Tumor antigen-specific T cells for immune monitoring of dendritic cell-treated glioblastoma patients.

CD8(+) T cells are part of the adaptive immune system and, as such, are responsible for the elimination of tumor cells. Dendritic cells (DC) are professional antigen-presenting cells (APC) that activate CD8(+) T cells. Effector CD8(+) T cells in turn mediate the active immunotherapeutic response of DC vaccination against the aggressive glioblastoma (GBM). The lack of tumor response assays complicates the assessment of treatment success in GBM patients. A novel assay to identify specific cytotoxicity of activated T cells by APC was evaluated. Tumor antigen-pulsed DCs from HLA-A*02-positive GBM patients were cultivated to stimulate autologous cytotoxic T lymphocytes (CTL) over a 12-day culture period. To directly correlate antigen specificity and cytotoxic capacity, intracellular interferon (IFN)-γ fluorescence flow cytometry-based measurements were combined with anti-GBM tumor peptide dextramer staining. IFN-γ response was quantified by real-time polymerase chain reaction (PCR), and selected GBM genes were compared with healthy human brain cDNA by single specific primer PCR characterization. Using CTL of GBM patients stimulated with GBM lysate-pulsed DCs increased IFN-γ messenger RNA levels, and intracellular IFN-γ protein expression was positively correlated with specificity against GBM antigens. Moreover, the GBM peptide-specific CD8(+) T-cell response correlated with specific GBM gene expression. Following DC vaccination, GBM patients showed 10-fold higher tumor-specific signals compared with unvaccinated GBM patients. These data indicate that GBM tumor peptide-dextramer staining of CTL in combination with intracellular IFN-γ staining may be a useful tool to acquire information on whether a specific tumor antigen has the potential to induce an immune response in vivo.

Müller I ，Altherr D ，Eyrich M ，Flesch B ，Friedmann KS ，Ketter R ，Oertel J ，Schwarz EC ，Technau A ，Urbschat S ，Eichler H ... -  《-》

Dendritic cells cross-talk with tumour antigen-specific CD8(+) T cells, Vγ9γδT cells and Vα24NKT cells in patients with glioblastoma multiforme and in healthy donors.

The finding that dendritic cells (DCs) orchestrate innate and adaptive immune responses has stimulated research on harnessing DCs for developing more effective vaccines for DC therapy. The expression of cytomegalovirus (CMV) antigens in glioblastoma multiforme (GBM) presents a unique opportunity to target these viral proteins for tumour immunotherapy. Here, we demonstrate that Vγ9γδT cells, innate immune cells activated by zoledronate (Z) and Vα24 natural killer (Vα24NK) cells, innate/adaptive immune cells activated by α-galactosylceramide (G) can link innate and adaptive immunities through cross-talk with interferon (IFN) DCs from patients with glioblastoma multiforme (GBM) and healthy donors in a manner that can amplify the activation and proliferation of CMVpp65-specific CD8+ T cells. The IFN DCs derived from patients with GBM used in this study express lower levels of programmed cell death ligand (PD)-L1 and PD-L2 and higher levels of C-C receptor 7 (CCR7) than the most commonly used mature interleukin (IL)-4 DCs. The expression level of programmed cell death 1 (PD-1) on CD8+ T cells, including CMVpp65-specific CD8+ T cells, expanded by IFN DCs pulsed with the CMVpp65-peptide and Z plus G (IFN DCs/P+Z+G), was lower than that expanded by IFN DCs pulsed with the peptide alone (IFN DCs/P). Multi-functional T cells, including human leucocyte antigen (HLA)-A*0201-restricted CMVpp65-specific CD8+ T cells, Vγ9γδT cells and Vα24NKT cells, efficiently kill the HLA-A*0201-positive GBM cell line expressing CMVpp65 protein (T98G). These findings indicate that DC therapy using IFN DCs/P+Z+G and/or CTL therapy using CMVpp65-specific CD8+ T cells expanded by IFN DCs/P+Z+G may lead to a good clinical outcome for patients with GBM.

Eiraku Y ，Terunuma H ，Yagi M ，Deng X ，Nicol AJ ，Nieda M ... -  《-》

Vaccination with tumor lysate-pulsed dendritic cells elicits antigen-specific, cytotoxic T-cells in patients with malignant glioma.

Yu JS ，Liu G ，Ying H ，Yong WH ，Black KL ，Wheeler CJ ... -  《CANCER RESEARCH》

HER-2, gp100, and MAGE-1 are expressed in human glioblastoma and recognized by cytotoxic T cells.

Liu G ，Ying H ，Zeng G ，Wheeler CJ ，Black KL ，Yu JS ... -  《CANCER RESEARCH》

Glioblastoma patients exhibit circulating tumor-specific CD8+ T cells.

Tang J ，Flomenberg P ，Harshyne L ，Kenyon L ，Andrews DW ... -  《CLINICAL CANCER RESEARCH》