These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Quantitation of the number of mitogen molecules activating DNA synthesis in T and B lymphocytes.
    Author: Möller G, Andersson J, Pohlit H, Sjöberg O.
    Journal: Clin Exp Immunol; 1973 Jan; 13(1):89-99. PubMed ID: 4587501.
    Abstract:
    Thymus-derived (T) and bone-marrow-derived (B) lymphocytes bound equal numbers of Concanavalin A (Con A) molecules, although only T cells were stimulated to proliferation by soluble Con A. Optimal T cell proliferation occurred when approximately 3 × 106 molecules of Con A were bound per cell, which corresponds to 3–10% of the available receptors. Con A can be converted to a selective B cell mitogen provided it was presented to the cells in a locally concentrated form, achieved by cross-linking the lectin to the bottom of tissue culture Petri dishes. Optimal B cell stimulation by insolubilized Con A was obtained at a density of 1–4 × 1012 molecules/cm.2 It was estimated that per unit surface area, B and T cells were activated by the same number of Con A molecules, whereas T cells required more molecules per cell. In terms of T–B cell co-operation this suggests that optimally activated T cells present an optimally stimulating number of Con A molecules to the B cells by direct cell to cell interaction. It is postulated that the actual interaction between Con A and the sugar containing receptor at the cell membrane is not directly responsible for lymphocyte activation, but as a consequence of this initial binding, the Con A-receptor complex interacts with a second membrane receptor of a different type. When a sufficient number of these second receptors have reacted with the Con A-sugar receptor complex the cell became activated. T cells are postulated to have a greater number of the second type receptors than B cells. The ability of locally concentrated Con A to activate B cells but not T cells is explained in terms of this hypothesis.
    [Abstract] [Full Text] [Related] [New Search]