Elevation of intracellular cAMP in human T lymphocytes by an anti-CD44 mAb
| Autor: | B L Rothman, N Kennure, K A Kelley, M Katz, T M Aune |
|---|---|
| Rok vydání: | 1993 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 151:6036-6042 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.151.11.6036 |
| Popis: | Regulation of lymphocyte responses to activation of the CD3/TCR complex by other cell surface proteins expressed on lymphocytes is a well established phenomenon. CD44 is an example of such a cell surface protein. Anti-CD44 mAb have been identified which either stimulate or inhibit lymphocyte function. Certain anti-CD44 mAb augment proliferation and IL-2 production by T cells stimulated through the CD2 or CD3/TCR pathways. An anti-CD44 mAb with opposing properties has also been identified. This mAb inhibits activation of human T cells by preventing the rise in [Ca2+]i stimulated by OKT3. The purpose of experiments reported here was to further characterize this phenomenon. The results show that the anti-CD44 mAb, 212.3, does not inhibit inositol phosphate turnover stimulated by OKT3 but does inhibit elevation of intracellular [Ca2+]i in these same cells. Addition of 212.3 to purified human T cells results in a rapid increase in intracellular levels of cAMP. Elevation of cAMP by 212.3 is time- and concentration-dependent. Activation of adenylate cyclase by forskolin also results in elevation of intracellular cAMP and inhibition of the increase in [Ca2+]i stimulated by OKT3. Taken together, these data suggest that CD44 may be positively coupled to adenylate cyclase and that activation of adenylate cyclase by the anti-CD44 mAb, 212.3, may mediate the inhibition of the OKT3-stimulated elevation of [Ca2+]i. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|