocyte proliferation. Instead, the accumulation of naive lymphocytes transferred from the vasculature to the dLN was reduced, which was associated with fewer high endothelial venule cells and decreased CCL21 production. Following NP-OVA immunization, NP-specific GC B cells in the dLN were decreased during pathogenic, but not attenuated, CHIKV infection. Our data suggest that pathogenic, persistent strains of CHIKV disable the development of adaptive immune responses within the dLN.

Authors

Mary K. McCarthy, Bennett J. Davenport, Glennys V. Reynoso, Erin D. Lucas, Nicholas A. May, Susan A. Elmore, Beth A. Tamburini, Heather D. Hickman, Thomas E. Morrison

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Abstract

Nonneuronal cell types in the CNS are increasingly implicated as critical players in brain health and disease. While gene expression profiling of bulk brain tissue is routinely used to examine alterations in the brain under various conditions, it does not capture changes that occur within single cell types or allow interrogation of crosstalk among cell types. To this end, we have developed a concurrent brain cell type acquisition (CoBrA) methodology, enabling the isolation and profiling of microglia, astrocytes, endothelia, and oligodendrocytes from a single adult mouse forebrain. By identifying and validating anti-ACSA-2 and anti-CD49a antibodies as cell surface markers for astrocytes and vascular endothelial cells, respectively, and using established antibodies to isolate microglia and oligodendrocytes, we document that these 4 major cell types are isolated with high purity and RNA quality. We validated our procedure by performing acute peripheral LPS challenge, while highlighting the underappreciated changes occurring in astrocytes and vascular endothelia in addition to microglia. Furthermore, we assessed cell type–specific gene expression changes in response to amyloid pathology in a mouse model of Alzheimer’s disease. Our CoBrA methodology can be readily implemented to interrogate multiple CNS cell types in any mouse model at any age.

Authors

Dan B. Swartzlander, Nicholas E. Propson, Ethan R. Roy, Takashi Saito, Takaomi Saido, Baiping Wang, Hui Zheng

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Abstract

Cytokines play an important role in dysregulated immune responses to infection, pancreatitis, ischemia/reperfusion injury, burns, hemorrhage, cardiopulmonary bypass, trauma, and many other diseases. Moreover, the imbalance between inflammatory and antiinflammatory cytokines can have deleterious effects. Here, we demonstrated highly selective blood-filtering devices — antibody-modified conduits (AMCs) — that selectively eliminate multiple specific deleterious cytokines in vitro. AMCs functionalized with antibodies against human vascular endothelial growth factor A or tumor necrosis factor α (TNF-α) selectively eliminated the target cytokines from human blood in vitro and maintained them in reduced states even in the face of ongoing infusion at supraphysiologic rates. We characterized the variables that determine AMC performance, using anti–human TNF-α AMCs to eliminate recombinant human TNF-α. Finally, we demonstrated selective cytokine elimination in vivo by filtering interleukin 1 β from rats with lipopolysaccharide-induced hypercytokinemia.

Authors

J. Brian McAlvin, Ryan G. Wylie, Krithika Ramchander, Minh T. Nguyen, Charles K. Lok, Morgan Moroi, Andre Shomorony, Nikolay V. Vasilyev, Patrick Armstrong, Jason Yang, Alexander M. Lieber, Obiajulu S. Okonkwo, Rohit Karnik, Daniel S. Kohane

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Abstract

BACKGROUND. The prevalence of chronic kidney disease (CKD) is increasing worldwide. The identification of factors contributing to its progression is important for designing preventive measures. Previous studies have suggested that chronically high vasopressin is deleterious to renal function. Here, we evaluated the association of plasma copeptin, a surrogate of vasopressin, with the incidence of CKD in the general population. METHODS. We studied 3 European cohorts: DESIR (n = 5,047; France), MDCS-CC (n = 3,643; Sweden), and PREVEND (n = 7,684; the Netherlands). Median follow-up was 8.5, 16.5, and 11.3 years, respectively. Pooled data were analyzed at an individual level for 4 endpoints during follow-up: incidence of stage 3 CKD (estimated glomerular filtration rate [eGFR] < 60 ml/min/1.73 m2); the KDIGO criterion “certain drop in eGFR”; rapid kidney function decline (eGFR slope steeper than –3 ml/min/1.73 m2/yr); and incidence of microalbuminuria. RESULTS. The upper tertile of plasma copeptin was significantly and independently associated with a 49% higher risk for stage 3 CKD (P < 0.0001); a 64% higher risk for kidney function decline, as defined by the KDIGO criterion (P < 0.0001); a 79% higher risk for rapid kidney function decline (P < 0.0001); and a 24% higher risk for microalbuminuria (P = 0.008). CONCLUSIONS. High copeptin levels are associated with the development and the progression of CKD in the general population. Intervention studies are needed to assess the potential beneficial effect on kidney health in the general population of reducing vasopressin secretion or action. FUNDING. INSERM and Danone Research Centre for Specialized Nutrition.

