Browsing by Subject "DENDRITIC CELLS"

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  • Martikainen, Maria-Viola; Rönkkö, Teemu J.; Schaub, Bianca; Täubel, Martin; Gu, Cheng; Wong, Gary W. K.; Li, Jing; Pekkanen, Juha; Komppula, Mika; Hirvonen, Maija-Riitta; Jalava, Pasi I.; Roponen, Marjut (2018)
    Background Studies conducted in farm environments suggest that diverse microbial exposure promotes children's lung health. The underlying mechanisms are unclear, and the development of asthma-preventive strategies has been delayed. More comprehensive investigation of the environment-induced immunoregulation is required for better understanding of asthma pathogenesis and prevention. Exposure to air pollution, including particulate matter (PM), is a risk factor for asthma, thus providing an excellent counterpoint for the farm-effect research. Lack of comparable data, however, complicates interpretation of the existing information. We aimed to explore the immunoregulatory effects of cattle farm dust (protective, Finland) and urban air PM (high-risk, China) for the first time using identical research methods. Methods We stimulated PBMCs of 4-year-old children (N = 18) with farm dust and size-segregated PM and assessed the expression of immune receptors CD80 and ILT4 on dendritic cells and monocytes as well as cytokine production of PBMCs. Environmental samples were analysed for their composition. Results Farm dust increased the percentage of cells expressing CD80 and the cytokine production of children's immune cells, whereas PM inhibited the expression of important receptors and the production of soluble mediators. Although PM samples induced parallel immune reactions, the size-fraction determined the strength of the effects. Conclusions Our study demonstrates the significance of using the same research framework when disentangling shared and distinctive immune pathways operating in different environments. Observed stimulatory effects of farm dust and inhibitory effects of PM could shape responses towards respiratory pathogens and allergens, and partly explain differences in asthma prevalence between studied environments.
  • Smillie, Christopher S.; Biton, Moshe; Ordovas-Montanes, Jose; Sullivan, Ken M.; Burgin, Grace; Graham, Daniel B.; Herbst, Rebecca H.; Rogel, Noga; Slyper, Michel; Waldman, Julia; Sud, Malika; Andrews, Elizabeth; Velonias, Gabriella; Haber, Adam L.; Jagadeesh, Karthik; Vickovic, Sanja; Yao, Junmei; Stevens, Christine; Dionne, Danielle; Nguyen, Lan T.; Villani, Alexandra-Chloe; Hofree, Matan; Creasey, Elizabeth A.; Huang, Hailiang; Rozenblatt-Rosen, Orit; Garber, John J.; Khalili, Hamed; Desch, A. Nicole; Daly, Mark J.; Ananthakrishnan, Ashwin N.; Shalek, Alex K.; Xavier, Ramnik J.; Regev, Aviv (2019)
    Genome-wide association studies (GWAS) have revealed risk alleles for ulcerative colitis (UC). To understand their cell type specificities and pathways of action, we generate an atlas of 366,650 cells from the colon mucosa of 18 UC patients and 12 healthy individuals, revealing 51 epithelial, stromal, and immune cell subsets, including BEST4(+) enterocytes, microfold-like cells, and IL13RA2(+)IL11(+) inflammatory fibroblasts, which we associate with resistance to anti-TNF treatment. Inflammatory fibroblasts, inflammatory monocytes, microfold-like cells, and T cells that co-express CD8 and IL-17 expand with disease, forming intercellular interaction hubs. Many UC risk genes are cell type specific and coregulated within relatively few gene modules, suggesting convergence onto limited sets of cell types and pathways. Using this observation, we nominate and infer functions for specific risk genes across GWAS loci. Our work provides a framework for interrogating complex human diseases and mapping risk variants to cell types and pathways.
