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Fenotipske promene izazvane imunizacijom encefalitogenom menjaju funkcije peritonealnih makrofaga u dva soja pacova različite osetljivosti prema indukciji eksperimentalnog autoimunskog encefalomijelitisa (EAE).
Get PDFWe have investigated the phenotype of peritoneal cells and the functions of peritoneal macrophages obtained from experimental autoimmune encephalomyelitis (EAE)-susceptible Dark Agouti (DA) and EAE-resistant Albino Oxford (AO) rat strains on days 1, 3 and 7 post immunization with encephalitogen. Resident peritoneal cells from immunized and non-immunized rats of both strains were subjected to flow cytometric analyzes and after adherence were tested for zymosan phagocytosis, hydrogen peroxide (H2O2) and nitric oxide (NO) production. In non-immunized rats, macrophages from the DA rat strain phagocytosed more zymosan but produced less H2O2 than cells from the AO strain, while both strains produced comparable amounts of NO. Immunization increased phagocytosis in DA rats' cells, but decreased both phagocytosis and H2O2 production in cells from AO rats. Overall higher phagocyte ability in DA rats was associated with a significantly larger population of ED1+ cells (macrophages and dendritic cells), in contrast to a more pronounced expression of ED2 antigen (resident macrophages) on cells from AO rats. Immunization also increased the expression of CD11b molecule on non-resident ED2-macrophages of DA, but not of AO rats. The early and subtle phenotype changes in peritoneal cells of both rat strains might mirror the mechanism contributing to their different sensitivity to the induction of autoimmunity.Ispitivan je fenotip peritonealnih ćelija, kao i funkcije peritonealnih makrofaga, izolovanih od pacova Dark Agouti (DA) soja osetljivog na indukciju eksperimentalnog autoimunskog encefalomijelitisa (EAE) i pacova Albino Oxford (AO) soja koji je rezistentan prema EAE-u, 1, 3. i 7. dana nakon imunizacije encefalitogenom. Rezidentne peritonealne ćelije su ispitivane metodom protočne citofluorometrije, a zatim je nakon adherence testirana njihova sposobnost fagocitoze čestica zimozana i kapacitet produkcije vodonik peroksida (H2O2) i azot monoksida (NO). U neimunizovanih pacova makrofage DA soja su intenzivnije fagocitovale čestice zimozana i imale nižu sposobnost produkcije H2O2 nego ćelije pacova AO soja, ali nije bilo sojnih razlika u sposobnosti produkcije NO. Imunizacija je dovela do povećanja fagocitne sposobnosti makrofaga DA pacova, ali i do smanjenja fagocitoze i produkcije H2O2 makrofaga pacova AO soja. Generalno veću sposobnost fagocitoze u DA pacova prati i značajno veća zastupljenost ED1+ ćelija (koje čine uglavnom makrofage i dendritične ćelije) nasuprot većoj zastupljenosti ED2 antigena (marker rezidentnih makrofaga) na ćelijama pacova AO soja. Imunizacija encefalitogenom je takođe dovela do povećanja ekspresije CD11b molekula na nerezidentnim ED2- ćelijama pacova DA, ali ne i AO soja. Rane i diskretne fenotipske promene na peritonealnim ćelijama pacova oba soja verovatno odslikavaju mehanizme koji doprinose njhovoj različitoj osetljivosti prema indukciji autoimunskih oboljenja
Role of ovarian hormones in age-associated thymic involution revisited
No full textA commonly held view that ovarian hormones are causally involved in age-associated thymic involution has been recently challenged. In particular, their relevance in the progression of thymic involution has been disputed. To reassess this issue 10-month-old rats with well advanced thymic involutive changes were ovariectomized (Ovx), and after 1 month thymic cellularity, thymocyte development and levels of recent thymic emigrants (RTEs) were examined in peripheral blood and spleen. In addition, the distribution of major conventional and regulatory T-cell subsets was analyzed in the same peripheral lymphocyte compartments. Ovariectomy increased thymic weight and cellularity above the levels in both 10-month-old and age-matched controls indicating that ovarian hormone ablation not only prevented further progression of thymic involution, hut also reversed it. The increased thymic cellularity was accompanied by altered thymocyte differentiation/maturation