Primary Graft Dysfunction (PGD) is the predominant cause of early graft loss following lung transplantation. We recently demonstrated that donor pulmonary intravascular non-classical monocytes (NCM) initiate neutrophil recruitment. Simultaneously, host-origin classical monocytes (CM) permeabilize the vascular endothelium to allow neutrophil extravasation necessary for PGD. Here, we show that a CCL2-CCR2 axis is necessary for CM recruitment. Surprisingly, although intravital imaging and multichannel flowcytometry revealed that depletion of donor NCM abrogated CM recruitment, single-cell RNA-seq identified donor alveolar macrophages (AM) as predominant CCL2 secretors. Unbiased transcriptomic analysis of murine tissues combined with murine knockouts and chimeras indicated that IL1β production by donor NCM was responsible for the early activation of AM and CCL2 release. IL1β production by NCM was NLRP3 inflammasome-dependent and inhibited by treatment with a clinically approved sulphonylurea. Production of CCL2 in the donor AM occurred through IL1R-dependent activation of the PKC and NFκB-pathway. Accordingly, we show that IL1β-dependent paracrine interaction between donor NCM and AM leads to recruitment of recipient CM necessary for PGD. Since depletion of donor NCM, IL1β or IL1R antagonism, and inflammasome inhibition, abrogated recruitment of CM as well as PGD, and are feasible using FDA-approved compounds, our findings may have potential for clinical translation.
Chitaru Kurihara, Emilia Lecuona, Qiang Wu, Wenbin Yang, Felix L. Nunez-Santana, Mahzad Akbarpour, Xianpeng Liu, Ziyou Ren, Wenjun Li, Melissa Querrey, Sowmya Ravi, Megan L. Anderson, Emily Cerier, Haiying Sun, Megan E. Kelly, Hiam Abdala-Valencia, Ali Shilatifard, Thalachallour Mohanakumar, G.R. Scott Budinger, Daniel Kreisel, Ankit Bharat
X-linked neutropenia (XLN) is caused by gain-of-function mutations in the actin regulator Wiskott-Aldrich Syndrome protein (WASp). XLN patients have reduced numbers of cytotoxic cells in peripheral blood, however, their capacity to kill tumor cells remains to be determined. Here, we examined NK and T cells from two XLN patients harboring the activating WASpL270P mutation. XLN patient NK and T cells had increased Granzyme B content and elevated degranulation and IFNγ production when compared to healthy control cells. Murine WASpL272P NK and T cells formed stable synapses with YAC-1 tumor cells and anti-CD3/CD28 coated beads, respectively. WASpL272P T cells mice had normal degranulation and cytokine response whereas WASpL272P NK cells showed an enhanced response. Imaging experiments revealed that while WASpL272P CD8 T cells had increased accumulation of actin upon TCR activation, WASpL272P NK cells had normal actin accumulation at lytic synapses triggered through NKp46 signaling but had impaired response to LFA-1 engagement. When compared to WT mice, WASpL272P mice showed reduced growth of B16 melanoma and increased capacity to reject MHC class I-deficient cells. Together, our data suggests that cytotoxic cells with constitutively active WASp have an increased capacity to respond to and kill tumor cells.
Joanna S. Kritikou, Mariana M.S. Oliveira, Julien Record, Mezida B. Saeed, Saket M. Nigam, Minghui He, Marton Keszei, Arnika K. Wagner, Hanna Brauner, Anton Sendel, Saikiran K. Sedimbi, Stamatina Rentouli, David P. Lane, Scott B. Snapper, Klas Kärre, Peter Vandenberghe, Jordan S. Orange, Lisa S. Westerberg
Studies of human hepatitis B virus (HBV) immune pathogenesis are hampered by limited access to liver tissues and technologies for detailed analyses. Here, utilizing imaging mass cytometry (IMC) to simultaneously detect 30 immune, viral and structural markers in liver biopsies from patients with HBeAg+ chronic hepatitis B, we provide novel comprehensive visualization, quantitation and phenotypic characterizations of hepatic adaptive and innate immune subsets that correlated with hepatocellular injury, histological fibrosis and age. We further show marked correlations between adaptive and innate immune cell frequencies and phenotype, highlighting complex immune interactions within the hepatic microenvironment with relevance to HBV pathogenesis.