  • Jha, Sawan Kumar; Rauniyar, Khusbu; Jeltsch, Michael (2018)
    While both blood and lymphatic vessels transport fluids and thus share many similarities, they also show functional and structural differences, which can be used to differentiate them. Specific visualization of lymphatic vessels has historically been and still is a pivot point in lymphatic research. Many of the proteins that are investigated by molecular biologists in lymphatic research have been defined as marker molecules, i.e. to visualize and distinguish lymphatic endothelial cells (LECs) from other cell types, most notably from blood vascular endothelial cells (BECs) and cells of the hematopoietic lineage. Among the factors that drive the developmental differentiation of lymphatic structures from venous endothelium, Prospero homeobox protein 1 (PROX1) is the master transcriptional regulator. PROX1 maintains lymphatic identity also in the adult organism and thus is a universal LEC marker. Vascular endothelial growth factor receptor-3 (VEGFR-3) is the major tyrosine kinase receptor that drives LEC proliferation and migration. The major activator for VEGFR-3 is vascular endothelial growth factor-C (VEGF-C). However, before VEGF-C can signal, it needs to be proteolytically activated by an extracellular protein complex comprised of Collagen and calcium binding EGF domains 1 (CCBE1) protein and the protease A disintegrin and metallopeptidase with thrombospondin type 1 motif 3 (ADAMTS3). This minireview attempts to give an overview of these and a few other central proteins that scientific inquiry has linked specifically to the lymphatic vasculature. It is limited in scope to a brief description of their main functions, properties and developmental roles. (C) 2018 The Author(s). Published by Elsevier GmbH.
  • Houssari, Mahmoud; Dumesnil, Anais; Tardif, Virginie; Kivela, Riikka; Pizzinat, Nathalie; Boukhalfa, Ines; Godefroy, David; Schapman, Damien; Hemanthakumar, Karthik A.; Bizou, Mathilde; Henry, Jean-Paul; Renet, Sylvanie; Riou, Gaetan; Rondeaux, Julie; Anouar, Youssef; Adriouch, Sahil; Fraineau, Sylvain; Alitalo, Kari; Richard, Vincent; Mulder, Paul; Brakenhielm, Ebba (2020)
    Objective: Lymphatics play an essential pathophysiological role in promoting fluid and immune cell tissue clearance. Conversely, immune cells may influence lymphatic function and remodeling. Recently, cardiac lymphangiogenesis has been proposed as a therapeutic target to prevent heart failure after myocardial infarction (MI). We investigated the effects of gene therapy to modulate cardiac lymphangiogenesis post-MI in rodents. Second, we determined the impact of cardiac-infiltrating T cells on lymphatic remodeling in the heart. Approach and Results: Comparing adenoviral versus adeno-associated viral gene delivery in mice, we found that only sustained VEGF (vascular endothelial growth factor)-C(C156S)therapy, achieved by adeno-associated viral vectors, increased cardiac lymphangiogenesis, and led to reduced cardiac inflammation and dysfunction by 3 weeks post-MI. Conversely, inhibition of VEGF-C/-D signaling, through adeno-associated viral delivery of soluble VEGFR3 (vascular endothelial growth factor receptor 3), limited infarct lymphangiogenesis. Unexpectedly, this treatment improved cardiac function post-MI in both mice and rats, linked to reduced infarct thinning due to acute suppression of T-cell infiltration. Finally, using pharmacological, genetic, and antibody-mediated prevention of cardiac T-cell recruitment in mice, we discovered that both CD4(+)and CD8(+)T cells potently suppress, in part through interferon-gamma, cardiac lymphangiogenesis post-MI. Conclusions: We show that resolution of cardiac inflammation after MI may be accelerated by therapeutic lymphangiogenesis based on adeno-associated viral gene delivery of VEGF-C-C156S. Conversely, our work uncovers a major negative role of cardiac-recruited T cells on lymphatic remodeling. Our results give new insight into the interconnection between immune cells and lymphatics in orchestration of cardiac repair after injury.
