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Lymphocytes play a significant role in the defense of the organism against infections and other noxious agents. These cells derive from stem cells which leave very early the marrow environment and move towards the lymph nodes, the spleen and the thymus in order to differentiate into a multitude of d...
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Διαθέσιμο Online: | http://repository.kallipos.gr/handle/11419/3084 |
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kallipos-11419-30842024-05-16T09:18:41Z Λεμφοκύτταρα Lymphocytes Λουκόπουλος, Δημήτρης Loukopoulos, Dimitris Lymphocytes play a significant role in the defense of the organism against infections and other noxious agents. These cells derive from stem cells which leave very early the marrow environment and move towards the lymph nodes, the spleen and the thymus in order to differentiate into a multitude of distinct lymphoid cell populations with precisely determined functions each. The latter are recognized through an array of immunologic markers and antigen receptors which are expressed on the cellular membranes. Main categories are the B, T and NK lymphocytes. The B lymphocytes recognize antigens against which they synthesize the respective immunoglobulins, which they then secrete in the plasma following their transformation into plasmacytes. The T lymphocytes also recognize a multitude of antigens and modify accordingly their membrane receptors; in this way, at a subsequent stage, when T lymphocytes meet other cells carrying an identifiable antigen they can readily destroy them through direct toxicity. NK cells act I an almost similar way. Antigen recognition requires antigen processing by the dendritic cells present in the marrow and the lymphoid organs and “presentation” of selected immunogenic peptides on the cellular surface along with other molecules facilitating the recognition. Complement plays a significant role in these processes. Τα λεμφοκύτταρα παίζουν σημαντικό ρόλο στην άμυνα του οργανισμού έναντι των λοιμώξεων και κάθε άλλου κινδύνου για τον οργανισμό. Παράγονται από στελεχιαία κύτταρα του μυελού των οστών που δεσμεύονται νωρίς για διαφοροποίηση προς την λεμφική σειρά και εξειδικεύονται για τις διάφορες λειτουργίες τους στο μυελό, το θύμο αδένα, τους λεμφαδένες, το σπλήνα και άλλους λεμφικούς ιστούς. Περιλαμβάνουν διάφορες κατηγορίες που αναγνωρίζονται με ειδικούς ανοσολογικούς δείκτες και υποδοχείς αντιγόνων, οι οποίοι εκφράζονται στη μεμβράνη τους. Κύριες ομάδες είναι τα Β, Τ και ΝΚ λεμφοκύτταρα. Τα Β λεμφοκύτταρα αναγνωρίζουν αντιγόνα, τα επεξεργάζονται, συνθέτουν την αντίστοιχη ανοσοσφαιρίνη και την εκκρίνουν μετά από μετατροπή τους σε πλασματοκύτταρα. Τα Τ λεμφοκύτταρα επίσης αναγνωρίζουν διάφορα αντιγόνα μέσω των υποδοχέων της μεμβράνης τους και γίνονται άμεσα κυτταροτοξικά για τα κύτταρα που εκφράζουν το αντίστοιχο για κάθε περίπτωση αντιγόνο. Παρόμοια δράση έχουν και τα κύτταρα φονείς (ΝΚ). Η αμυντική διεργασία προϋποθέτει κατεργασία και “παρουσίαση” των αντιγόνων (δενδριτικά κύτταρα) και συμμετοχή του συμπληρώματος. 2016-02-10T13:36:36Z 2021-07-08T13:08:52Z 2024-05-16T08:28:57Z 2016-02-10T13:36:36Z 2021-07-08T13:08:52Z 2024-05-16T08:28:57Z 2016-02-10 7 http://repository.kallipos.gr/handle/11419/3084 el 1 9 application/pdf |
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description |
Lymphocytes play a significant role in the defense of the organism against infections and other noxious agents. These cells derive from stem cells which leave very early the marrow environment and move towards the lymph nodes, the spleen and the thymus in order to differentiate into a multitude of distinct lymphoid cell populations with precisely determined functions each. The latter are recognized through an array of immunologic markers and antigen receptors which are expressed on the cellular membranes. Main categories are the B, T and NK lymphocytes. The B lymphocytes recognize antigens against which they synthesize the respective immunoglobulins, which they then secrete in the plasma following their transformation into plasmacytes. The T lymphocytes also recognize a multitude of antigens and modify accordingly their membrane receptors; in this way, at a subsequent stage, when T lymphocytes meet other cells carrying an identifiable antigen they can readily destroy them through direct toxicity. NK cells act I an almost similar way. Antigen recognition requires antigen processing by the dendritic cells present in the marrow and the lymphoid organs and “presentation” of selected immunogenic peptides on the cellular surface along with other molecules facilitating the recognition. Complement plays a significant role in these processes. |
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7 |
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Λουκόπουλος, Δημήτρης Loukopoulos, Dimitris |
spellingShingle |
Λουκόπουλος, Δημήτρης Loukopoulos, Dimitris Λεμφοκύτταρα |
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Λουκόπουλος, Δημήτρης Loukopoulos, Dimitris |
author_sort |
Λουκόπουλος, Δημήτρης |
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title_short |
Λεμφοκύτταρα |
title_full |
Λεμφοκύτταρα |
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Λεμφοκύτταρα |
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λεμφοκύτταρα |
publishDate |
2016 |
url |
http://repository.kallipos.gr/handle/11419/3084 |
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AT loukopoulosdēmētrēs lemphokyttara AT loukopoulosdimitris lemphokyttara AT loukopoulosdēmētrēs lymphocytes AT loukopoulosdimitris lymphocytes |
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