Daniel Traum, Yue J. Wang, Kathleen B. Schwarz, Jonathan Schug, David K.H. Wong, Harry L.A. Janssen, Norah A. Terrault, Mandana Khalili, Abdus S. Wahed, Karen F. Murray, Philip Rosenthal, Simon C. Ling, Norberto Rodriguez-Baez, Richard K. Sterling, Daryl T.Y. Lau, Timothy M. Block, Michael D. Feldman, Emma E. Furth, William M. Lee, David E. Kleiner, Anna S. Lok, Klaus H. Kaestner, Kyong-Mi Chang
Comorbid medical illnesses, such as obesity and diabetes, are associated with more severe COVID-19, hospitalization, and death. However, the role of the immune system in mediating these clinical outcomes has not been determined. We used multi-parameter flow cytometry and systems serology to comprehensively profile the functions of T cells and antibodies targeting spike, nucleocapsid, and envelope proteins in a convalescent cohort of COVID-19 subjects who were either hospitalized (n=20) or not hospitalized (n=40). To avoid confounding, subjects were matched by age, sex, ethnicity, and date of symptom onset. Surprisingly, we found that the magnitude and functional breadth of virus-specific CD4 T cell and antibody responses were consistently higher among hospitalized subjects, particularly those with medical comorbidities. However, an integrated analysis identified more coordination between polyfunctional CD4 T-cells and antibodies targeting the S1 domain of spike among subjects that were not hospitalized. These data reveal a functionally diverse and coordinated response between T cells and antibodies targeting SARS-CoV-2, which is reduced in the presence of comorbid illnesses that are known risk factors for severe COVID-19.
Krystle K.Q. Yu, Stephanie Fischinger, Malisa T. Smith, Caroline Atyeo, Deniz Cizmeci, Caitlin R. Wolf, Erik D. Layton, Jennifer K. Logue, Melissa S. Aguilar, Kiel Shuey, Carolin Loos, Jingyou Yu, Nicholas M. Franko, Robert Y. Choi, Anna Wald, Dan H. Barouch, David M. Koelle, Douglas Lauffenburger, Helen Y. Chu, Galit Alter, Chetan Seshadri
The drive to withstand environmental stresses and defend against invasion is a universal trait extant in all forms of life. While numerous canonical signaling cascades have been characterized in detail, it remains unclear how these pathways interface to generate coordinated responses to diverse stimuli. To dissect these connections, we follow heparanase (HPSE), a protein best known for its endoglycosidic activity at the extracellular matrix but recently recognized to drive various forms of late stage disease through unknown mechanisms. Using herpes simplex virus-1 (HSV-1) infection as a model cellular perturbation, we demonstrate that HPSE acts beyond its established enzymatic role to restrict multiple forms of cell-intrinsic defense and facilitate host cell reprogramming by the invading pathogen. We reveal that cells devoid of HPSE are innately resistant to infection and counteract viral takeover through multiple amplified defense mechanisms. With a unique grasp of the fundamental processes of transcriptional regulation and cell death, HPSE represents a potent cellular intersection with broad therapeutic potential.
Alex Agelidis, Benjamin A. Turturice, Rahul K. Suryawanshi, Tejabhiram Yadavalli, Dinesh Jaishankar, Joshua Ames, James Hopkins, Lulia Koujah, Chandrashekhar D. Patil, Satvik R. Hadigal, Evan J. Kyzar, Anaamika Campeau, Jacob M. Wozniak, David J. Gonzalez, Israel Vlodavsky, Jin-ping Li, David L. Perkins, Patricia W. Finn, Deepak Shukla
The splenic microenvironment regulates hematopoietic stem and progenitor cell (HSPC) function, particularly during demand-adapted hematopoiesis, however practical strategies to enhance splenic support of transplanted HSPCs have proven elusive. We have previously demonstrated that inhibiting 15-hydroxyprostaglandin dehydrogenase (15-PGDH), using the small molecule (+)SW033291 (PGDHi), increases bone marrow (BM) prostaglandin E2 (PGE2) levels, expands HSPC numbers, and accelerates hematologic reconstitution following BM transplantation (BMT) in mice. Here we demonstrate that the splenic microenvironment, specifically 15-PGDH high-expressing macrophages (MΦs), megakaryocytes (MKs), and mast cells (MCs), regulates steady-state hematopoiesis and potentiates recovery after BMT. Notably, PGDHi-induced neutrophil, platelet, and HSPC recovery were highly attenuated in splenectomized mice. PGDHi induced non-pathologic splenic extramedullary hematopoiesis at steady-state, and pre-transplant PGDHi enhanced the homing of transplanted cells to the spleen. 15-PGDH enzymatic activity localized specifically to MΦs, MK lineage cells, and MCs, identifying these cell types as likely coordinating the impact of PGDHi on splenic HSPCs. These findings suggest that 15-PGDH expression marks novel HSC niche cell types that regulate hematopoietic regeneration. Therefore, PGDHi provides a well-tolerated strategy to therapeutically target multiple HSC niches and to promote hematopoietic regeneration and improve clinical outcomes of BMT.