  • Mina, Michael J.; Kula, Tomasz; Leng, Yumei; Li, Mamie; de Vries, Rory D.; Knip, Mikael; Siljander, Heli; Rewers, Marian; Choy, David F.; Wilson, Mark S.; Larman, H. Benjamin; Nelson, Ashley N.; Griffin, Diane E.; de Swart, Rik L.; Elledge, Stephen J. (2019)
    Measles virus is directly responsible for more than 100,000 deaths yearly. Epidemiological studies have associated measles with increased morbidity and mortality for years after infection, but the reasons why are poorly understood. Measles virus infects immune cells, causing acute immune suppression. To identify and quantify long-term effects of measles on the immune system, we used VirScan, an assay that tracks antibodies to thousands of pathogen epitopes in blood. We studied 77 unvaccinated children before and 2 months after natural measles virus infection. Measles caused elimination of 11 to 73% of the antibody repertoire across individuals. Recovery of antibodies was detected after natural reexposure to pathogens. Notably, these immune system effects were not observed in infants vaccinated against MMR (measles, mumps, and rubella), but were confirmed in measles-infected macaques. The reduction in humoral immune memory after measles infection generates potential vulnerability to future infections, underscoring the need for widespread vaccination.
  • Trevisi, Paolo; Priori, Davide; Jansman, Alfons J. M.; Luise, Diana; Koopmans, Sietse-Jan; Hynönen, Ulla; Palva, Airi; Van Der Meulen, Jan; Bosi, Paolo (2018)
    The development of an early complex gut microbiota may play an important role in the protection against intestinal dysbiosis later in life. The significance of the developed microbiota for gut barrier functionality upon interaction with pathogenic or beneficial bacteria is largely unknown. The transcriptome of differently perfused jejunal loops of 12 caesarian-derived pigs, neonatally associated with microbiota of different complexity, was studied. Piglets received pasteurized sow colostrum at birth (d0), a starter microbiota (Lactobacillus amylovorus (LAM), Clostridium glycolicum, and Parabacteroides) on d1-d3, and a placebo inoculant (simple association, SA) or an inoculant consisting of sow's diluted feces (complex association, CA) on d3-d4. On d 26-37, jejunal loops were perfused for 8 h with either enterotoxigenic Escherichia coli F4 (ETEC), purified F4 fimbriae, LAM or saline control (CTRL). Gene expression of each intestinal loop was analyzed by Affymetrix Porcine Gene 1.1_ST array strips. Gene Set Enrichment Analysis was performed on expression values. Compared to CTRL, 184 and 74; 2 and 139; 2 and 48 gene sets, were up- and down-regulated by ETEC, F4 and LAM, respectively. ETEC up-regulated networks related to inflammatory and immune responses, RNA processing, and mitosis. There was a limited overlap in up-regulated gene sets between ETEC and F4 fimbriae. LAM down-regulated genes related to inflammatory and immune responses, as well as to cellular compound metabolism. In CA pigs, 57 gene sets were up-regulated by CA, while 73 were down-regulated compared to SA. CA up-regulated gene sets related to lymphocyte modulation and to cellular defense in all loop perfusions. In CA pigs, compared to SA pigs, genes for chemokine and cytokine activity and for response to external stimuli were down-regulated in ETEC-perfused loops and up-regulated in CTRL. The results highlight the importance of the nature of neonatal microbial colonization in the response to microbial stimuli later in life.
  • Eguiluz-Gracia, Ibon; Malmström, Kristiina; Dheyauldeen, Sinan Ahmed; Lohi, Jouko; Sajantila, Antti; Aalokken, Ragnhild; Sundaram, Arvind Y. M.; Gilfillan, Gregor D.; Makela, Mika; Baekkevold, Espen S.; Jahnsen, Frode L. (2018)
    Background: Activated T helper type 2 (Th2) cells are believed to play a pivotal role in allergic airway inflammation, but which cells attract and activate Th2 cells locally have not been fully determined. Recently, it was shown in an experimental human model of allergic rhinitis (AR) that activated monocytes rapidly accumulate in the nasal mucosa after local allergen challenge, where they promote recruitment of Th2 cells and eosinophils. Objective: To investigate whether monocytes are recruited to the lungs in paediatric asthma. Methods: Tissue samples obtained from children and adolescents with fatal asthma attack (n = 12), age-matched non-atopic controls (n = 9) and allergen-challenged AR patients (n = 8) were subjected to in situ immunostaining. Results: Monocytes, identified as CD68+S100A8/A9+ cells, were significantly increased in the lower airway mucosa and in the alveoli of fatal asthma patients compared with control individuals. Interestingly, cellular aggregates containing CD68+S100A8/A9+ monocytes obstructing the lumen of bronchioles were found in asthmatics (8 out of 12) but not in controls. Analysing tissue specimens from challenged AR patients, we confirmed that co-staining with CD68 and S100A8/A9 was a valid method to identify recently recruited monocytes. We also showed that the vast majority of accumulating monocytes both in the lungs and in the nasal mucosa expressed matrix metalloproteinase 10, suggesting that this protein may be involved in their migration within the tissue. Conclusions and clinical relevance: Monocytes accumulated in the lungs of children and adolescents with fatal asthma attack. This finding strongly suggests that monocytes are directly involved in the immunopathology of asthma and that these pro-inflammatory cells are potential targets for therapy.
