Dexamethasone-induced abolition of the inflammatory response in an experimental glioma model: a flow cytometry study
| Autor: | Behnam Badie, B A Bartley, J K Preston, J Paul, J Vorpahl, J M Schartner |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Pathology
medicine.medical_specialty Lymphocyte Anti-Inflammatory Agents Dexamethasone Flow cytometry Glioma medicine Animals Cytotoxic T cell Lymphocytes Microglia medicine.diagnostic_test Brain Neoplasms business.industry Macrophages Antibodies Monoclonal Flow Cytometry medicine.disease Rats medicine.anatomical_structure Monoclonal business Ex vivo medicine.drug |
| Zdroj: | Journal of Neurosurgery. 93:634-639 |
| ISSN: | 0022-3085 |
| DOI: | 10.3171/jns.2000.93.4.0634 |
| Popis: | Object. Commonly used for management of cerebral edema in patients with brain tumors, steroid medications also have immunosuppressive functions. To characterize the effects of steroids on the central nervous system's response to tumors more clearly, flow cytometry was used to quantify the extent of inflammatory cell infiltration in an immunogenic rat glioma model.Methods. Freshly prepared 11-day-old intracranial C6 tumors that had been excised from dexamethasone-treated and untreated rats were labeled ex vivo with monoclonal antibodies against CD11b/c, CD45, and CD8a antigens. The extent of microglia (CD11b/c—highly positive, CD45—slightly positive cell), macrophage (CD11b/c—highly positive, CD45—highly positive cell), lymphocyte (CD11b/c-negative, CD45—highly positive cell), and cytotoxic T-cell (CD8a-positive cell) infiltration into each rat's tumor, tumor periphery, and contralateral tumor-free hemisphere was analyzed using flow cytometry.Microglia and lymphocytes constituted a significant component of infiltrating cells in this model, comprising 23 ± 3% and 33 ± 5% of viable cells, respectively. Macrophages, on the other hand, accounted for only 9 ± 1% of infiltrating cells. Treatment of rats with a 7-day course of low-dose dexamethasone (0.1 mg/kg/day) resulted in a greater than 50% inhibition of microglia (p = 0.03) and lymphocyte (p = 0.001) infiltration into tumors. Increasing the dexamethasone dose to 1 mg/kg/day further abolished lymphocyte infiltration (89% inhibition, p = 0.001) but had no additional inhibitory effect on microglia invasion. Macrophage infiltration of tumors was not inhibited at the dexamethasone doses used in this study (p = 0.42).Conclusions. Flow cytometry is a valuable technique for characterizing tumor-associated inflammatory cells in gliomas. Even at low doses, dexamethasone was found to inhibit significantly the infiltration of brain tumors by lymphocytes and microglia. These findings should be considered when experimental immunotherapeutic strategies are evaluated for clinical application. |
| Databáze: | OpenAIRE |
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