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Involvement of CD4 in interleukin‐6 secretion by U937 monocytic cells stimulated with the lectin jacalin
Author(s) -
Taimi Mohammed,
Dornand Jacques,
Nicolas Michel,
Marti Jacques,
Favero Jean
Publication year - 1994
Publication title -
journal of leukocyte biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.819
H-Index - 191
eISSN - 1938-3673
pISSN - 0741-5400
DOI - 10.1002/jlb.55.2.214
Subject(s) - jacalin , biology , lectin , monocyte , secretion , u937 cell , microbiology and biotechnology , immunology , retinoic acid , cell culture , endocrinology , in vitro , biochemistry , genetics
The lectin jacalin is mitogenic for CD4 expressing T lymphocytes, interacts with the CD4 molecule, and inhibits HIV infection of CD4 + cells. In the present study the effect of jacalin was tested on cells from the monocyte/macrophage lineage that also express the CD4 molecule. We used CD4 + promyelomonocytic U937 cells differentiated towards the monocytic/macrophage lineage with either a mixture of two physiological agents, retinoic acid (RA) and 1α,25‐dihydroxyvitamin D 3 (VD), or the exogenous drug phorbol myristate acetate (PMA). The cells resulting from these treatments differed in term of CD4 expression. We focused our attention on interleukin‐6 (IL‐6) production, which implies an activation of the cells differentiated along both pathways. In CD4 + RA/VD‐treated cells, jacalin induced a 10‐fold higher IL‐6 secretion than did lipopolysaccharide (LPS). This jacalin‐induced IL‐6 production was inhibited by agents interacting with CD4 (anti‐CD4 mAbs and HIV recombinant gp120) or by recombinant soluble CD4. In contrast, the CD4 ‐ PMA‐differentiated U937 cells did not secrete any IL‐6 upon jacalin treatment, while they demonstrated a response to LPS similar to that of the RA/VD‐differentiated cells. Together with the fact that jacalin interacts with CD4, these results provide evidence of the involvement of a CD4 dependent pathway in IL‐6 production. J. Leukoc. Biol. 55: 214–220; 1994.