Browsing by Subject "Innate immunity"

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  • Heiskala, Marja; Leidenius, Marjut; Joensuu, Kristiina; Heikkilä, Päivi (2019)
    Macrophages are important for the function of the innate immune system, and in solid tumors, they represent a significant proportion of the tumor mass. Tumor-associated macrophages (TAM) have a M2 phenotype and show a multitude of pro-tumoral functions, promoting tumor cell survival, proliferation, and dissemination. CCL2, synthesized by tumor and stromal cells, initiates a chemokine cascade inducing these processes. We studied by immunohistochemistry (IHC) the frequency of TAMs and CCL2 expressing cells in three groups of primary tumor (PT)-recurrence (R) pairs, where relapse was recorded within 2years (group 1), between 5 and 10years (group 2), and after 10years (group 3). In our study all established breast cancers were heavily infiltrated by CD68 positive cells. Both in PTs and in R lesions the infiltration was more abundant in the peritumoral than in the intratumoral stroma. The mean frequency of M2 marker and CD14 positive cells in the intratumoral stroma and CCL2 expressing tumor cells was higher in the Rs as compared to the corresponding PTs. In PTs, a high frequency of CD14 positive cells and a high expression of CCL2 by tumor cells was associated with an early recurrence. The findings support the current understanding of immune cell orchestrated development, progression and metastatic spread of breast cancer. Our study showed that a high frequency of CCL2 positive tumor cells and CD14 positive TAMs are significant risk factors for rapid tumor recurrence. Potential targets for intervention are discussed.
  • Soderholm, Sandra; Anastasina, Maria; Islam, Mohammad Majharul; Tynell, Janne; Poranen, Minna M.; Bamford, Dennis H.; Stenman, Jakob; Julkunen, Ilkka; Sauliene, Ingrida; De Brabander, Jef K.; Matikainen, Sampsa; Nyman, Tuula A.; Saelens, Xavier; Kainov, Denis (2016)
    Influenza A viruses (IAVs) impact the public health and global economy by causing yearly epidemics and occasional pandemics. Several anti-IAV drugs are available and many are in development. However, the question remains which of these antiviral agents may allow activation of immune responses and protect patients against co- and re-infections. To answer to this question, we analysed immuno-modulating properties of the antivirals saliphenylhalamide (SaliPhe), SNS-032, obatoclax, and gemcitabine, and found that only gemcitabine did not impair immune responses in infected cells. It also allowed activation of innate immune responses in lipopolysaccharide (LPS)- and interferon alpha (IFN alpha)-stimulated macrophages. Moreover, immuno-mediators produced by gemcitabine-treated IAV-infected macrophages were able to prime immune responses in non-infected cells. Thus, we identified an antiviral agent which might be beneficial for treatment of patients with severe viral infections. (C) 2015 The Authors. Published by Elsevier B.V.
  • Jiang, Miao; Österlund, Pamela; Poranen, Minna; Julkunen, Ilkka (2020)
    Mammalian cells express different types of RNA molecules that can be classified as protein coding RNAs (mRNA) and non-coding RNAs (ncRNAs) the latter of which have housekeeping and regulatory functions in cells. Cellular RNAs are not recognized by cellular pattern recognition receptors (PRRs) and innate immunity is not activated. RNA viruses encode and express RNA molecules that usually differ from cell-specific RNAs and they include for instance 5'capped and 5-mono- and triphosphorylated RNAs, small viral RNAs and viral RNA-protein complexes called vRNPs. These molecules are recognized by certain members of Toll-like receptor (TLR) and RIG-I-like receptor (RLR) families leading to activation of innate immune responses and the production of antiviral cytokines, such as type I and type III interferons (IFNs). Virus-specific ssRNA and dsRNA molecules that mimic the viral genomic RNAs or their replication intermediates can efficiently be produced by bacteriophage T7 DNA-dependent RNA polymerase and bacteriophage phi6 RNA-dependent RNA polymerase, respectively. These molecules can then be delivered into mammalian cells and the mechanisms of activation of innate immune responses can be studied. In addition, synthetic viral dsRNAs can be processed to small interfering RNAs (siRNAs) by a Dicer enzyme to produce a swarm of antiviral siRNAs. Here we describe the biology of RNAs, their in vitro production and delivery into mammalian cells as well as how these molecules can be used to inhibit virus replication and to study the mechanisms of activation of the innate immune system.
