Projects / Programmes
Human Monocyte Derived Dendritic Cells - The Activators and Modulators of Specific Immune Responses
Code |
Science |
Field |
Subfield |
1.09.00 |
Natural sciences and mathematics |
Pharmacy |
|
Code |
Science |
Field |
B740 |
Biomedical sciences |
Pharmacological sciences, pharmacognosy, pharmacy, toxicology |
T490 |
Technological sciences |
Biotechnology |
B500 |
Biomedical sciences |
Immunology, serology, transplantation |
monocytes; dendritic cells; immunomodulation; tumor antigens; HLA molecules; immuno-tolerance
Researchers (11)
Organisations (3)
Abstract
Dendritic cells (DC) are playing a key role in regulation and modulation of the immune system. They are extremely effective in evoking specific immune responses as well as in determining their properties, extent and duration. They are also deeply involved in maintainig the tolerance to self-antigens. Cancer and many autoimmune diseases are caused by ineffective and maintained due to inadequate immune responses, with a clear involvement of DC.
Dendritic cells, prepared from human monocytes in vitro, are potential antigen specific positive (enhancement) or negative (suppression) modulators of immune responses. These kind of effects are due to their close interactions with effector or regulatory T cells and are greately dependent on the status of their differentiation. The aim of our work will be to optimize the isolation of human monocytes from peripheral blood and to prepare mature DC in vitro by applying four different differentiation factors: bacterial lipopolysaccharide (LPS), a defined combinatination of recombinant pro-inflammatory cytokines, monocyte conditioned medium (MCM) and TNF-alpha.
We will study their differentiation profiles and their respective capabilities to evoke alloimmune responses in co-cultures of differentially matured DC and allogeneic T lymphocytes. During the differential DC maturation we will monitor the changes in expression of their molecular markers, CD83, CD80, CD86, class I and class II HLA molecules as well as the kinetics of their IL-12 production. Additionally we will also measure the extent of proliferating T cells, their cytokine production profiles and their phenotype characteristics (activators, suppressors, regulators), to assess the influence of DC on the properties and elapse of the immune response.
Our further work will be dedicated to the optimization of tumor cell (TC) isolation from tumor biopsies, providing us with a source of known as well as yet unknown tumor antigens (TA) and specific targets for effector T cells, prepared in vitro. We plan to optimize different ways of delivery of TA into DC, simultaneously taking into account the expression of specific HLA class I molecules on their surfaces: electrofusion of DC and TC, whole TC derived RNA (cell-lines, primary TC) transfected into DC and pulsing of DC with whole TC lysates or solutions of defined synthetic TA in a form of small soluble peptides. Such DC will present respective TA in the context of their own HLA molecules. Their, most probably differential effectiveness in activation and maturation of anti-tumor T cell effectors, will be studied in carefully planned allogeneic as well as autologous proliferative (MLR), cytotoxic (CTLp and CML) and binding (tetramers) in vitro functional tests.
The expected results will represent a basis for optimal preparation of DC in vitro, to be used for the purposes of clinical modulation of immune responses in cancer, treatment of autoimmune diseases and the planned onset of tolerance to disparate tissue antigens prior to tissue and organ transplantation.