Article

Influence of low dose irradiation on differentiation, maturation and T-cell activation of human dendritic cells.

Department of Radiotherapy and Radiation Oncology, University of Leipzig, Stephanstrasse 21, 04103 Leipzig, Germany.
Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis (Impact Factor: 3.9). 03/2011; 709-710:32-9. DOI: 10.1016/j.mrfmmm.2011.02.007
Source: PubMed

ABSTRACT Ionizing irradiation could act directly on immune cells and may induce bystander effects mediated by soluble factors that are released by the irradiated cells. This is the first study analyzing both the direct effect of low dose ionizing radiation (LDIR) on the maturation and cytokine release of human dendritic cells (DCs) and the functional consequences for co-cultured T-cells. We showed that irradiation of DC-precursors in vitro does not influence surface marker expression or cytokine profile of immature DCs nor of mature DCs after LPS treatment. There was no difference of single dose irradiation versus fractionated irradiation protocols on the behavior of the mature DCs. Further, the low dose irradiation did not change the capacity of the DCs to stimulate T-cell proliferation. But the irradiation of the co-culture of DCs and T-cells revealed significantly lower proliferation of T-cells with higher doses. Summarizing the data from approx. 50 DC preparations there is no significant effect of low dose ionizing irradiation on the cytokine profile, surface marker expression and maturation of DCs in vitro although functional consequences cannot be excluded.

0 Bookmarks
 · 
102 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Inflammatory diseases are the result of complex and pathologically unbalanced multicellular interactions. For decades, low-dose X-irradiation therapy (LD-RT) has been clinically documented to exert an anti-inflammatory effect on benign diseases and chronic degenerative disorders. By contrast, experimental studies to confirm the effectiveness and to reveal underlying cellular and molecular mechanisms are still at their early stages. During the last decade, however, the modulation of a multitude of immunological processes by LD-RT has been explored in vitro and in vivo. These include leukocyte/endothelial cell adhesion, adhesion molecule and cytokine/chemokine expression, apoptosis induction, and mononuclear/polymorphonuclear cell metabolism and activity. Interestingly, these mechanisms display comparable dose dependences and dose-effect relationships with a maximum effect in the range between 0.3 and 0.7 Gy, already empirically identified to be most effective in the clinical routine. This review summarizes data and models exploring the mechanisms underlying the immunomodulatory properties of LD-RT that may serve as a prerequisite for further systematic analyses to optimize low-dose irradiation procedures in future clinical practice.
    Frontiers in Oncology 01/2012; 2:120.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic cells play an essential role in the immune system. We have previously reported that X-irradiated monocytes, precursors of dendritic cells, can differentiate into dendritic cells and then mature in terms of surface antigen expression after tumor necrosis factor-α stimulation, but show reduced functionality. Dendritic cells can mature in response to various types of maturation stimuli. Therefore, this study investigated whether dendritic cells from monocytes exposed to ionizing radiation can adequately respond to pathogen-derived components and proinflammatory cytokines. Human monocytes separated from buffy coats were exposed to X rays, and were then differentiated into immature dendritic cells. Immature dendritic cells were stimulated by lipopolysaccharide (LPS) or proinflammatory cytokine mixture. The dendritic cells from nonirradiated and X-irradiated monocytes showed maturation after LPS and proinflammatory cytokine mixture stimulation as confirmed by findings of surface antigen expression. Upon LPS stimulation, however, the expression levels of CD80 and CD83 on dendritic cells from X-irradiated monocytes were lower than those of dendritic cells from nonirradiated monocytes. Such reductions were not observed upon proinflammatory cytokine mixture stimulation. Similarly, an impairment of matrix metalloproteinase-9 and cytokine production was observed in LPS-stimulated dendritic cells from X-irradiated monocytes, whereas these impairments were not observed upon proinflammatory cytokine mixture stimulation. The ability of dendritic cells to stimulate T cells was lower in the irradiated group compared with the nonirradiated group despite the type of maturation stimulus. Thus, the present study suggests that the influence of X irradiation on the maturation of dendritic cells depends on the type of maturation stimulus used and that X irradiation impairs the response of dendritic cells to LPS.
    Radiation Research 08/2012; 178(4):280-8. · 2.70 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.
    Frontiers in Oncology 01/2012; 2:102.

Full-text

View
34 Downloads
Available from
May 21, 2014