Authors

Ray El Boustany, Irina Tasevska, Esther Meijer, Lyanne M. Kieneker, Sofia Enhörning, Guillaume Lefèvre, Kamel Mohammedi, Michel Marre, Frédéric Fumeron, Beverley Balkau, Nadine Bouby, Lise Bankir, Stephan J.L. Bakker, Ronan Roussel, Olle Melander, Ron T. Gansevoort, Gilberto Velho

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Abstract

To what extent does the subarachnoid cerebrospinal fluid (CSF) compartment communicate directly with the extravascular compartment of human brain tissue? Interconnection between the subarachnoid CSF compartment and brain perivascular spaces is reported in some animal studies, but with controversy, and in vivo CSF tracer studies in humans are lacking. In the present work, we examined the distribution of a CSF tracer in the human brain by MRI over a prolonged time span. For this, we included a reference cohort, representing close to healthy individuals, and a cohort of patients with dementia and anticipated compromise of CSF circulation (idiopathic normal pressure hydrocephalus). The MRI contrast agent gadobutrol, which is confined to the extravascular brain compartment by the intact blood-brain barrier, was used as a CSF tracer. Standardized T1-weighted MRI scans were performed before and after intrathecal gadobutrol at defined time points, including at 24 hours, 48 hours, and 4 weeks. All MRI scans were aligned and brain regions were segmented using FreeSurfer, and changes in normalized T1 signals over time were quantified as percentage change from baseline. The study provides in vivo evidence of access to all human brain subregions of a substance administered intrathecally. Clearance of the tracer substance was delayed in the dementia cohort. These observations translate previous findings in animal studies into humans and open new prospects concerning intrathecal treatment regimens, extravascular contrast-enhanced MRI, and assessment of brain clearance function.

Authors

Geir Ringstad, Lars M. Valnes, Anders M. Dale, Are H. Pripp, Svein-Are S. Vatnehol, Kyrre E. Emblem, Kent-Andre Mardal, Per K. Eide

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Abstract

Mice are extremely important as the premier model organism in human biomedical and mammalian genetic research. The genomes of several tens of mouse inbred strains have been sequenced. They have been compared to the genome of C57BL/6J, considered by convention as the reference genome. Based on a comparison of this reference genome with 36 other sequenced mouse strains, we generated an overview of all protein-coding genes that are deviant in this reference genome, compared with consensus protein-coding mouse gene sequences. We provide PROVEAN scores, reflecting the likelihood that these C57BL/6J proteins have lost function. We thus identified numerous abnormal proteins, and biological pathways, specifically present in C57BL/6J, suggesting the important caveats of this reference mouse strain, and linking candidate genes to some of the best-known phenotypes of this strain.

