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. 1994 Jan;81(1):111-4.

Similar CD40 ligand expression on EL-4 thymoma cell lines with widely different helper activity for B lymphocytes

C Werner-Favre  1 , J F Gauchat, G Mazzei, J P Aubry, J Y Bonnefoy, R H Zubler
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Similar CD40 ligand expression on EL-4 thymoma cell lines with widely different helper activity for B lymphocytes

C Werner-Favre et al. Immunology. 1994 Jan.

Abstract

A mutagenized subclone of the murine EL-4 thymoma (clone B5) is approximately 30 times more potent than parental EL-4 cells in stimulating proliferation and Ig secretion of murine or human B cells by direct cell contact in the presence of appropriate cytokines. In this study we found that CD40 ligand (CD40L) expression was constitutive and very similar on EL-4 B5 and parental EL-4 cells according to Northern blot and flow cytometry. Activation with phorbol 12-myristate 13-acetate (PMA) alone, PMA and ionomycin, interleukin-1 (IL-1) or human T-cell supernatant did not lead to significant CD40L up-regulation. A receptor-binding assay with soluble CD40 did not reveal different ligand affinities. However, murine and human soluble CD40-IgFc fusion proteins inhibited human B-cell stimulation by EL-4 B5 cells in the presence of human T-cell supernatant. Inhibition was 96% when soluble CD40 was added on day 0 of culture and progressively decreased when the CD40 was added subsequently. Ig secretion by cytoplasmic Ig-positive cells was no longer inhibited. These findings imply that, although CD40 ligand is necessary for B-cell activation by EL-4B5 cells, additional molecule(s) must be responsible for the increased helper activity of the EL-4 B5 clone.

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References

    1. Science. 1991 Jan 4;251(4989):70-2 - PubMed
    1. Nature. 1992 May 7;357(6373):80-2 - PubMed
    1. Nature. 1992 Jul 2;358(6381):26 - PubMed
    1. J Immunol. 1992 Jul 15;149(2):655-60 - PubMed
    1. Eur J Immunol. 1992 Oct;22(10):2573-8 - PubMed

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