culminating in increased thymic output of nave T cells as indicated by elevated levels of both CD4 + and CD8 + RTEs in peripheral blood and spleen. The changes in T-cell development produced: (i) a disproportional increase in cellularity across thymocyte subsets, so that relative proportions of cells at all maturational stages preceding the CD4 + CD8 + T cell receptor (TCR)alpha beta(low) stage were reduced; the relative numbers of CD4 + CD8 + TCR alpha beta(low) cells entering positive selection and their immediate CD4 + CD8 + TCR alpha beta(high) descendents were increased, while those of the most mature CD4 + CD8 and CD4 CD8 + TCR alpha beta(high) cells remained unaltered; (ii) enhanced cell proliferation across all thymocyte subsets and (iii) reduced apoptosis of cells within the CD4 + CD8 + thymocyte subset. The augmented thymic output of naive T cells in Ovx rats most likely reflected an early disinhibition of thymocyte development followed by increased positive/reduced negative selection, at least partly, due to raised thymocyte surface Thy-1 expression. The greater number of CD4 + CD25 + Foxp3 + cells in both thymus and peripheral blood suggested augmented thymic production of these cells. In addition, an increased CD4 + /CD8 + cell ratio was found in the spleen of Ovx rats. Thus, ovarian hormone ablation led not only to increased diversity of the T-cell repertoire, but also to a new balance among distinct T-cell subsets in the periphery. (C) 2009 Elsevier GmbH. All rights reserved
Retraction notice to: Kojić, M.; Lozo, J.; Jovčić, B.; Strahinić, I.; Fira, Đ.; Topisirović, L. A Successful Use of a New Shuttle Cloning Vector pA13 for the Cloning of the Bacteriocins BacSJ and Acidocin 8912. Archives of Biological Sciences 2010, 62 (2), 231–243. https://doi.org/10.2298/ABS1002231K.
Get PDFRetraction notice to: Kojić, M.; Lozo, J.; Jovčić, B.; Strahinić, I.; Fira, Đ.; Topisirović, L. A Successful Use of a New Shuttle Cloning Vector pA13 for the Cloning of the Bacteriocins BacSJ and Acidocin 8912. Archives of Biological Sciences 2010, 62 (2), 231–243. [https://doi.org/10.2298/ABS1002231K]
The context of tetanus toxoid application influences the outcome of antigen-specific and self-directed humoral immune response
Get PDFResults are presented concerning our attempts to create a suitable model system for studying the connection between microbial antigen (micAg), autoimmunity and autoimmune disease on the basis of hyper-immunization and application of micAg in different contexts. Our research was focused on tetanus toxoid (TTd) as a model micAg. Non-pretreated and complete Freund's adjuvant pretreated BALB/c mice were immunized with high doses of TTd mixed with glycerol or aluminum hydroxide as adjuvants. The main aims of the experiments were to evaluate the properties of induced humoral immune responses, evaluate the pathological potential of induced immune responses and determine possible correlations between the properties of a humoral immune response and its pathological potential. The production of TTd-specific and self-reactive beta(2)-glycoprotein I (beta(2)-GP I)-specific antibodies (Abs) was detected in all groups but with specific, context-related properties. Analysis of pregnancy-related pathology (anti-beta(2)-GP I Abs-associated) showed differences in the pathological potential of the induced immune response. It was demonstrated that severity of pathology is positively correlated to the abundance of IgG that recognizes beta(2)-GP I adsorbed onto phosphatidylserine, and to IgG affinity. Furthermore, it was demonstrated that molecular mimicry, which results in generation of anti-beta(2)-GP I Abs upon TTd immunization, is necessary but not sufficient for the development of pregnancy-related pathology
Choroid Plexus Connexin 43 Expression and Gap Junction Flexibility Are Associated with Clinical Features of Acute EAE