Authors

Steven Timmermans, Claude Libert

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Abstract

BACKGROUND. Immune checkpoint inhibitors provide significant clinical benefit to a subset of patients, but novel prognostic markers are needed to predict which patients will respond. This study was initiated to determine if features of patient T cell repertoires could provide insights into the mechanisms of immunotherapy, while also predicting outcomes. METHODS. We examined T cell receptor (TCR) repertoires in peripheral blood of 25 metastatic pancreatic cancer patients treated with ipilimumab with or without GVAX (a pancreatic cancer vaccine), as well as peripheral blood and tumor biopsies from 32 patients treated with GVAX and mesothelin-expressing Listeria monocytogenes with or without nivolumab. Statistics from these repertoires were then tested for their association with clinical response and treatment group. RESULTS. We demonstrate that, first, the majority of patients receiving these treatments experience a net diversification of their peripheral TCR repertoires. Second, patients receiving ipilimumab experienced larger changes in their repertoires, especially in combination with GVAX. Finally, both a low baseline clonality and a high number of expanded clones following treatment were associated with significantly longer survival in patients who received ipilimumab but not in patients receiving nivolumab. CONCLUSIONS. We show that these therapies have measurably different effects on the peripheral repertoire, consistent with their mechanisms of action, and demonstrate the potential for TCR repertoire profiling to serve as a biomarker of clinical response in pancreatic cancer patients receiving immunotherapy. In addition, our results suggest testing sequential administration of anti–CTLA-4 and anti–PD-1 antibodies to achieve optimal therapeutic benefit. TRIAL REGISTRATION. Samples used in this study were collected from the NCT00836407 and NCT02243371 clinical trials. FUNDING. Research supported by a Stand Up To Cancer Lustgarten Foundation Pancreatic Cancer Convergence Dream Team Translational Research grant (SU2C-AACR-DT14-14). Stand Up To Cancer is a program of the Entertainment Industry Foundation administered by the American Association for Cancer Research (AACR). Additional clinical trial funding was provided by AACR-Pancreatic Cancer Action Network Research Acceleration Network grant (14-90-25-LE), NCI SPORE in GI Cancer (CA062924), Quick-Trials for Novel Cancer Therapies: Exploratory Grants (R21CA126058-01A2), and the US Food and Drug Administration (R01FD004819). Research collaboration and financial support were provided by Adaptive Biotechnologies.

Authors

Alexander C. Hopkins, Mark Yarchoan, Jennifer N. Durham, Erik C. Yusko, Julie A. Rytlewski, Harlan S. Robins, Daniel A. Laheru, Dung T. Le, Eric R. Lutz, Elizabeth M. Jaffee

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Abstract

The maintenance of effective immunity over time is dependent on the capacity of hematopoietic stem cells (HSCs) to sustain the pool of immunocompetent mature cells. Decline of immune competence with old age may stem from HSC defects, including reduced self-renewal potential and impaired lymphopoiesis, as suggested in murine models. To obtain further insights into aging-related alteration of hematopoiesis, we performed a comprehensive study of blood hematopoietic progenitor cells (HPCs) from older humans. In the elderly, HPCs present active oxidative phosphorylation and are pressed to enter cell cycling. However, p53-p21 and p15 cell senescence pathways, associated with telomerase activity deficiency, strong telomere attrition, and oxidative stress, are engaged, thus limiting cell cycling. Moreover, survival of old HPCs is impacted by pyroptosis, an inflammatory form of programmed cell death. Lastly, telomerase activity deficiency and telomere length attrition of old HPCs may be passed on to progeny cells such as naive T lymphocytes, further highlighting the poor hematopoietic potential of the elderly. This pre-senescent profile is characteristic of the multiple intrinsic and extrinsic factors affecting HPCs in elderly individuals and represents a major obstacle in terms of immune reconstitution and efficacy with advanced age.

Authors

Tinhinane Fali, Véronique Fabre-Mersseman, Takuya Yamamoto, Charles Bayard, Laura Papagno, Solène Fastenackels, Rima Zoorab, Richard A. Koup, Jacques Boddaert, Delphine Sauce, Victor Appay

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Abstract

The role of posttranscriptional metabolic gene regulatory programs in diabetes is not well understood. Here, we show that the RNA-binding protein tristetraprolin (TTP) is reduced in the livers of diabetic mice and humans and is transcriptionally induced in response to insulin treatment in murine livers in vitro and in vivo. Liver-specific Ttp-KO (lsTtp-KO) mice challenged with high-fat diet (HFD) have improved glucose tolerance and peripheral insulin sensitivity compared with littermate controls. Analysis of secreted hepatic factors demonstrated that fibroblast growth factor 21 (FGF21) is posttranscriptionally repressed by TTP. Consistent with increased FGF21, lsTtp-KO mice fed HFD have increased brown fat activation, peripheral tissue glucose uptake, and adiponectin production compared with littermate controls. Downregulation of hepatic Fgf21 via an adeno-associated virus–driven shRNA in mice fed HFD reverses the insulin-sensitizing effects of hepatic Ttp deletion. Thus, hepatic TTP posttranscriptionally regulates systemic insulin sensitivity in diabetes through liver-derived FGF21.

