Lewis J J, Janetzki S, Schaed S, Panageas K S, Wang S, Williams L, Meyers M, Butterworth L, Livingston P O, Chapman P B, Houghton A N
Swim Across America Laboratory, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
Int J Cancer. 2000 Aug 1;87(3):391-8. doi: 10.1002/1097-0215(20000801)87:3<391::aid-ijc13>3.0.co;2-k.
The lack of reproducible, quantitative assays for T-cell responses has been a limitation in the development of cancer vaccines to elicit T-cell immunity. We utilized the Elispot assay, which allows a quantitative and functional assessment of T cells directed against specific peptides after only brief in vitro incubations. CD8(+) T-cell reactivity was determined with an interferon (IFN)-gamma Elispot assay detecting T cells at the single cell level that secrete IFN-gamma. We studied both healthy individuals and patients with melanoma. Healthy HLA-A0201-positive individuals showed a similar mean frequency of CD8(+) cells recognizing a tyrosinase peptide, YMDGTMSQV, when compared with melanoma patients prior to immunization. The frequencies of CD8(+) cells recognizing the tyrosinase peptide remained relatively constant over time in healthy individuals. Nine HLA-A0201-positive patients with stage IV metastatic melanoma were immunized intradermally with the tyrosinase peptide together with the immune adjuvant QS-21 in a peptide dose escalation study with 3 patients per dose group. Two patients demonstrated a significant increase in the frequency of CD8(+) cells recognizing the tyrosinase peptide during the course of immunization, from approx. 1/16,000 CD8(+) T cells to approx. 1/4,000 in the first patient and from approx. 1/14,000 to approx. 1/2,000 in the second patient. These results demonstrate that modest expansion of peptide-specific CD8(+) T cells can be generated in vivo by immunization with peptide plus QS-21 in at least a subset of patients with melanoma.
缺乏可重复的、用于T细胞反应的定量检测方法一直是开发引发T细胞免疫的癌症疫苗的一个限制因素。我们采用了酶联免疫斑点分析（Elispot分析），该方法仅需短暂的体外孵育，就能对针对特定肽段的T细胞进行定量和功能评估。通过检测在单细胞水平分泌干扰素-γ（IFN-γ）的T细胞的IFN-γ Elispot分析来确定CD8(+) T细胞反应性。我们研究了健康个体和黑色素瘤患者。与免疫前的黑色素瘤患者相比，健康的HLA-A0201阳性个体识别酪氨酸酶肽段YMDGTMSQV的CD8(+)细胞的平均频率相似。在健康个体中，识别酪氨酸酶肽段的CD8(+)细胞频率随时间保持相对恒定。在一项肽剂量递增研究中，9名HLA-A0201阳性的IV期转移性黑色素瘤患者皮内注射酪氨酸酶肽段以及免疫佐剂QS-21，每个剂量组3名患者。两名患者在免疫过程中识别酪氨酸酶肽段的CD8(+)细胞频率显著增加，第一名患者从约1/16,000个CD8(+) T细胞增加到约1/4,000个，第二名患者从约1/14,000个增加到约1/2,000个。这些结果表明，在至少一部分黑色素瘤患者中，通过肽段加QS-21免疫可在体内产生适度的肽特异性CD8(+) T细胞扩增。