No full textExperimental autoimmune encephalomyelitis (EAE) induced by ventricular injection of antimyelin oligodendrocyte antibodies in DA rats showed severe clinical signs 4 to 5 days after injection. Immunocytochemically, connexin 43 (Cx43) expression increased in the choroid plexus and in the subventricular and subgranular zones of the hippocampus during the development of acute EAE, and decreased after the beginning of the remission phase of the disease. Quantitative computing analysis showed a significantly increased Cx43 expression in the choroid plexus at the peak of the disease. Plaque-pattern expression of the Cx43 in the choroid plexus (CP) of acute EAE correlated with the increased docking and coupling of the Cx43 hemichannels revealed by atomic force microscopy (AFM). The inner diameter of the gap junction (GJ) channels decreased in the CP of acute EAE, measured by AFM. Cell structure conformational changes showed influences the channels' flexibility in acute EAE
Allergenicity and immunogenicity of the major mugwort pollen allergen Art v 1 chemically modified by acetylation
No full textTreating allergies with modified allergens is an approach to make the treatment safer and more efficient. Art v 1 is the most prominent allergen of mugwort pollen and a significant cause of hayfever around Europe. The aim of this study was to reduce the allergenicity of Art v 1 by acetylation, and to investigate the capacity of the modified protein to generate blocking antibodies. The reduction of allergenicity of Art v 1 following acetylation was monitored by immunoblot, ELISA inhibition using a pool of sera from mugwort pollen allergic patients, basophil activation assay and by skin prick testing of mugwort-allergic patients. Rabbits were immunized against Art v 1 and acetylated Art v 1 (acArt v 1) and the rabbit antisera were tested for their capacity to block human IgE binding in ELISA. Human T cell proliferation against Art v 1 and acArt v 1 was examined in peripheral blood mononuclear cells (PBMCs) of mugwort pollen allergic patients and cytokine release in PBMC cultures was monitored. Acetylation of Art v 1 gave a derivative of reduced allergenicity in the in vitro and ex vivo tests applied. The skin test reactivity to acArt v 1 was significantly reduced in 19 patients when compared with the reactivity to Art v 1. Rabbit antibodies to acArt v 1 and Art v 1 showed similar capacity to block human IgE binding to Art v 1 in inhibition ELISA. Both proteins were able to induce proliferation of PBMCs and CD3/CD4(+) cells of mugwort-allergic patients. Release of IL-5 was significantly reduced in cultures stimulated with acArt v 1. Art v 1 modified by acetylation had a significantly reduced allergenicity in vitro and in vivo, while its immunogenicity was retained. Modification of allergens by acetylation could be a new strategy for allergen-specific immunotherapy. Cite this as: I. Perovic, M. Milovanovic, D. Stanic, L. Burazer, D. Petrovic, N. Milcic-Matic, G. Gafvelin, M. van Hage, R. Jankov and T. Cirkovic Velickovic, Clinical and Experimental Allergy, 2009 (39) 435-446
Chronic propranolol treatment affects expression of adrenoceptors on peritoneal macrophages and their ability to produce hydrogen peroxide and nitric oxide
No full textUsing both immunocytochemical and flow cytometric analyses of rat peritoneal exudate cells constitutive expression of tyrosine hydroxylase and both beta(2)- and alpha(1)-adrenoceptors on macrophages was revealed. Furthermore, according to the characteristic assemblage of tyrosine hydroxylase and adrenoceptor subtype expression different macrophage subsets were identified. In vitro treatment of macrophages with the nonselective alpha,beta-adrenoceptor agonist arterenol and/or the beta-adrenoceptor antagonist propranolol indicated that beta-adrenoceptors potentiated nitric oxide (NO) production and suggested alpha-adrenoceptor-mediated suppression of hydrogen peroxide (H2O2) production. An increase in H2O2 production in the presence of the alpha(1)-adrenoceptor antagonist ebrantil provided support for this. Chronic propranolol treatment in vivo led to increased NO and H2O2 production by peritoneal macrophages. Furthermore, this treatment resulted in opposing effects on the expression Of beta(2)- and alpha(1)-adrenoceptors on peritoneal macrophages (a stimulatory effect on beta(2)-adrenoceptors and a suppressive effect on alpha(1)-adrenoceptors). In conclusion, a subset of resident peritoneal macrophages synthesizes catecholamines, which may exert differential effects on H2O2 and NO production via distinct adrenoceptors. Finally, chronic propranolol treatment affected adrenoceptor expression on peritoneal macrophages and altered their capacity to generate NO and H2O2. (C) 2009 Elsevier B.V. All rights reserved
