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: Contrasting effects of interleukin 4 (IL-4) on the in vitro proliferation of human B cells is due to the presence of B cell subsets in different activation states.
    Author: De Groot C, Braun J, Mevissen ML, Wormmeester J.
    Journal: Lymphokine Res; 1990; 9(3):321-32. PubMed ID: 2169010.
    Abstract:
    Human tonsillar B lymphocytes proliferate in vitro after activation with immobilized anti-IgM antibodies in combination with interleukin 2 (IL-2) or interleukin 4 (IL-4). In addition to its proliferative effects, IL-4 is also able to inhibit B cell proliferation. An explanation for these different actions of the same protein is not as yet available. The susceptibility to the inhibitory action of IL-4 emerges at late time points after in vitro activation of the B cells, whereas IL-4 shows its growth promoting action during early stages of culture, indicating that activated IL-2 responsive B cells are the targets for IL-4 dependent inhibition. Freshly isolated tonsillar B lymphocytes also appear to be susceptible to IL-4 dependent suppression. Isotonic Percoll gradient centrifugation, that has been used by several groups as a standard procedure to isolate high density, resting used by several groups as a standard procedure to isolate high density, resting cells from tonsil B lymphocytes, does not result in separation of B cells with different in vitro proliferative response to IL-2 and IL-4. However, partial separation of cells with "resting" and "activated" phenotypes can be achieved by centrifugation in slightly hypotonic Percoll gradients. High-density fractions contain cells with a "resting" phenotype which after in vitro activation proliferate with IL-4 but not with IL-2. "Activated" B cells accumulate in the low-density fractions as concluded from the increased expression of transferrin receptors and HLA-DR molecules on these cells. However, these cells no longer proliferate in vitro with immobilized anti-IgM antibodies, possibly due to damage caused by the hypotonic treatment during centrifugation. Our data indicate that resting B cells when activated in vitro with immobilized anti-IgM antibodies proliferate primarily with IL-4 but not with IL-2. In contrast, about 15 hours after activation the cells become responsive to IL-2. At that stage, IL-4 becomes an inhibitory factor.
    [Abstract] [Full Text] [Related] [New Search]