Browsing by Subject "Homing"

Now showing 1 - 2 of 2
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    Dendritic cell migration and lymphocyte homing imprinting
    (Murcia : F. Hernández, 2008) Villablanca, Eduardo J.; Russo, Vicenzo; Rodrigo Mora, J.
    For an effective adaptive immune response to occur, dendritic cells (DC), which are the most efficient antigen-presenting cells, must be able to sample the peripheral microenvironment and migrate towards secondary lymphoid organs (SLO) where they activate naïve lymphocytes. Upon activation, lymphocytes proliferate and acquire the capacity to migrate to extralymphoid compartments. Although the molecular mechanisms controlling lymphocyte homing to lymphoid and to some extralymphoid tissues have been described in significant detail, it is much less clear how DC migration is controlled. Do DC obey similar adhesion cues that lymphocytes do, or do they have their own “zip codes”? This is relevant from a therapeutic standpoint because effective DC-based vaccines should be able to reach the appropriate tissues in order to generate protective immune responses. Here, we discuss some of the mechanisms used by DC to reach their target tissues. Once DC arrive at their destination, they are exposed to the tissue microenvironment, which likely modulates their functional properties in a tissue-specific fashion. This local DC “education” is probably responsible among other things; for the acquisition of tissue-specific homing imprinting capacity by which DC instruct lymphocytes to migrate to specific tissues. Finally, we discuss how dysregulation of these signals may play a key role in disease.
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    Labeling of adult stem cells for in vivo-application in the human heart
    (Murcia : F. Hernández, 2005) Wiehe, J.M.I.; Zimmermann, O.; Greiner, J.; Homann, J.M.; Wiesneth, M.; Hombach, V.; Torzewski, J.
    Tissue regeneration with human hematopoietic or mesenchymal stem cells has become a fashionable research topic. In cardiology, intracoronary injection of adult stem cells has already been used for the treatment of human myocardial infarction and ischemic cardiomyopathy. The experimental background of such therapies, however, i.e. the potential of adult stem cells to regenerate myocardium through “transdifferentiation” of hematopoietic or mesenchymal stem cells into cardiomyocytes described in animal models, has recently been challenged by other experimental data. Nonetheless, clinical trials are continuing. This may be due to the fact that, in openlabeled pilot trials, a benefit of intracoronary injection of adult stem cells for the treatment of myocardial infarction has been described. As pilot trials may overemphasize the beneficial effects of intracoronary injection of bone marrow stem cells, controled doubleblinded randomised multicenter studies are warranted. Furthermore, a careful characterization of the cells involved in the proposed cardiac repair as well as in vivo-monitoring of such cells following intracoronary injection in humans might help to answer many essential questions linked to this important research topic. The latter requires biocompatible labeling. This review focusses on the technologies available for stem cell labeling and summarizes the arguments and contraarguments to use these labeling technologies for application in humans.