  • Heinonen, Santtu; Rodriguez-Fernandez, Rosa; Diaz, Alejandro; Oliva Rodriguez-Pastor, Silvia; Ramilo, Octavio; Mejias, Asuncion (2019)
    Of all respiratory viruses that affect infants, respiratory syncytial virus (RSV) and rhinovirus (RV) represent the leading pathogens causing acute disease (bronchiolitis) and are associated with the development of recurrent wheezing and asthma. The immune system in infants is still developing, and several factors contribute to their increased susceptibility to viral infections. These factors include differences in pathogen detection, weaker interferon responses, lack of immunologic memory toward the invading pathogen, and T-cell responses that are balanced to promote tolerance and restrain inflammation. These aspects are reviewed here with a focus on RSV and RV infections.
  • Anastasina, Maria; Le May, Nicolas; Bugai, Andrii; Fu, Yu; Soderholm, Sandra; Gaelings, Lana; Ohman, Tiina; Tynell, Janne; Kyttanen, Suvi; Barboric, Matjaz; Nyman, Tuula A.; Matikainen, Sampsa; Julkunen, Ilkka; Butcher, Sarah J.; Egly, Jean-Marc; Kainov, Denis E. (2016)
    Influenza NS1 protein is an important virulence factor that is capable of binding double-stranded (ds) RNA and inhibiting dsRNA-mediated host innate immune responses. Here we show that NS1 can also bind cellular dsDNA. This interaction prevents loading of transcriptional machinery to the DNA, thereby attenuating IAV-mediated expression of antiviral genes. Thus, we identified a previously undescribed strategy, by which RNA virus inhibits cellular transcription to escape antiviral response and secure its replication. (C) 2016 Elsevier B.V. All rights reserved.
  • Holmberg, Ville; Onkamo, Paivi; Lahtela, Laura Elisa; Lahermo, Paivi; Bedu-Addo, George; Mockenhaupt, Frank P.; Meri, Seppo (2012)
  • Nyman, Tuula A.; Matikainen, Sampsa (2018)
    Viral infections are a major burden to human and animal health. Immune response against viruses consists of innate and adaptive immunity which are both critical for the eradication of the viral infection. The innate immune system is the first line of defense against viral infections. Proper innate immune response is required for the activation of adaptive, humoral and cell-mediated immunity. Macrophages are innate immune cells which have a central role in detecting viral infections including influenza A and human immunodeficiency viruses. Macrophages and other host cells respond to viral infection by modulating their protein expression levels, proteins' posttranslational modifications, as well as proteins' intracellular localization and secretion. Therefore the detailed characterization how viruses dynamically manipulate host proteome is needed for understanding the molecular mechanisms of viral infection. It is critical to identify cellular host factors which are exploited by different viruses, and which are less prone for mutations and could serve as potential targets for novel antiviral compounds. Here, we review how proteomics studies have enhanced our understanding of macrophage response to viral infection with special focus on Influenza A and Human immunodeficiency viruses, and virus infections of swine. (C) 2017 Elsevier B.V. All rights reserved.
  • Nascimento, Gustavo G.; Baelum, Vibeke; Sorsa, Timo; Tervahartiala, Taina; Skottrup, Peter D.; Lopez, Rodrigo (2019)
    Aim: This study aimed to investigate the association between salivary levels of myeloperoxidase (MPO), neutrophil elastase (NE), soluble urokinase-type plasminogen activator receptor (suPAR), matrix metalloproteinase (MMP)-8 and tissue inhibitor of matrix metalloproteinases (TIMP)-1 and gingival inflammation development during an experimental gingivitis study. Methods: A three-week experimental gingivitis study was conducted. Clinical recordings of dental plaque biofilm (Modified Quigley Hein Plaque Index, TQHPI) and gingival inflammation (Modified Gingival Index, MGI) were made at specific time points for each of the 42 participants. Salivary levels of MPO, NE, suPAR, MMP-8 and TIMP-1 at the same time points were measured using distinct immunoassays. For data analysis growth curve modelling was employed to account for the time-varying outcome (MGI score) and the time-varying covariates (salivary marker levels, and TQHPI score). Analyses were stratified according to the MGI-score trajectory groups previously identified as 'fast', respectively 'slow' responders. Results: Overall, higher MGI scores were statistically significantly positively associated with higher levels of MPO, MMP-8 and TIMP-1. Stratified analysis according to inflammation development trajectory group revealed higher levels of salivary MPO, MMP-8 and MMP-8/TIMP-1 ratio among the 'fast' responders than among 'slow' responders. None of the investigated salivary protein markers was associated with a 'slow' inflammation development response. Conclusions: Salivary levels of MPO, MMP-8 and TIMP-1 were associated with the extent and severity of gingival inflammation. While the 'fast' gingival inflammation response was associated with increased levels of MPO, MMP-8 and MMP-8/TIMP-1 ratio, the 'slow' response was not associated with any of the salivary protein markers investigated in this study. Neutrophil activity seems to orchestrate a 'fast' gingival inflammatory response among participants previously primed to gingival inflammation.
  • 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)