1. Identification of DRG-1 As a Melanoma-Associated Antigen Recognized by CD4+ Th1 Cells.
- Author
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Kiniwa, Yukiko, Li, Jiang, Wang, Mingjun, Sun, Chuang, Lee, Jeffrey E., Wang, Rong-Fu, and Wang, Helen Y.
- Subjects
CD4 antigen ,T helper cells ,IMMUNOTHERAPY ,MELANOMA treatment ,ANTINEOPLASTIC agents - Abstract
Immunotherapy has emerged as a promising strategy for the treatment of metastatic melanoma. Clinical studies have demonstrated the feasibility of cancer immunotherapy using tumor antigens recognized by CD8
+ T cells. However, the overall immune responses induced by these antigens are too weak and transient to induce tumor regression in the majority of patients who received immunization. A growing body of evidence suggests that CD4+ T helper (Th) cells play an important role in antitumor immunity. Therefore, the identification of MHC class II-restricted tumor antigens capable of stimulating CD4+ T cells may provide opportunities for developing effective cancer vaccines. To this end, we describe the identification of developmentally regulated GTP-binding protein 1 (DRG-1) as a melanoma-associated antigen recognized by HLA-DR11-restricted CD4+ Th1 cells. Epitope mapping analysis showed that the DRG1248-268 epitope of DRG-1 was required for T cell recognition. Reverse transcription-polymerase chain reaction revealed that DRG-1 was highly expressed in melanoma cell lines but not in normal tissues. DRG-1 knockdown by lentiviral-based shRNA suppressed melanoma cell proliferation and soft agar colony formation. Taken together, these data suggest that DRG-1 plays an important role in melanoma cell growth and transformation, indicating that DRG1 may represent a novel target for CD4+ T cell-mediated immunotherapy in melanoma. [ABSTRACT FROM AUTHOR]- Published
- 2015
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