| Autor: |
Wiegers GJ; Section of Neuroimmunoendocrinology, Max Planck Institute of Psychiatry, Munich, Germany., Stec IE, Klinkert WE, Reul JM |
| Jazyk: |
angličtina |
| Zdroj: |
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2000 Jun 15; Vol. 164 (12), pp. 6213-20. |
| DOI: |
10.4049/jimmunol.164.12.6213 |
| Abstrakt: |
CD4 serves as a coreceptor during Ag recognition by the TCR. This interaction results in a marked increase in the sensitivity of a T cell to Ag presented by MHC class II molecules. Here we report that activation of T cells either by plate-bound mAb (anti-TCR, anti-CD3) or soluble activators (staphylococcal enterotoxin A, Con A) is associated with an (up to 3-fold) increase in CD4 cell surface expression on CD25+ cells, which was maximal after 72-96 h. Incubation with the glucocorticoid hormone corticosterone (CORT) shifted the enhancement of CD4 expression to a point about 24 h earlier than that observed in control cultures. In parallel, the proliferative response of these CORT-treated cells was profoundly enhanced. An involvement of increased CD4 expression in this enhanced proliferative response was evidenced by the observation that T cell proliferation in CORT-treated cultures was much less sensitive to inhibition by an inhibitory, nondepleting anti-CD4 mAb than that in control cultures. TCR down-regulation was, however, not affected by CORT. Thus, based on this study and previous reports we propose that both TCR-mediated signals and glucocorticoids are important physiological regulators of CD4 expression. In addition, these findings may be of significance for the sensitivity of CD4+ cells to HIV infection upon T cell activation, as the efficacy of primary patient HIV entry depends on the level of surface CD4. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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