LACK OF B7 EXPRESSION, NOT HUMAN LEUKOCYTE ANTIGEN EXPRESSION, FACILITATES IMMUNE EVASION BY HUMAN MALIGNANT GLIOMAS

摘要: OBJECTIVE: Lack of human leukocyte antigens and costimulatory molecules have been suggested as mechanisms by which malignant gliomas avoid immune recognition elimination. METHODS: Using quantitative multiparameter flow cytometric analysis, tumor cells from patients with glioblastoma multiforme (n = 18) were examined ex vivo for the expression antigen Class I II B7-1 B7-2. They compared reactive astrocytes peritumoral brain metastases 7), removed during nontumor surgery 5). RESULTS: In contrast to vast majority solid peripheral tumors, these results demonstrate that frequently express both molecules. Like most few or no B7 Functional assays using heterogeneous preparations pure populations microglia obtained fluorescence-activated cell sorting indicate CD4 + T-cells are activated only in presence exogenous costimulation (provided addition soluble agonist anti-CD28 monoclonal antibody). CONCLUSION: Thus, many failure present is not a likely impediment immunotherapeutic strategies against gliomas. Rather, need overcome low levels costimulation.