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

Zeinab Abdel-Wahab, Matthew F. Kalady, Sirisha Emani, Mark W. Onaitis, Omar I. Abdel-Wahab, Robin Cisco, Lee Wheless, Tsung Yen Cheng, Douglas S. Tyler, Scott K. Pruitt

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17 Scopus citations

Abstract

Modification of the parental immunodominant Melan-A/MART-1 peptide (MART-126-35) 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 IFNγ-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.

Original languageEnglish (US)
Pages (from-to)86-97
Number of pages12
JournalCellular Immunology
Volume224
Issue number2
DOIs
StatePublished - Jan 1 2003

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Keywords

  • A27L-mutated RNA
  • CTL
  • DC
  • Melan-A MART-1
  • Melanoma

ASJC Scopus subject areas

  • Immunology

Cite this

Abdel-Wahab, Z., Kalady, M. F., Emani, S., Onaitis, M. W., Abdel-Wahab, O. I., Cisco, R., Wheless, L., Cheng, T. Y., Tyler, D. S., & Pruitt, S. K. (2003). 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. Cellular Immunology, 224(2), 86-97. https://doi.org/10.1016/j.cellimm.2003.08.005