Dengjel Jörn, Nastke Maria-Dorothea, Gouttefangeas Cécile, Gitsioudis Gitsios, Schoor Oliver, Altenberend Florian, Müller Margret, Krämer Björn, Missiou Anna, Sauter Martina, Hennenlotter Jörg, Wernet Dorothee, Stenzl Arnulf, Rammensee Hans-Georg, Klingel Karin, Stevanović Stefan
Immatics Biotechnologies GmbH, University of Tübingen, Germany.
Clin Cancer Res. 2006 Jul 15;12(14 Pt 1):4163-70. doi: 10.1158/1078-0432.CCR-05-2470.
To elicit a long-lasting antitumor immune response, CD8+ and CD4+ T cells should be activated. We attempted to isolate HLA-DR-presented peptides directly from dissected solid tumors, in particular from renal cell carcinoma, to identify MHC class II ligands from tumor-associated antigens (TAA) for their use in peptide-based immunotherapy.
Tumor specimens were analyzed by immunohistochemical staining for their HLA class II expression. HLA class II peptides were subsequently isolated and identified by mass spectrometry. Gene expression analysis was done to detect genes overexpressed in tumor tissue. Peptides from identified TAAs were used to induce peptide-specific CD4+ T-cell responses in healthy donors and in tumor patients.
In the absence of inflammation, expression of MHC class II molecules is mainly restricted to cells of the immune system. To our surprise, we were able to isolate and characterize hundreds of class II peptides directly from primary dissected solid tumors, especially from renal cell carcinomas, and from colorectal carcinomas and transitional cell carcinomas. Infiltrating leukocytes expressed MHC class II molecules and tumor cells, very likely under the influence of IFNgamma. Our list of identified peptides contains ligands from several TAAs, including insulin-like growth factor binding protein 3 and matrix metalloproteinase 7. The latter bound promiscuously to HLA-DR molecules and were able to elicit CD4+ T-cell responses.
Thus, our direct approach will rapidly expand the limited number of T-helper epitopes from TAAs for their use in clinical vaccination protocols.
为引发持久的抗肿瘤免疫反应，应激活CD8+和CD4+ T细胞。我们试图直接从切除的实体瘤中，特别是从肾细胞癌中分离出由HLA-DR呈递的肽段，以鉴定肿瘤相关抗原（TAA）的MHC II类配体，用于基于肽段的免疫治疗。
通过免疫组织化学染色分析肿瘤标本的HLA II类表达。随后通过质谱法分离并鉴定HLA II类肽段。进行基因表达分析以检测在肿瘤组织中过表达的基因。来自已鉴定TAA的肽段用于在健康供体和肿瘤患者中诱导肽段特异性CD4+ T细胞反应。
在无炎症的情况下，MHC II类分子的表达主要局限于免疫系统细胞。令我们惊讶的是，我们能够直接从切除的原发性实体瘤中，特别是从肾细胞癌、结直肠癌和移行细胞癌中分离并鉴定出数百种II类肽段。浸润的白细胞表达MHC II类分子，肿瘤细胞很可能在γ干扰素的影响下也表达。我们鉴定出的肽段列表包含来自几种TAA的配体，包括胰岛素样生长因子结合蛋白3和基质金属蛋白酶7。后者可与HLA-DR分子广泛结合，并能够引发CD4+ T细胞反应。
因此，我们的直接方法将迅速扩充来自TAA的数量有限的辅助性T细胞表位，用于临床疫苗接种方案。