Authors

Konrad T. Sawicki, Hsiang-Chun Chang, Jason S. Shapiro, Marina Bayeva, Adam De Jesus, Brian N. Finck, Jason A. Wertheim, Perry J. Blackshear, Hossein Ardehali

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Abstract

Hemodynamic shear force has been implicated as modulating Notch signaling–mediated cardiac trabeculation. Whether the spatiotemporal variations in wall shear stress (WSS) coordinate the initiation of trabeculation to influence ventricular contractile function remains unknown. Using light-sheet fluorescent microscopy, we reconstructed the 4D moving domain and applied computational fluid dynamics to quantify 4D WSS along the trabecular ridges and in the groves. In WT zebrafish, pulsatile shear stress developed along the trabecular ridges, with prominent endocardial Notch activity at 3 days after fertilization (dpf), and oscillatory shear stress developed in the trabecular grooves, with epicardial Notch activity at 4 dpf. Genetic manipulations were performed to reduce hematopoiesis and inhibit atrial contraction to lower WSS in synchrony with attenuation of oscillatory shear index (OSI) during ventricular development. γ-Secretase inhibitor of Notch intracellular domain (NICD) abrogated endocardial and epicardial Notch activity. Rescue with NICD mRNA restored Notch activity sequentially from the endocardium to trabecular grooves, which was corroborated by observed Notch-mediated cardiomyocyte proliferations on WT zebrafish trabeculae. We also demonstrated in vitro that a high OSI value correlated with upregulated endothelial Notch-related mRNA expression. In silico computation of energy dissipation further supports the role of trabeculation to preserve ventricular structure and contractile function. Thus, spatiotemporal variations in WSS coordinate trabecular organization for ventricular contractile function.

Authors

Juhyun Lee, Vijay Vedula, Kyung In Baek, Junjie Chen, Jeffrey J. Hsu, Yichen Ding, Chih-Chiang Chang, Hanul Kang, Adam Small, Peng Fei, Cheng-ming Chuong, Rongsong Li, Linda Demer, René R. Sevag Packard, Alison L. Marsden, Tzung K. Hsiai

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Abstract

Recent years have witnessed the groundbreaking success of immune checkpoint blockage (ICB) in metastasized malignant melanoma. However, biomarkers predicting the response to ICB are still urgently needed. In the present study, we investigated CTLA4 promoter methylation (mCTLA4) in 470 malignant melanoma patients from The Cancer Genome Atlas (non-ICB cohort) and in 50 individuals with metastasized malignant melanomas under PD-1/CTLA-4–targeted immunotherapy (ICB cohort). mCTLA4 levels were quantified using the Infinium HumanMethylation450 BeadChip (non-ICB cohort) and methylation-specific quantitative real-time PCR in DNA formalin-fixed and paraffin-embedded tissues (ICB cohort). Methylation levels were associated with molecular and clinicopathological variables and analyzed with respect to response (irRECIST) and overall survival. CTLA-4 mRNA and mCTLA4 showed a significant inverse correlation (non-ICB cohort: Spearman’s ρ = –0.416, P < 0.001). In ICB-treated melanoma patients, low mCTLA4 was further strongly correlated with response to therapy (P = 0.009, ANOVA) and overall survival (hazard ratio = 2.06 [95% CI: 1.29–3.29], P = 0.003). Our data strongly support the assumption that mCTLA4 predicts response to both anti–PD-1 and anti–CTLA-4 targeted ICB in melanoma and provides paramount information for the selection of patients likely to respond to ICB.

Authors

Diane Goltz, Heidrun Gevensleben, Timo J. Vogt, Joern Dietrich, Carsten Golletz, Friedrich Bootz, Glen Kristiansen, Jennifer Landsberg, Dimo Dietrich

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Abstract

Success of immune checkpoint inhibitors in advanced non-small-cell lung cancer (NSCLC) has invigorated their use in the neoadjuvant setting for early-stage disease. However, the cellular and molecular mechanisms of the early immune responses to therapy remain poorly understood. Through an integrated analysis of early-stage NSCLC patients and a Kras mutant mouse model, we show a prevalent programmed cell death 1/programmed cell death 1 ligand 1 (PD-1/PD-L1) axis exemplified by increased intratumoral PD-1+ T cells and PD-L1 expression. Notably, tumor progression was associated with spatiotemporal modulation of the immune microenvironment with dominant immunosuppressive phenotypes at later phases of tumor growth. Importantly, PD-1 inhibition controlled tumor growth, improved overall survival, and reprogrammed tumor-associated lymphoid and myeloid cells. Depletion of T lymphocyte subsets demonstrated synergistic effects of those populations on PD-1 inhibition of tumor growth. Transcriptome analyses revealed T cell subset–specific alterations corresponding to degree of response to the treatment. These results provide insights into temporal evolution of the phenotypic effects of PD-1/PD-L1 activation and inhibition and motivate targeting of this axis early in lung cancer progression.