  • Oksaharju, Anna; Kankainen, Matti; Kekkonen, Riina A.; Lindstedt, Ken A.; Kovanen, Petri T.; Korpela, Riitta; Miettinen, Minja (2011)
  • Gao, Yuge; Yao, Xinyu; Zhai, Yumeng; Li, Li; Li, Huini; Sun, Xianqi; Yu, Pei; Xue, Tiankuo; Li, Yuzhen; Hu, Yizhou (2021)
    Psoriasis is the most common skin disease in adults. Current experimental and clinical evidences suggested the infiltrating immune cells could target local skin cells and thus induce psoriatic phenotype. However, recent studies indicated the existence of a potential feedback signaling loop from local resident skin cells to infiltrating immune cells. Here, we deconstructed the full-thickness human skins of both healthy donors and patients with psoriasis vulgaris at single cell transcriptional level, and further built a neural-network classifier to evaluate the evolutional conservation of skin cell types between mouse and human. Last, we systematically evaluated the intrinsic and intercellular molecular alterations of each cell type between healthy and psoriatic skin. Cross-checking with psoriasis susceptibility gene loci, cell-type based differential expression, and ligand-receptor communication revealed that the resident psoriatic skin cells including mesenchymal and epidermis cell types, which specifically harbored the target genes of psoriasis susceptibility loci, intensively evoked the expression of major histocompatibility complex (MHC) genes, upregulated interferon (INF), tumor necrosis factor (TNF) signalling and increased cytokine gene expression for primarily aiming the neighboring dendritic cells in psoriasis. The comprehensive exploration and pathological observation of psoriasis patient biopsies proposed an uncovered immunoregulatory axis from skin local resident cells to immune cells, thus provided a novel insight for psoriasis treatment. In addition, we published a user-friendly website to exhibit the transcriptional change of each cell type between healthy and psoriatic human skin.
  • Kallionpaa, Henna; Laajala, Essi; Oling, Viveka; Harkonen, Taina; Tillmann, Vallo; Dorshakova, Natalya V.; Ilonen, Jorma; Landesmaki, Harri; Knip, Mikael; Lahesmaa, Riitta; Koski, Katriina; Koski, Matti; Ryhanen, Samppa; Siljander, Heli; Hamalainen, Anu-Maaria; Ormisson, Anne; Peet, Aleksandr; Ulich, Valentina; Kuzmicheva, Elena; Mokurov, Sergei; Markova, Svettana; Pylova, Svetlana; Isakova, Marina; Shakurova, Elena; Petrov, Vladimir; Karapetyan, Tatyana; Varlamova, Tatyana; Ilonen, Jorma; Kiviniemi, Minna; Alnek, Kristi; Janson, Helis; Uibo, Raivo; Salum, Tiit; von Mutius, Erika; Weber, Juliane; Ahlfors, Helena; Moulder, Robert; Nieminen, Janne; Ruohtula, Terhi; Vaarala, Outi; Honkanen, Hanna; Hyoty, Heikki; Kondrashova, Anita; Oikarinen, Sami; Harmsen, Hermie J. M.; De Goffau, Marcus C.; Welling, Gjalt; Alahuhta, Kirsi; Korhonen, Tuuli; Virtanen, Suvi M.; DIABIMMUNE Study Grp (2014)
  • Virtakoivu, Reetta; Rannikko, Jenna H.; Viitala, Miro; Vaura, Felix; Takeda, Akira; Lonnberg, Tapio; Koivunen, Jussi; Jaakkola, Panu; Pasanen, Annika; Shetty, Shishir; de Jonge, Maja J. A.; Robbrecht, Debbie; Ma, Yuk Ting; Skyttä, Tanja; Minchom, Anna; Jalkanen, Sirpa; Karvonen, Matti K.; Mandelin, Jami; Bono, Petri; Hollmen, Maija (2021)