Julianne N.P. Smith, Dawn M. Dawson, Kelsey F. Christo, Alvin P. Jogasuria, Mark J. Cameron, Monika I. Antczak, Joseph M. Ready, Stanton L. Gerson, Sanford D. Markowitz, Amar B. Desai
The liver is an immune-privileged organ that can deactivate autoreactive T cells. Yet in autoimmune hepatitis (AIH), autoreactive T cells can defy hepatic control and attack the liver. To elucidate how tolerance to self-antigens is lost during AIH pathogenesis, we generated a spontaneous mouse model of AIH, based on recognition of an MHC class II-restricted model peptide in hepatocytes by autoreactive CD4 T cells. We find that the hepatic peptide was not expressed in the thymus leading to deficient thymic deletion and resulting in peripheral abundance of autoreactive CD4 T cells. In the liver, autoreactive CD4 effector T cells accumulated within portal ectopic lymphoid structures and maturated towards pathogenic IFNγ and TNF co-producing cells. Expansion and pathogenic maturation of autoreactive effector T cells was enabled by a selective increase of plasticity and instability of autoantigen-specific Tregs, but not of non-specific Tregs. Indeed, antigen-specific Tregs were reduced in frequency and manifested increased IL-17 production, reduced epigenetic demethylation and reduced expression of Foxp3. As a consequence, autoantigen-specific Tregs had a reduced suppressive capacity, as compared to non-specific Tregs. In conclusion, loss of tolerance and the pathogenesis of AIH were enabled by combined failure of thymic deletion and peripheral regulation.
Max Preti, Lena Schlott, David Lübbering, Daria Krzikalla, Anna-Lena Müller, Fenja A. Schuran, Tobias Poch, Miriam Schakat, Sören Weidemann, Ansgar W. Lohse, Christina Weiler-Normann, Marcial Sebode, Dorothee Schwinge, Christoph Schramm, Antonella Carambia, Johannes Herkel
Regulatory T (Treg) cells orchestrate resolution and repair of acute lung inflammation and injury following viral pneumonia. Compared with younger patients, older individuals experience impaired recovery and worse clinical outcomes after severe viral infections, including influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Whether age is a key determinant of Treg cell pro-repair function following lung injury remains unknown. Here, we show that aging results in a cell-autonomous impairment of reparative Treg cell function following experimental influenza pneumonia. Transcriptional and DNA methylation profiling of sorted Treg cells provide insight into the mechanisms underlying their age-related dysfunction, with Treg cells from aged mice demonstrating both loss of reparative programs and gain of maladaptive programs. Novel strategies that restore youthful Treg cell functional programs could be leveraged as therapies to improve outcomes among older individuals with severe viral pneumonia.
Luisa Morales-Nebreda, Kathryn A. Helmin, Manuel A. Torres Acosta, Nikolay S. Markov, Jennifer Yuan-Shih Hu, Anthony M. Joudi, Raul Piseaux-Aillon, Hiam Abdala-Valencia, Yuliya Politanska, Benjamin D. Singer
Ventilation throughout life is dependent upon the formation of pulmonary alveoli which create an extensive surface area wherein the close apposition of respiratory epithelium and endothelial cells of the pulmonary microvascular enables efficient gas exchange. Morphogenesis of the alveoli initiates at late gestation in humans and the early postnatal period in the mouse. Alveolar septation are directed by complex signaling interactions among multiple cell types. Herein, we demonstrate that the expression of insulin-like growth factor 1 receptor (Igf1r) by a subset of pulmonary fibroblasts is required for normal alveologenesis in mice. Postnatal deletion of Igf1r caused alveolar simplification, disrupting alveolar elastin networks and extracellular matrix without altering myofibroblast differentiation or proliferation. Loss of Igf1r impaired contractile properties of lung myofibroblasts, inhibited myosin light chain (MLC) phosphorylation and mechanotransductive nuclear YAP activity. Activation of p-AKT, p-MLC and nuclear YAP in myofibroblasts was dependent on Igf1r. Pharmacologic activation of AKT enhanced MLC phosphorylation, increased YAP activation and ameliorated alveolar simplification in vivo. IGF1R controls mechanosignaling in myofibroblasts required for lung alveologenesis.
Hua He, John Snowball, Fei Sun, Cheng-Lun Na, Jeffrey A. Whitsett
Functional dyspepsia (FD) is associated with both chronic gastrointestinal distress and anxiety and depression. Here, we hypothesized that aberrant gastric signals, transmitted by the vagus nerve, may alter key brain regions modulating affective and pain behavior. Using a previously validated rat model of FD characterized by gastric hypersensitivity, depression- and anxiety-like behavior, we found that vagal activity in response to gastric distention was increased in FD rats. The FD phenotype was associated with gastric mast cell hyperplasia and increased expression of corticotrophin-releasing factor (CRF) and decreased brain-derived neurotrophic factor in the central amygdala. Subdiaphragmatic vagotomy reversed these changes and restored affective behavior to that of controls. Vagotomy partially attenuated pain responses to gastric distention, which may be mediated by central reflexes in the periaqueductal gray, as determined by local injection of lidocaine. Ketotifen, a mast cell stabilizer, reduced vagal hypersensitivity, normalized affective behavior and attenuated gastric hyperalgesia. In conclusion, vagal activity, partially driven by gastric mast cells, induces long-lasting changes in CRF signaling in the amygdala that may be responsible for enhanced pain and anxiety- and depression-like behaviors. Together, these results support a “bottom-up” pathway involving the gut-brain axis in the pathogenesis of both gastric pain and psychiatric co-morbidity in FD.
Zachary A. Cordner, Qian Li, Liansheng Liu, Kellie L. Tamashiro, Aditi Bhargava, Timothy H. Moran, Pankaj J. Pasricha
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