Following allograft transplantation, the immune system is triggered to induce an immunogenic response against the non-self organ. To prevent the induction of this immunogenic response, recipients... Show moreFollowing allograft transplantation, the immune system is triggered to induce an immunogenic response against the non-self organ. To prevent the induction of this immunogenic response, recipients are treated with immunosuppressive medication. The majority of these medications target T cells, which play a key role in the rejection process, and thereby prevent acute rejection in most of the recipients. Non-specific targeting of these T cells not only prevents acute rejection, it also prevents responses against pathogens or tumor growth. In addition, long-term use of immunosuppressive agents may cause organ failure due to toxic effects on the organ [1]. Therefore, the ultimate goal is to develop a therapy, which targets alloreactive T cells, allowing a normal response against pathogens and tumors, in the absence of chronic use of immunosuppressive agents. Various strategies have been employed to induce such a donor-specific tolerance, amongst which treatment with immature DC [2]. These immature DC have, in contrast to mature DC, the capacity to induce tolerogenic responses and are therefore an attractive candidate for cellular therapy. The studies presented in this thesis demonstrate that in fully mismatched kidney transplantation models, administration of modulated donor-derived DC to recipient__s results in regulation of recipient__s immune response. Both the donor-specific hyporesponsiveness of recipient T cells and the reduced influx of CD8+ T cells into the graft of LPS-DexDC treated recipients indicate a positive effect of this treatment. However, optimization of this treatment is necessary, since no prolonged allograft survival was induced. Several mechanisms, which are not regulated by LPS-DexDC, may be responsible for the observed rejection, amongst which the preformed alloantibodies, increased levels of C3 in the graft and the increased influx of NK cells. Additional studies are required to explore the modulating effects of antibodies which block co-stimulation and/or short courses of immunosuppressive drugs as a co-treatment in these settings. Show less
Rheumatoid arthritis (RA) is a relatively common disease that is characterized by chronic inflammation of joints. The research as described in this thesis focused on the question of whether... Show moreRheumatoid arthritis (RA) is a relatively common disease that is characterized by chronic inflammation of joints. The research as described in this thesis focused on the question of whether adoptive cellular therapy is effective in a mouse model of RA. The most generally known type of adoptive cellular therapy is, probably, bone marrow transplantation (BMT), i.e. BM cells from a healthy donor are transplanted to the patient. Especially, hematological disorders like leukemia are treated with BMT; however, the research presented in this thesis strongly suggests that BMT may also effectively treat diseases, such as RA, in the (near) future. The efficacy of other types of adoptive cellular therapies was also investigated, including the transfer of regulatory T cells. Most strikingly, the disappearance of autoaggressive immune cells was associated with the efficacy of the treatment. These results suggest that these immune cells that, directly or indirectly, cause damage to the patient___s joints were eliminated and/or were kept quiescent. These studies are of importance for the future improvement of the treatment of rheumatic diseases like RA. Show less