Authors

Geoffrey J. Markowitz, Lauren S. Havel, Michael J.P. Crowley, Yi Ban, Sharrell B. Lee, Jennifer S. Thalappillil, Navneet Narula, Bhavneet Bhinder, Olivier Elemento, Stephen T.C. Wong, Dingcheng Gao, Nasser K. Altorki, Vivek Mittal

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Abstract

The peripheral blood represents only a small fraction of the total number of lymphocytes in the body. To develop a more thorough understanding of T cell dynamics, including the effects of SIV/SHIV/HIV infection on immune cell depletion and immune reconstitution following combination antiretroviral therapy (cART), one needs to utilize approaches that allow direct visualization of lymphoid tissues. In the present study, noninvasive in vivo imaging of the CD4+ T cell pool has revealed that the timing of the CD4+ T cell pool reconstitution following initiation of ART in SIV-infected nonhuman primates (NHPs) appears seemingly stochastic among clusters of lymph nodes within the same host. At 4 weeks following initiation or interruption of cART, the changes observed in peripheral blood (PB) are primarily related to changes in the whole-body CD4 pool rather than changes in lymphocyte trafficking. Lymph node CD4 pools in long-term antiretroviral-treated and plasma viral load–suppressed hosts appear suboptimally reconstituted compared with healthy controls, while splenic CD4 pools appear similar between the 2 groups.

Authors

Michele Di Mascio, Sharat Srinivasula, Insook Kim, Gorka Duralde, Alexis St. Claire, Paula DeGrange, Marisa St. Claire, Keith A. Reimann, Erin E. Gabriel, Jorge Carrasquillo, Richard C. Reba, Chang Paik, Henry C. Lane

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Abstract

Persistent fibrosis in multiple organs is the hallmark of systemic sclerosis (SSc). Recent genetic and genomic studies implicate TLRs and their damage-associated molecular pattern (DAMP) endogenous ligands in fibrosis. To test the hypothesis that TLR4 and its coreceptor myeloid differentiation 2 (MD2) drive fibrosis persistence, we measured MD2/TLR4 signaling in tissues from patients with fibrotic SSc, and we examined the impact of MD2 targeting using a potentially novel small molecule. Levels of MD2 and TLR4, and a TLR4-responsive gene signature, were enhanced in SSc skin biopsies. We developed a small molecule that selectively blocks MD2, which is uniquely required for TLR4 signaling. Targeting MD2/TLR4 abrogated inducible and constitutive myofibroblast transformation and matrix remodeling in fibroblast monolayers, as well as in 3-D scleroderma skin equivalents and human skin explants. Moreover, the selective TLR4 inhibitor prevented organ fibrosis in several preclinical disease models and mouse strains, and it reversed preexisting fibrosis. Fibroblast-specific deletion of TLR4 in mice afforded substantial protection from skin and lung fibrosis. By comparing experimentally generated fibroblast TLR4 gene signatures with SSc skin biopsy gene expression datasets, we identified a subset of SSc patients displaying an activated TLR4 signature. Together, results from these human and mouse studies implicate MD2/TLR4-dependent fibroblast activation as a key driver of persistent organ fibrosis. The results suggest that SSc patients with high TLR4 activity might show optimal therapeutic response to selective inhibitors of MD2/TLR4 complex formation.

Authors

Swati Bhattacharyya, Wenxia Wang, Wenyi Qin, Kui Cheng, Sara Coulup, Sherry Chavez, Shuangshang Jiang, Kirtee Raparia, Lucia Maria V. De Almeida, Christian Stehlik, Zenshiro Tamaki, Hang Yin, John Varga

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Abstract

The genomic integration of HIV into cells results in long-term persistence of virally infected cell populations. This integration event acts as a heritable mark that can be tracked to monitor infected cells that persist over time. Previous reports have documented clonal expansion in people and have linked them to proto-oncogenes; however, their significance or contribution to the latent reservoir has remained unclear. Here, we demonstrate that a directed pattern of clonal expansion occurs in vivo, specifically in gene pathways important for viral replication and persistence. These biological processes include cellular division, transcriptional regulation, RNA processing, and posttranslational modification pathways. This indicates preferential expansion when integration events occur within genes or biological pathways beneficial for HIV replication and persistence. Additionally, these expansions occur quickly during unsuppressed viral replication in vivo, reinforcing the importance of early intervention for individuals to limit reservoir seeding of clonally expanded HIV-infected cells.