    Purpose: Macrophages are critical in driving an immunosuppressive tumor microenvironment that counteracts the efficacy of T-cell-targeting therapies. Thus, agents able to reprogram macrophages toward a proinflammatory state hold promise as novel immunotherapies for solid cancers. Inhibition of the macrophage scavenger receptor Clever-1 has shown benefit in inducing CD8 T-cell-mediated antitumor responses in mouse models of cancer, which supports the clinical development of Clever-1-targeting antibodies for cancer treatment. Patients and Methods: In this study, we analyzed the mode of action of a humanized IgG4 anti-Clever-1 antibody, FP-1305 (bexmarilimab), both in vitro and in patients with heavily pretreated metastatic cancer (n = 30) participating in part 1 (dose-finding) of a phase I/II open-label trial (NCT03733990). We studied the Clever-1 interactome in primary human macrophages in antibody pull-down assays and utilized mass cytometry, RNA sequencing, and cytokine profiling to evaluate FP-1305-induced systemic immune activation in patients with cancer. Results: Our pull-down assays and functional studies indicated that FP-1305 impaired multiprotein vacuolar ATPase-mediated endosomal acidification and improved the ability of macrophages to activate CD8(+)T-cells. In patients with cancer, FP-1305 administration led to suppression of nuclear lipid signaling pathways and a proinflammatory phenotypic switch in blood monocytes. These effects were accompanied by a significant increase and activation of peripheral T-cells with indications of antitumor responses in some patients. Conclusions: Our results reveal a nonredundant role played by the receptor Clever-1 in suppressing adaptive immune cells in humans. We provide evidence that targeting macrophage scavenging activity can promote an immune switch, potentially leading to intratumoral proinflammatory responses in patients with metastatic cancer.
  • Fyhrquist, Nanna (2019)
    Allergic diseases have been increasing to epidemic proportions during the past century, especially in high-income countries. Recent evidence suggests there might be a link between the allergy epidemic and reduced microbial exposures, resulting from a rapidly evolved modern lifestyle, including changed diets, health and hygiene standards, and daily habits. Recently it has become clear that the microbial communities in our respiratory system and our gut, as well as on our skin, may play a key role in shaping our physiology, and influencing our health. We are only beginning to understand the mechanisms by which the human microbiota may be regulating the immune system, and sudden changes in the composition of the microbiota may have profound effects, linked with an increased risk of developing chronic inflammatory disorders, including allergies.
  • Heiniö, Camilla; Havunen, Riikka; Santos, Joao; de Lint, Klaas; Cervera-Carrascon, Victor; Kanerva, Anna; Hemminki, Akseli (2020)
    In order to break tumor resistance towards traditional treatments, we investigate the response of tumor and immune cells to a novel, cytokine-armed oncolytic adenovirus: Ad5/3-d24-E2F-hTNFa-IRES-hIL2 (also known as TILT-123 and OAd.TNFa-IL2). There are several pattern recognition receptors (PRR) that might mediate adenovirus-infection recognition. However, the role and specific effects of each PRR on the tumor microenvironment and treatment outcome remain unclear. Hence, the aim of this study was to investigate the effects of OAd.TNFa-IL2 infection on PRR-mediated danger- and pathogen-associated molecular pattern (DAMP and PAMP, respectively) signaling. In addition, we wanted to see which PRRs mediate an antitumor response and are therefore relevant for optimizing this virotherapy. We determined that OAd.TNFa-IL2 induced DAMP and PAMP release and consequent tumor microenvironment modulation. We show that the AIM2 inflammasome is activated during OAd.TNFa-IL2 virotherapy, thus creating an immunostimulatory antitumor microenvironment.
