| 1. |
- Speiser, Daniel E, et al.
(författare)
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Ex vivo analysis of human antigen-specific CD8+ T-cell responses : quality assessment of fluorescent HLA-A2 multimer and interferon-gamma ELISPOT assays for patient immune monitoring.
- 2004
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Ingår i: Journal of immunotherapy (1997). - 1524-9557 .- 1537-4513. ; 27:4, s. 298-308
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Tidskriftsartikel (refereegranskat)abstract
- The authors developed a standardized approach for immune monitoring of antigen-specific CD8+ T cells within peripheral blood lymphocytes (PBLs) that combines direct ex vivo analysis of Melan-A/MART-1 and influenza-specific CD8+ T cells with HLA-A2/peptide multimers and interferon-gamma ELISPOT assays. Here the authors assessed the quality of results obtained with 180 PBLs from healthy donors and melanoma patients. Reproducibility of the multimer assay was good (average of 15% variation). In the absence of in vivo antigen-specific T-cell responses, physiologic fluctuations of multimer-positive T cells was low, with variation coefficients of 20% for Melan-A and 28% for influenza-specific T cells. In contrast, patients with vaccination-induced T-cell responses had significantly increased T-cell frequencies clearly exceeding physiologic fluctuations. Comparable results were obtained with ELISPOT assays. In conclusion, this approach is well suited to assess T-cell responses as biologic endpoints in clinical vaccine studies.
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| 2. |
- Zippelius, Alfred, et al.
(författare)
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Effector function of human tumor-specific CD8 T cells in melanoma lesions : a state of local functional tolerance.
- 2004
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 64:8, s. 2865-73
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Tidskriftsartikel (refereegranskat)abstract
- Although tumor-specific CD8 T-cell responses often develop in cancer patients, they rarely result in tumor eradication. We aimed at studying directly the functional efficacy of tumor-specific CD8 T cells at the site of immune attack. Tumor lesions in lymphoid and nonlymphoid tissues (metastatic lymph nodes and soft tissue/visceral metastases, respectively) were collected from stage III/IV melanoma patients and investigated for the presence and function of CD8 T cells specific for the tumor differentiation antigen Melan-A/MART-1. Comparative analysis was conducted with peripheral blood T cells. We provide evidence that in vivo-priming selects, within the available naive Melan-A/MART-1-specific CD8 T-cell repertoire, cells with high T-cell receptor avidity that can efficiently kill melanoma cells in vitro. In vivo, primed Melan-A/MART-1-specific CD8 T cells accumulate at high frequency in both lymphoid and nonlymphoid tumor lesions. Unexpectedly, however, whereas primed Melan-A/MART-1-specific CD8 T cells that circulate in the blood display robust inflammatory and cytotoxic functions, those that reside in tumor lesions (particularly in metastatic lymph nodes) are functionally tolerant. We show that both the lymph node and the tumor environments blunt T-cell effector functions and offer a rationale for the failure of tumor-specific responses to effectively counter tumor progression.
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