Authors

Kevin G. Haworth, Lauren E. Schefter, Zachary K. Norgaard, Christina Ironside, Jennifer E. Adair, Hans-Peter Kiem

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Abstract

Recent advances in the management of cystic fibrosis (CF) target underlying defects in the CF transmembrane conductance regulator (CFTR) protein, but efficacy analyses remain limited to specific genotype–based subgroups. Patient-derived model systems may therefore aid in expanding access to these drugs. Brushed human nasal epithelial cells (HNEs) are an attractive tissue source, but it remains unclear how faithfully they recapitulate human bronchial epithelial cell (HBE) CFTR activity. We examined this gap using paired, brushed HNE/HBE samples from pediatric CF subjects with a wide variety of CFTR mutations cultured at the air-liquid interface. Growth and structural characteristics for the two cell types were similar, including differentiation into mature respiratory epithelia. In electrophysiologic analysis, no correlation was identified between nasal and bronchial cultures in baseline resistance or epithelial sodium channel (ENaC) activity. Conversely, robust correlation was demonstrated between nasal and bronchial cultures in both stimulated and inhibited CFTR activity. There was close correlation in modulator-induced change in CFTR activity, and CFTR activity in both cell types correlated with in vivo sweat chloride measurements. These data confirm that brushed HNE cell cultures recapitulate the functional CFTR characteristics of HBEs with fidelity and are therefore an appropriate noninvasive HBE surrogate for individualized CFTR analysis.

Authors

John J. Brewington, Erin T. Filbrandt, F.J. LaRosa III, Jessica D. Moncivaiz, Alicia J. Ostmann, Lauren M. Strecker, John P. Clancy

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Abstract

T cells engineered to express chimeric antigen receptors (CARs) against B cell antigens are being investigated as cellular immunotherapies. Similar approaches designed to target T cell malignancies have been hampered by the critical issue of T-on-T cytotoxicity, whereby fratricide or self-destruction of healthy T cells prohibits cell product manufacture. To date, there have been no reports of T cells engineered to target the definitive T cell marker, CD3 (3CAR). Recent improvements in gene editing now provide access to efficient disruption of such molecules on T cells, and this has provided a route to generation of 3CAR, CD3-specific CAR T cells. T cells were transduced with a lentiviral vector incorporating an anti-CD3ε CAR derived from OKT3, either before or after TALEN-mediated disruption of the endogenous TCRαβ/CD3 complex. Only transduction after disrupting assembly of TCRαβ/CD3 yielded viable 3CAR T cells, and these cultures were found to undergo self-enrichment for 3CAR+TCR–CD3– T cells without any further processing. Specific cytotoxicity against CD3ε was demonstrated against primary T cells and against childhood T cell acute lymphoblastic leukemia (T-ALL). 3CAR T cells mediated potent antileukemic effects in a human/murine chimeric model, supporting the application of cellular immunotherapy strategies against T cell malignancies. 3CAR provides a bridging strategy to achieve T cell eradication and leukemic remission ahead of conditioned allogeneic stem cell transplantation.

Authors

Jane Rasaiyaah, Christos Georgiadis, Roland Preece, Ulrike Mock, Waseem Qasim

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Abstract

Tenofovir gel and dapivirine ring provided variable HIV protection in clinical trials, reflecting poor adherence and possibly biological factors. We hypothesized that vaginal microbiota modulates pharmacokinetics and tested the effects of pH, individual bacteria, and vaginal swabs from women on pharmacokinetics and antiviral activity. Tenofovir, but not dapivirine, uptake by human cells was reduced as pH increased. Lactobacillus crispatus actively transported tenofovir leading to a loss in drug bioavailability and culture supernatants from Gardnerella vaginalis, but not Atopobium vaginae, blocked tenofovir endocytosis. The inhibition of endocytosis mapped to adenine. Adenine increased from 65.5 μM in broth to 246 μM in Gardnerella, but decreased to 9.5 μM in Atopobium supernatants. This translated into a decrease in anti-HIV activity when Gardnerella supernatants or adenine were added to cultures. Dapivirine was also impacted by microbiota, as drug bound irreversibly to bacteria, resulting in decreased antiviral activity. When drugs were incubated with vaginal swabs, 30.7% ± 5.7% of dapivirine and 63.9% ± 8.8% of tenofovir were recovered in supernatants after centrifugation of the bacterial cell pellet. In contrast, no impact of microbiota on the pharmacokinetics of the prodrugs, tenofovir disoproxil fumarate or tenofovir alafenamide, was observed. Together, these results demonstrate that microbiota may impact pharmacokinetics and contribute to inconsistent efficacy.

