[Theory of multistep lymphocyte transformation].
The transformation of B lymphocytes in lymph nodes proceeds from the specialized small (centrocytoid) blast cell of the lymphatic tissue germinal centre base. It runs three subsequent steps. The transformation stream of lymphocytes of the first step is derived from the basal matrix of germinal centres and is aimed towards its replica in the mantle zone. Therein the transformed cells are supplemented and qualitatively altered towards the prevailing monocytic cells of the second step. The monocytoid cells are squeezed through the mantle zone under the basal part of the germinal centres. The third step continues in the terminal medullary direction, functionally linking up to the T4 paracortical nodules. A hierarchic feedback mechanism operates between individual steps, but partial hyperplasia of one step is possible. Under adequate antigenic stimulation, effector cells of local significance are derived from the main stream of incompletely transformed cells. During the first step (germinal centres) it is the lymphoplasmacytoid cells, whereas immunocytes and autoaggressive clear cells are produced during the second (mantle zone) step. The third (medullary) step as the final one results in the development of committed blood lymphocytes and plasmacytes. Transformation depends on local structural conditions, but immediate generic relations are not always present. The theory may be useful for the understanding of hyperplastic and neoplastic conditions usually comprising mixtures of cells belonging to one transformation step.
Bednár
B
B
Hlavův ústav 1. LF UK, Praha.
D006801:Humans; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation; D008223:Lymphoma / Q000473:pathology
Teorie vícestupnové transformace lymfocytů.