Public health preparedness for two mass gathering events in the context of pandemic influenza (H1N1) 2009-Serbia, July 2009
No full textPreparedness planning for two large mass gatherings events were considered in Serbia in the context of pandemic influenza (H1N1) 2009. Planning included approaches to prevention, detection and response in order to mitigate the situation at this early stage of the epidemic in Serbia. Cases of influenza A(H1N1) v were identified nationally immediately prior to the mass gatherings but also identified in association with both events, as expected in the context of the pandemic situation. This article describes the experiences of planning and the epidemiological situation during the period of the mass gathering events
Phylogenetic Analysis of Human Parvovirus B19 Sequences from Eleven Different Countries Confirms the Predominance of Genotype 1 and Suggests the Spread of Genotype 3b
Get PDFPhylogenetic analysis of 166 human parvovirus B19 sequences from 11 different countries attributed 91.57% to genotype 1, 5.42% to genotype 3b, and 3.01% to genotype 3a. Very similar viruses of genotype 1 circulated widely in Europe and Israel. Genotype 3b seems to show an increasing spread outside of Africa
Produkcija H2O2 i NO peritonealnih makrofaga pacova u odgovoru na crevne komensalne bakterije
Get PDFThe importance of commensal bacteria in the immune system development and its involvement in the etiopatogenetic mechanisms of complex multifactorial and multigenic diseases is well documented. The aim of the present study was to compare the levels of hydrogen peroxide (H2O2) and nitric oxide (NO) produced by resident peritoneal macrophages from the autoimmune disease susceptible Dark Agouti (DA) rats vs. resistant Albino Oxford (AO) rat strain, under basal conditions and subsequent to in vitro stimulation with gut commensals. Following the stimulation with phorbol myristil acetate (PMA), E. coli/PMA or P. mirabilis/PMA, AO rats macrophages have produced significantly higher levels of H2O2 compared to the cells from DA rats. Strain differences in NO production were not detected under basal conditions and after the stimulation with lipopolysaccharide and P. mirabilis. However, after the in vitro stimulation with E. coli, AO rats macrophages have produced higher levels of NO compared to DA rats macrophages. Our results demonstrated that macrophages from AO rats have higher potential to produce H2O2 and NO in response to specific commensal bacteria when compared to DA rats. A possible relationship between the macrophage activity in response to commensal bacteria and the susceptibility to induction of autoimmune/inflammatory diseases in AO and DA rat strains is suggested.Poznato je da komensalna crevna flora ima značajnu ulogu u razvoju imunskog sistema kao i u etiopatogenezi kompleksnih multifaktorijalnih i multigenetskih bolesti. Cilj ovog rada bio je da se uporedi produkcija vodonik peroksida (H2O2) i azot monoksida (NO) peritonealnih makrofaga dva inbredna soja pacova, od kojih je jedan osetljiv (Dark Agouti, DA), a drugi rezistentan (Albino Oxford, AO) na indukciju autoimunskih bolesti, kako u bazalnim uslovima tako i nakon in vitro stimulacije makrofaga sa crevnim komensalima. Nakon stimulacije sa forbol miristil acetatom (PMA), E. coli/PMA and P. mirabilis/PMA makrofage AO pacova su produkovale značajno više H2O2 u poređenju sa makrofagama DA pacova. Nisu detektovane sojne razlike u produkciji NO u bazalnim uslovima, kao ni posle stimulacije sa lipopolisaharidom i P. mirabilis. Međutim, nakon in vitro stimulacije sa E. coli makrofage AO pacova su produkovale više NO u odnosu na makrofage DA pacova. Naši rezultati su ukazali da makrofage AO pacova imaju veći potencijal za produkciju H2O2 i NO u odgovoru na specifične komensalne bakterije. Ova različita aktivnost makrofaga može biti u vezi sa različitom osetljivošću na indukciju autoimunskih/inflamatornih bolesti kod DA i AO soja pacova