Contents - Medicinski Fakultet u Sarajevu - University of Sarajevo

Folia Medica 2011; 46 No 1:41-47IntroductionCytokines are low level-molecular proteinssecreted by wide spectrum of cells and includedin the mediation and the regulationof non-specific and specific acquired immuneresponse. Their function is connectionto specific receptors in the membrane oftarget cells which induce signal pathways viaother mediators, often tyrosine kinase, andleads to change in the expression of genesencode the functions and the behaviour ofcells (1). On the basis dominant biologicalactivity in the toxoplasma infection, theycan be divided into 2 main types: protectiveand regulatory cytokines (2). T. gondii infectionis strong trigger of natural immunitywith non-specific activation of macrophagesand along with other hematopoietic andnon-hematopoietic cells (3). They produceIL 12 that then activates NK and T cells tosecrete IFN-γ which early burst is crucial inshaping of resistance to this infection. IFN-γsynergizes with TNF-α in mediating to killT. gondii tachyzoites by macrophage microbicidalfunction (4). Combination of theseboth cytokines leads to production of reactivenitrogen intermediates which are capableof reducing parasite proliferation.Non-specific immune response leadsto differentiation of macrophages and Blymphocytes into APC. T lymphocytes arestimulated by APC presenting specific antigento TCR (T cell receptor) (5). This resultsin the Th1 differentiation of CD4+ TLwith production protective cytokines IFN-γand IL 2, and also Th2 differentiation withproduction regulatory cytokines IL 4, IL 5,IL 6 and IL 10. These cytokines synergeticpromote the regulation of the protectiveimmunity (6,7,8). CD8+ TLs, activated byIL 2 from Th1 type cells, show cytotoxicactivity against parasite and infected cells.Finally, the control of this infection is resultedby synergetic action between CD4+and CD 8+ TL (9). Acute phase of infectionis characterized by high levels of IFN-γ andproinflammatory cytokine, but also of synthesisof IL 10 to avoid an excessively strongcell mediated immunity and then to allowthe parasite to survive and establish chronicinfection (10). Chronic phase of infection ischaracterized by decrease of level of IFN-γand proinflammatory cytokines, while thelevel of IL 10 rises (11). Most of the datain the field of immunity of Toxoplasma infectionhave been obtained from studies inanimals, in particular, in mice. Although,the mice model represents a vast spectrumof immune response related to controlledvariation of the genetic background, in essence,these data acquired in animals cannotbe directly applied to humans. The aim ofthis research is to measure and analyze thelevel of cytokines (IFN-γ, TNF-α and IL 10).Material and methodsThis research was clinical-experimentalstudy and involved experimental and controlgroup. First group of subjects was representedby 40 patients seropositive to T.gondii, out of which 26 patients had acutetoxoplasma infection and 14 had chronictoxoplasma infection. Second group consistedof 30 subjects seronegative to T. gondii.Their serums were tested for the presenceand concentration of specific cytokines(IFN-γ, TNF-α and IL10). This survey wasconducted at Institute for Microbiology andpathology of the University Clinical CenterTuzla during 2007.The level of mentioned cytokines wasverified by the Elisa test (enzyme-linked immunosorbentassay) using commercial kits:IFN-γ-EASIA (Biosource Europe S.A, Nivelles,Belgium), Human TNF-α/TNFSF1A(R&D Systems Inc, Minneapolis, USA) andHuman IL-10 (R&D Systems Inc, Minneapolis,USA). The plates with the samples, standardsand controls were examined at 450nmin the «Metertech 960» reader during 3042