engleski

NK/NKT interactions in burn-induced changes of cell mediated immunity

Introduction: Natural killer T (NKT) cells are the specific type of lymphocyte subpopulations, which co-express the invariant T cell receptor and markers of NK cells lineage and have become a major focus in the studies of the innate immune response to tumors, infectious and autoimmune diseases, but the precise immunological function of these "primitive" T lymphocytes is still not well defined. Furthermore, depending on the stimulus they produce various immunomodulatory cytokines, affecting the immunologic tolerance and TH1/TH2 immune balance. Tolerance is a mechanism that may prevent or suppress potentially injurious immune responses. Natural killer T (NKT) lymphocytes can induce pro-inflammatory or anti-inflammatory immune responses and may affect on hard life-threatening opportunistic infections which are very often following burn injuries. The aim of this study was to determine the effects of burn injuries on expression of NK, NKT cells and other lymphocyte subsets in peripheral blood. Methods: Human peripheral blood mononuclear cells (PBMNC) from healthy adult volunteers and from patients with severe burn injuries were taken and labelled with antibodies by surface staining. CD3(+) /CD16+56(+) NKT cells, T cells, NK cells, CD4(+), CD8(+), CD3(+)/CD4(+), CD3(+)/CD8(+), CD5(+), CD19(+) and CD5(+)/19(+) cells of patients with burn injuries and normal controls were analyzed by flow cytometric analysis. Results:The data indicate that the percentage of CD19, double staining CD3/CD4, CD3/CD8 and CD5/CD19 positive cells are significantly decreased in peripheral blood of burned patients, while the percentage of NKT cells has shown significant augmentation. During the therapy diminished value were slowly normalizing, while the average of NKT cells were higher, indicating the role of these “ primitive” lymphocytes in control of innate immunity. Conclusion: The immunoregulatory functions of NKT cells in burn injuries are marked and we are able to discuss NKT cell based immunotherapeutic strategies. Acknowledgment: This work was supported by grant from the Croatian Ministry of Science (project 0620096-0094)

burn injuries; cellular immunity; immunodepression; NK cells; NKT cells

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