| Autor: |
Fan, Sao-Tah, Brian, Adrienne A., Lollo, Bridget A., Mackman, Nigel, Shen, Nancy L., Edgington, Thomas S. |
| Zdroj: |
Cellular Immunology; April 15, 1993, Vol. 148 Issue: 1 p48-59, 12p |
| Abstrakt: |
To study the signaling role or CD11a/CD18 in the early events of T cell activation we have examined the induction of transcription of two important cytokines, namely TNFα and IL-2. Human peripheral blood T cells were stimulated with PMA/ionophore or immobilized anti-CD3 mAb (OKT3) with or without CD11a/CD18 engagement. Induced cytokine production by immobilized OKT3 was enhanced (3- to 10-fold) in cells adhering to OKT3 and ICAM-1 coimmobilized surfaces and anti-CD11a mAb abolished this enhancement effect. Similarly, inhibition of the PMA/ionophore-induced CD11a/CD18-mediated homotypic aggregations of T cells by mAbs specific for either CD11a or ICAM-1 reduced the induced cytokine production by more than 70%. We have also observed that greatly enhanced cytokine production resulted from cellular interactions between activated T cells and monolayers of endothelial cells. This enhancement was inhibited by a combination of CD11a-, CD18-, and ICAM-1-specific mAbs implicating a role of CD11a/CD18 in leukocyte adhesion to endothelium and diapedesis as part of the inflammatory process. By Northern analyses induced TNFα mRNA expression was significantly enhanced by the engagement of CD11a/CD18 in all the conditions mentioned above. These results, together with our previous studies on monocytes, lead to the conclusion that engagement of the CD11/CD18 family of receptor results in the transduction of cellular signals that quantitatively enhance the expression of important leukocyte-mediated immune and inflammatory responses. Copyright 1993, 1999 Academic Press |
| Databáze: |
Supplemental Index |
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