Melan-A/MART-1 (26-35) peptide analog (ELAGIGILTV) – Melanoma-Associated Antigen
Native Melan-A (26-35) decapeptide derives from the melanocyte lineage-specific protein Melan-A/MART-1, which is expressed in almost 75-100% of primary and metastatic melanomas.
The region 26-35 of Melan-A protein acts as an antigenic peptide that is recognized by CD8+ tumor-reactive cytolytic T lymphocytes (CTLs) for designing antigen-specific cancer vaccines. It has been shown that CD8+ Melan-A-specific CTLs isolated from melanoma patients efficiently lyse the Melan-A-expressing HLA-A*0201+ melanoma cell line. However, CTLs preferentially recognize the Melan-A (26-35) peptide as compared with the Melan-A (27-35) peptide. Moreover, the Melan-A (26-35) A27L analog (ELAGIGILTV) has a higher binding affinity to HLA-A*0201 than the native Melan-A (26-35) peptide (EAAGIGILTV), and consequently displays more potent antigenicity and immunogenicity.
It has been reported that the concentration of Melan-A (26-35) A27L analog required to obtain 50% of maximal antigenic activity (EC50) is 0.01nM, whereas that of the native Melan-A (26-35) peptide is 0.25nM. Therefore, the relative activity of Melan-A (26-35) A27L analog is 25 fold higher than that of the native Melan-A (26-35) peptide.
Furthermore, functional competition assay has shown that the concentration of Melan-A (26-35) A27L analog required to achieve 50% inhibition (IC50) of tumor lysis is 2nM, which is 10 fold lower than that of the native Melan-A (26-35) peptide. Regarding peptide stability in human serum, the half-lifes (t1/2) of the native Melan-A (26-35) peptide and the A27L analog are quite similar (45 and 40min, respectively) as measured by HPLC-ESI-MS, but much higher than that of the Melan-A (27-35) nonapeptide (5min).
SB-PEPTIDE offers the native version of Melan-A/MART-1 (26-35) peptide, as well as its scrambled version (see sections « Melan-A/MART-1 (26-35) peptide » & « Melan-A/MART-1 (26-35) scrambled »).
|Sequence : ELAGIGILTV|
|MW : 985.3 g/mol (C45H80N10O14)|
|Purity : > 95%|
|Counter-Ion : TFA Salts (see option TFA removal)|
|Delivery format : Freeze dried in propylene 2mL microtubes|
|Peptide Solubility Guideline|
|Bulk peptide quantities available|
|Product catalog||Size||Price € HT||Price $ USD|
J Clin Invest. 2005 Mar;115(3):739-746. https://doi.org/10.1172/JCI23373
Rapid and strong human CD8+ T cell responses to vaccination with peptide, IFA, and CpG oligodeoxynucleotide 7909
The induction of potent CD8+ T cell responses by vaccines to fight microbes or tumors remains a major challenge, as many candidates for human vaccines have proved to be poorly immunogenic. Deoxycytidyl-deoxyguanosin oligodeoxynucleotides (CpG ODNs) trigger Toll-like receptor 9, resulting in dendritic cell maturation that can enhance immunogenicity of peptide-based vaccines in mice. We tested whether a synthetic ODN, CpG 7909, could improve human tumor antigen–specific CD8+ T cell responses. Eight HLA-A2+ melanoma patients received 4 monthly vaccinations of low-dose CpG 7909 mixed with melanoma antigen A (Melan-A; identical to MART-1) analog peptide and incomplete Freund’s adjuvant. All patients exhibited rapid and strong antigen-specific T cell responses: the frequency of Melan-A–specific T cells reached over 3% of circulating CD8+ T cells. This was one order of magnitude higher than the frequency seen in 8 control patients treated similarly but without CpG and 1–3 orders of magnitude higher than that seen in previous studies with synthetic vaccines. The enhanced T cell populations consisted primarily of effector memory cells, which in part secreted IFN-γ and expressed granzyme B and perforin ex vivo. In vitro, T cell clones recognized and killed melanoma cells in an antigen-specific manner. Thus, CpG 7909 is an efficient vaccine adjuvant that promotes strong antigen-specific CD8+ T cell responses in humans.