  • Yang, Kun; He, Yingxia; Park, Chae Gyu; Kang, Young Sun; Zhang, Pei; Han, Yanping; Cui, Yujun; Bulgheresi, Silvia; Anisimov, Andrey P.; Dentovskaya, Svetlana; Ying, Xiaoling; Jiang, Lingyu; Ding, Honghui; Njiri, Olivia Adhiambo; Zhang, Shusheng; Zheng, Guoxing; Xia, Lianxu; Kan, Biao; Wang, Xin; Jing, Huaiqi; Yang, Meiying; Li, Wei; Wang, Yuanzhi; Xiamu, Xiding; Chen, Gang; Ma, Ding; Bartra, Sara Schesser; Plano, Gregory; Klena, John D.; Yang, Ruifu; Skurnik, Mikael; Chen, Tie (2019)
    Yersinia pestis, a Gram-negative bacterium and the etiologic agent of plague, has evolved from Yersinia pseudotuberculosis, a cause of a mild enteric disease. However, the molecular and biological mechanisms of how Y pseudotuberculosis evolved to such a remarkably virulent pathogen, Y pestis, are not clear. The ability to initiate a rapid bacterial dissemination is a characteristic hallmark of Y pestis infection. A distinguishing characteristic between the two Yersinia species is that Y pseudotuberculosis strains possess an O-antigen of lipopolysaccharide (LPS) while Y pestis has lost the O-antigen during evolution and therefore exposes its core LPS. In this study, we showed that Y pestis utilizes its core LPS to interact with SIGNR1 (CD209b), a C-type lectin receptor on antigen presenting cells (APCs), leading to bacterial dissemination to lymph nodes, spleen and liver, and the initiation of a systemic infection. We therefore propose that the loss of O-antigen represents a critical step in the evolution of Y pseudotuberculosis into Y pestis in terms of hijacking APCs, promoting bacterial dissemination and causing the plague.
  • He, Ying-Xia; Ye, Cheng-Lin; Zhang, Pei; Li, Qiao; Park, Chae Gyu; Yang, Kun; Jiang, Ling-Yu; Lv, Yin; Ying, Xiao-Ling; Ding, Hong-Hui; Huang, Hong-Ping; Tembo, John Mambwe; Li, An-Yi; Cheng, Bing; Zhang, Shu-Sheng; Zheng, Guo-Xing; Chen, Shi-Yun; Li, Wei; Xia, Lian-Xu; Kan, Biao; Wang, Xin; Jing, Huai-Qi; Yang, Rui-Fu; Peng, Hua; Fu, Yang-Xin; Klena, John D.; Skurnik, Mikael; Chen, Tie (2019)
    Yersinia pseudotuberculosis is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals. Although the molecular mechanisms for dissemination and infection are unclear, many Gram-negative enteropathogens presumably invade the small intestine via Peyer's patches to initiate dissemination. In this study, we demonstrate that Y. pseudotuberculosis utilizes its lipopolysaccharide (LPS) core to interact with CD209 receptors, leading to invasion of human dendritic cells (DCs) and murine macrophages. These Y. pseudotuberculosis CD209 interactions result in bacterial dissemination to MLNs, spleens, and livers of both wild-type and Peyer's patch-deficient mice. The blocking of the Y. pseudotuberculosis CD209 interactions by expression of 0-antigen and with oligosaccharides reduces infectivity. Based on the well-documented studies in which HIV-CD209 interaction leads to viral dissemination, we therefore propose an infection route for Y. pseudotuberculosis where this pathogen, after penetrating the intestinal mucosal membrane, hijacks the Y. pseudotuberculosis CD209 interaction antigen-presenting cells to reach their target destinations, MLNs, spleens, and livers.