Induction of anti-melanoma CTL response using DC transfected with mutated mRNA encoding full-length Melan-A/MART-1 antigen with an A27L amino acid substitution.


Journal Article

Modification of the parental immunodominant Melan-A/MART-1 peptide (MART-1(26-35)) by replacing the alanine with leucine (A27L) enhances its immunogenicity. Because of the reported advantages of RNA over peptides in DC vaccines, we sought to mutate the MART-1 gene to encode a full-length MART-1 antigen with an A27L amino acid substitution. Human DC were transfected with A27L-mutated MART-1 RNA (A27L RNA) or native MART-1 RNA, and then used to stimulate autologous T cells from a series of 8 HLA-A2+ volunteers. After three stimulations, all CTL induced with DC/A27L RNA exhibited more tetramer+ cells, and demonstrated stronger antigen-specific IFNgamma-secreting activity compared to CTL induced with DC/native RNA. A potent MART-1-specific, and predominantly class-I-restricted lysis was detected in most CTL induced with DC/A27L RNA, while native RNA-induced CTL showed minimal and non-specific lysis. HLA-A2+ DC and MART-1 negative/A2+ melanoma cells transfected with the A27L RNA were recognized and killed by MART-1-specific CTL, suggesting that these APC efficiently processed the A27L RNA and presented correct MART-1-specific epitope(s). In summary, introducing an A27L mutation into the MART-1 full-length mRNA sequence enhanced the immunogenicity of the encoded MART-1 Ag. The ease with which such a mutation can be made in RNA presents another potential advantage of using RNA for immunotherapy. Our results support considering this strategy for enhancing the immunogenicity of DC-based RNA vaccines.

Full Text

Duke Authors

Cited Authors

  • Abdel-Wahab, Z; Kalady, MF; Emani, S; Onaitis, MW; Abdel-Wahab, OI; Cisco, R; Wheless, L; Cheng, T-Y; Tyler, DS; Pruitt, SK

Published Date

  • August 2003

Published In

Volume / Issue

  • 224 / 2

Start / End Page

  • 86 - 97

PubMed ID

  • 14609574

Pubmed Central ID

  • 14609574

International Standard Serial Number (ISSN)

  • 0008-8749

Digital Object Identifier (DOI)

  • 10.1016/j.cellimm.2003.08.005


  • eng

Conference Location

  • Netherlands