J Immunol. 2001 Nov 15;167(10):5852-61. doi: 10.4049/jimmunol.167.10.5852
A new generation of Melan-A/MART-1 peptides that fulfill both increased immunogenicity and high resistance to biodegradation: implication for molecular anti-melanoma immunotherapy
Intense efforts of research are made for developing antitumor vaccines that stimulate T cell-mediated immunity. Tumor cells specifically express at their surfaces antigenic peptides presented by MHC class I and recognized by CTL. Tumor antigenic peptides hold promise for the development of novel cancer immunotherapies. However, peptide-based vaccines face two major limitations: the weak immunogenicity of tumor Ags and their low metabolic stability in biological fluids. These two hurdles, for which separate solutions exist, must, however, be solved simultaneously for developing improved vaccines. Unfortunately, attempts made to combine increased immunogenicity and stability of tumor Ags have failed until now. Here we report the successful design of synthetic derivatives of the human tumor Ag Melan-A/MART-1 that combine for the first time both higher immunogenicity and high peptidase resistance. A series of 36 nonnatural peptide derivatives was rationally designed on the basis of knowledge of the mechanism of degradation of Melan-A peptides in human serum and synthesized. Eight of them were efficiently protected against proteolysis and retained the antigenic properties of the parental peptide. Three of the eight analogs were twice as potent as the parental peptide in stimulating in vitro Melan-specific CTL responses in PBMC from normal donors. We isolated these CTL by tetramer-guided cell sorting and expanded them in vitro. The resulting CTL efficiently lysed tumor cells expressing Melan-A Ag. These Melan-A/MART-1 Ag derivatives should be considered as a new generation of potential immunogens in the development of molecular anti-melanoma vaccines.
J Immunol. 1998 Feb 15;160(4):1750–1758. doi: https://doi.org/10.4049/jimmunol.160.4.1750
Enhanced Generation of Specific Tumor-Reactive CTL In Vitro by Selected Melan-A/MART-1 Immunodominant Peptide Analogues
The Melan-A/MART-1 gene, which is expressed by normal melanocytes as well as by most fresh melanoma samples and melanoma cell lines, codes for Ags recognized by tumor-reactive CTL. HLA-A*0201-restricted Melan-A-specific CTL recognize primarily the Melan-A27-35 (AAGIGILTV) and the Melan-A26-35 (EAAGIGILTV) peptides. The sequences of these two peptides are not necessarily optimal as far as binding to HLA-A*0201 is concerned, since both lack one of the dominant anchor amino acid residues (leucine or methionine) at position 2. In this study we introduced single amino acid substitutions in either one of the two natural peptide sequences with the aim of improving peptide binding to HLA-A*0201 and/or recognition by specific CTL. Surprisingly, analogues of the Melan-A27-35 peptide, which bound more efficiently than the natural nonapeptide to HLA-A*0201, were poorly recognized by tumor-reactive CTL. In contrast, among the Melan-A26-35 peptide analogues tested, the peptide ELAGIGILTV was not only able to display stable binding to HLA-A2.1 but was also recognized more efficiently than the natural peptide by two short-term cultured tumor-infiltrated lymph node cell cultures as well as by five of five tumor-reactive CTL clones. Moreover, in vitro generation of tumor-reactive CTL by stimulation of PBMC from HLA-A*0201 melanoma patients with this particular peptide analogue was much more efficient than that observed with either one of the two natural peptides. These results suggest that the Melan-A26-35 peptide analogue ELAGIGILTV may be more immunogenic than the natural peptides in HLA-A*0201 melanoma patients and should thus be considered as a candidate for future peptide-based vaccine trials.