Authors

Ekaterina Taneva, Shada Sinclair, Pedro M.M. Mesquita, Brian Weinrick, Scott A. Cameron, Natalia Cheshenko, Kerry Reagle, Bruce Frank, Sujatha Srinivasan, David Fredricks, Marla J. Keller, Betsy C. Herold

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Abstract

BACKGROUND. Necroptosis is a form of programmed necrotic cell death that is rapidly emerging as an important pathophysiological pathway in numerous disease states. Necroptosis is dependent on receptor-interacting protein kinase 3 (RIPK3), a protein shown to play an important role in experimental models of critical illness. However, there is limited clinical evidence regarding the role of extracellular RIPK3 in human critical illness. METHODS. Plasma RIPK3 levels were measured in 953 patients prospectively enrolled in 5 ongoing intensive care unit (ICU) cohorts in both the USA and Korea. RIPK3 concentrations among groups were compared using prospectively collected phenotypic and outcomes data. RESULTS. In all 5 cohorts, extracellular RIPK3 levels in the plasma were higher in patients who died in the hospital compared with those who survived to discharge. In a combined analysis, increasing RIPK3 levels were associated with elevated odds of in-hospital mortality (odds ratio [OR] 1.7 for each log10-unit increase in RIPK3 level, P < 0.0001). When adjusted for baseline severity of illness, the OR for in-hospital mortality remained statistically significant (OR 1.33, P = 0.007). Higher RIPK3 levels were also associated with more severe organ failure. CONCLUSIONS. Our findings suggest that elevated levels of RIPK3 in the plasma of patients admitted to the ICU are associated with in-hospital mortality and organ failure. FUNDING. Supported by NIH grants P01 HL108801, R01 HL079904, R01 HL055330, R01 HL060234, K99 HL125899, and KL2TR000458-10. Supported by Samsung Medical Center grant SMX1161431.

Authors

Kevin C. Ma, Edward J. Schenck, Ilias I. Siempos, Suzanne M. Cloonan, Eli J. Finkelzstein, Maria A. Pabon, Clara Oromendia, Karla V. Ballman, Rebecca M. Baron, Laura E. Fredenburgh, Angelica Higuera, Jin Young Lee, Chi Ryang Chung, Kyeongman Jeon, Jeong Hoon Yang, Judie A. Howrylak, Jin-Won Huh, Gee Young Suh, Augustine M.K. Choi

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Abstract

Coinhibitory receptors play an important role in the prevention of autoimmune diseases, such as systemic lupus erythematosus (SLE), by limiting T cell activation. B and T lymphocyte attenuator (BTLA) is an inhibitory receptor, similar to cytotoxic T lymphocyte–associated protein 4 (CTLA-4) and programmed death 1 (PD1), that negatively regulates the immune response. The role of BTLA in the pathogenesis of autoimmune diseases in humans and, more specifically, in SLE is largely unknown. We investigated BTLA expression on various T cell subsets, and we did not observe significant variations of BTLA expression between lupus patients and healthy controls. However, the enhancement of BTLA expression after activation was significantly lower in SLE patients compared with that in healthy controls. Furthermore, we found an impaired capacity of BTLA to inhibit T cell activation in SLE due to a poor BTLA recruitment to the immunological synapse following T cell stimulation. Finally, we demonstrated that defective BTLA function can be corrected by restoring intracellular trafficking and by normalizing the lipid metabolism in lupus CD4+ T cells. Collectively, our results evidence that the BTLA signaling pathway is altered in SLE T cells and highlight the potential of targeting this pathway for the development of new therapeutic strategies in lupus.

Authors

Matthieu Sawaf, Jean-Daniel Fauny, Renaud Felten, Flora Sagez, Jacques-Eric Gottenberg, Hélène Dumortier, Fanny Monneaux

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