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The role of T regulatory cells in kidney transplantation
Urbanová, Anna ; Stříž, Ilja (advisor) ; Zajícová, Alena (referee)
T regulatory lymphocytes (Treg) belong to the CD4+ cell group. They are an essential part of the immunity system. Treg cells prevent from excessive activation of effector T cells and they keep the tolerance to the tissues of the body. They have high expression of CD25 and the transcription factor Foxp3. We distinguish two basic populations of Treg cells: natural Treg cells (nTreg) created in the thym and representing 5-10 % of all CD4+ cells, and induced Treg cells (iTreg), created from naive CD4+ cells in the periphery.Their regulatory effect is well-known, therefore using of Treg cells could bring about a huge treatment potential for patients with a transplantated kidney. Healthy people and patients tolerant to the transplantated kidney show higher occurance of circulating Treg cells and the Treg cells present in the graft unlike patients with chronical rejection. The tolerance is cancelled with the damage of CD4+ CD25+ cells.For a graft acceptance it is necessary to treat the patient after the transplantation with immunosuppressive medicaments resulting in suppression of immunity reaction against the graft. Their disadvantages are side effects often resulting in the patient's death. Moreover they often have a negative impact on survival and expansion of Treg cells. The analysis of flow cytometry has...
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Comparison of Immune System of Newborns and Adults
Dusilová, Adéla ; Zajícová, Alena (referee) ; Hrdý, Jiří (advisor)
In general, it is possible to characterize neonatal immune system (IS) as immature in comparison to adult IS. From a clinical point of view, newborns show an increased susceptibility to infections. Breastfeeding can contribute to the descent incidence of illnesses, because it supplies the intestinal mucosal system with antibodies of the mother`s origin, important nutrients and other immunoregulatory components. Breast milk compensates decreased newborn's capacity to produce immunoglobulins- especially IgA, that concentration reaches adult levels in two years, but even later (to the pubescent period). Other classes of antibodies are found in cord blood only sporadically except IgG, which is transferred transplacentary. Reduced ability of B lymphocytes to produce antibodies is caused by insufficient expression of surface costimulatory signals of Th2 cells. T lymphocytes are not able to react properly to low doses of stimulators (polyclonal activators - phytoid lectins: ConA or PHA), which bind to T cell receptors in complex with CD3 and proliferate in a response to anti-CD3 monoclonal antibodies. Most of the cord blood T lymphocytes display "naive" phenotype CD45RA. During intrauterine development, neonatal IS is in contact with mother IS and because a pro-inflammatory Th1 response could lead to...
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