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| Identifier |
uch.biology.phd//2000zafiropoulos |
| Title |
In vitro μελέτη της αντιγονο-εξαρτώμενης αλλαγής ισοτύπου και επαγωγής σωματικών μεταλλαγών στο γονίδιο των ανοσοσφαιρινών σε ανθρώπινα Β λεμφοκύτταρα |
| Alternative Title |
In vitro study of the antigen-dependent induction of isotype switch and somatic mutation in the immunoglobulin gene of human B lymphocytes |
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Author
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Ζαφειρόπουλος, Αλέξανδρος
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| Abstract |
Main goal of the present study was the development of an in vitro culturing system of human B lymphocytes simulating the human thymus dependent humoral immune response. The strategy was: 1) define the culture conditions according to my theoretical model, 2) design and construct immuno-genic antigen formulations, 3) induce secretion of antibodies of desired specificity, 4) induce isotype switch, 5) induce the somatic mutation mechanism and 6) evaluate the liposomes as an antigen delivery system. The conditions of the culture system were defined based on the theory that the main event that drives the differentiation of the B cell during the immune response is its interaction with a properly activated T cell. In our system this interaction was achieved through normal antigen presentation of the B cell to the T cell. Selection of appropriate T cell epitope from tetanus toxoid enabled us to recruit the population of already existing memory T cells from potential donors. As B cell antigens were selected: 1) V3 region of gp120 of HIV-1 (LAI) representative of foreign antigens and 2) the core of MUC-1 representative of autologous antigens. The in vitro culture system succeeded in inducing specific anti-bodies against both the V3 and the autologous antigen MUC-1. It also succeeded in inducing matura-tion of the immune response through isotype switching of the resulting antibodies from IgM to IgG. In the next phase utilizing single B cell cultures we showed that the in vitro system could induce the so-matic mutation machinery and produce mutations and produce mutations in the immunoglobulin genes of the B cells. Expression in bacterial strains of the mutated antibodies showed that they were specific for the immunizing antigen proving that the induction of mutation was antigen related. Finally the study of the liposomes showed that they represent a potent alternative of the soluble antigen. The spectacular finding regarding the liposomes was that when they are covered with the V3 peptide from gp120 of HIV-1 exerts a stimulatory effect on memory T cells. Further study of the liposomes showed that the phenomenon is strictly V3 dependent and that it appears during the interaction of the antigen presenting cell and the memory T cell. These results give a new perspective in the pathology of HIV.
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| Language |
Greek |
| Issue date |
2000-09-28 |
| Collection
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School/Department--School of Sciences and Engineering--Department of Biology--Doctoral theses
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Type of Work--Doctoral theses
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| Views |
217 |
In vitro μελέτη της αντιγονο-εξαρτώμενης αλλαγής ισοτύπου και επαγωγής σωματικών μεταλλαγών στο γονίδιο των ανοσοσφαιρινών σε ανθρώπινα Β λεμφοκύτταρα
