Differential Responses of Invariant Vα24JαQ T Cells and MHC Class II-Restricted CD4+ T Cells to Dexamethasone
| Autor: | Joshua D. Milner, Sally C. Kent, Timothy A. Ashley, S. Brian Wilson, Jack L. Strominger, David A. Hafler |
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| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | The Journal of Immunology. 163:2522-2529 |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.163.5.2522 |
| Popis: | NK T cells are a T cell subset in the human that express an invariant α-chain (Vα24invt T cells). Because of the well-described immunomodulation by glucocorticoids on activation-induced cell death (AICD), the effects of dexamethasone and anti-CD3 stimulation on Vα24invt T cell clones and CD4+ T cell clones were investigated. Dexamethasone significantly enhanced anti-CD3-mediated proliferation of Vα24invt T cells, whereas CD4+ T cells were inhibited. Addition of neutralizing IL-2 Ab partially abrogated dexamethasone-induced potentiation of Vα24invt T cell proliferation, indicating a role for autocrine IL-2 production in corticosteroid-mediated proliferative augmentation. Dexamethasone treatment of anti-CD3-stimulated Vα24invt T cells did not synergize with anti-Fas blockade in enhancing proliferation or preventing AICD. The Vα24invt T cell response to dexamethasone was dependent on the TCR signal strength. In the presence of dexamethasone, lower doses of anti-CD3 inhibited proliferation of Vα24invt T cells and CD4+ T cells; at higher doses of anti-CD3, which caused inhibition of CD4+ T cells, the Vα24invt T cell clones proliferated and were rescued from AICD. These results demonstrate significant differences in TCR signal strength required between Vα24invt T cells and CD4+ cells, and suggest important immunomodulatory consequences for endogenous and exogenous corticosteroids in immune responses. |
| Databáze: | OpenAIRE |
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