Functional properties of granulocytes after thermal injury

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IMMUNOLOGY IN SERBIA

Functional properties of granulocytes after thermal injury Biljana Draskovic-Pavlovic • Dragana Vucevic • Biljana Bozic • Ivana Majstorovic • Miodrag Colic

Miodrag Colic Published online: 3 March 2012 Ó Springer Science+Business Media, LLC 2012

Abstract Thermal injury, as well as other forms of severe trauma, induces simultaneous hyper- and anti-inflammatory response. While data about decreased number and responsiveness of T lymphocytes are largely consistent, reports concerning granulocytes following trauma are contradictory. Contrary to the evidence on the increased accumulation of granulocytes in the lungs or liver, the results from our laboratory demonstrated reduced granulocyte influx in the wound that heals in conditions of thermal injury. We also demonstrated evidence that indicates impaired signal transduction in granulocytes following thermal injury, as well as their divergent response regarding the adhesiveness, oxidative burst and nitric oxide production at the wound site. Keywords

Granulocytes  Thermal injury  CD11b/CD18  Homotypic aggregation  Metabolic activity

Introduction Granulocytes are the cells that are considered to be key effectors of the inflammatory response. They are the first to arrive at the site of infection or tissue damage and trigger powerful antimicrobial mechanisms in order to eliminate pathogens or necrotic tissue. However, granulocytes generate chemotactic signals such as chemokines: monocyte chemotactic protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1a), macrophage inflammatory protein-1 beta (MIP-1b), macrophage inflammatory protein-3 alpha (MIP-3a); azurocidin and cathepsin G from

B. Draskovic-Pavlovic  D. Vucevic  I. Majstorovic  M. Colic (&) Medical Faculty of the Military Medical Academy, University of Defense in Belgrade, Crnotravska 17, 11002 Belgrade, Serbia e-mail: [email protected] B. Bozic Faculty of Biology, Institute for Physiology and Biochemistry, University of Belgrade, Belgrade, Serbia

azurophilic granules; a-defensin that attract monocytes and dendritic cells (DCs). In addition to that, granulocytederived proteases convert prochemerin to chemerin, thus attracting immature DCs and plasmacytoid DCs. There is much evidence confirming that communication between granulocytes and DCs really exists. The interaction between activated granulocytes and immature DCs is mediated by DC-specific ICAM3-grabbing non-integrin (DC-SIGN) on DCs and CD11b/CD18 on granulocytes. These two molecules do not induce the transfer of signals in DCs, but create a synapsis, which allows the transmission of TNF-a from activated granulocytes. The process in turn directs the differentiation and activation of DCs [1]. Moreover, granulocytes could induce macrophage differentiation toward pro- or anti-inflammatory state, influence B-cell differentiation and regulation of immunoglobulin (Ig) production via soluble B-lymphocyte stimulator (BlyS) or T helper polarization via IFN-c and IL-12 [2, 3]. Granulocytes are also an important source of hydrogen