The expression of plasmalemma transcobalamin-Ii receptors on human blood lymphocytes stimulated by mitogens
Oreshkin, A.E.; Gudkova, M.V.; Miasishcheva, N.V.
Biulleten' Eksperimental'noi Biologii i Meditsiny 114(8): 185-187
1992
ISSN/ISBN: 0365-9615 PMID: 1334729 Document Number: 400034
The influence of mitogens on the expression of surface membrane TC-II receptors of human blood lymphocytes and internalization of (TS-II+57Co-CNCbl) complex into cytoplasm were investigated. Mature lymphocytes have a very small number of surface receptors to plasma TC-II but their expression is increased significantly by PHA or Con-A stimulation. CBl transport to cytoplasma is activated in definite sequence by two different mechanisms. Stimulated cells take free CBl without participation of TC-II in early hours of mitogen action (12-42 hrs) before maximal 3H-thymidine incorporation into DNA. On day 3 of cultivation, specific mechanism of CBl transport triggers and the number of lymphoblast receptors is increased manifold. Radioactive CBl enters cytoplasma due to interaction of TC-II-CN [57Co] CBl of the medium with surface membrane receptor of the cells. Thus, the definition of TC-II receptors as an important functional parameter may serve a marker of proliferating cells.