There has been an explosion in CTA-based research since CTAs were first identified in 1991 and MAGE-1 was shown to elicit an autologous cytotoxic T-lymphocyte (CTL) response in a patient with melanoma.
Among MAGE (melanoma antigen) family genes, MAGE-A (A1-8), MAGE-B (B1-3), MAGE-D1, MAGE-E1, MAGE-G1 (necdin-like 2) and MAGE-H1 were expressed in the Vn19 cells, in which neither necdin nor MAGEL2 was detectable.
Clinical grade DC from melanoma patients were generated from blood monocytes and infected with a recombinant ALVAC virus encoding either a marker gene (EGFP) or the MAGE-1-MAGE-3 minigenes.
Although MAGE-1 expression has been considered as a target for immunomodulation therapy, our findings do not indicate consistent expression of this epitope in a majority of melanomas.
Subsequently, we chose four sets of primers for the melanoma-associated antigens MAGE1, tyrosinase, Melan A/MART-1 and gp100/Pmel17 and performed PCR analysis over a range of cycle numbers.
Using several different preexisting tumor models that make use of B16F10 melanoma cells expressing a target tumor antigen (human melanoma-associated gene [MAGE]-1), we found that vaccination with bone marrow-derived DCs engineered to express MAGE-1 via adenoviral-mediated gene transfer led to a dramatic decrease in the number of metastases in a lung metastasis model, and led to prolonged survival and some long-term cures in a subcutaneous preexisting tumor model.
Knowledge of these mechanisms led to the design of a non-natural, minimally modified analogue of MAGE-1.A1, [Aib2, NMe-Ser8]MAGE-1.A1, which was highly peptidase-resistant and bound to MHC and activated MAGE-1.A1-specific anti-melanoma CTLs.
Transcription of the MAGE-1 gene and the methylation status of its Ets binding promoter elements: a quantitative analysis in melanoma cell lines using a real-time polymerase chain reaction technique.
To identify new CT antigens, we constructed an expression cDNA library from a melanoma cell line that expresses a wide range of CT antigens and screened the library with an allogeneic melanoma patient serum known to contain antibodies against two CT antigens, MAGE-1 and NY-ESO-1. cDNA clones isolated from this library identified four CT antigen genes: MAGE-4a, NY-ESO-1, LAGE-1, and CT7.
Incubation of transduced HLA-A1 expressing melanoma cell lines with 2 anti-MAGE-1.A1 CTL clones resulted in specific recognition and lysis of target cells, indicating that the exogenous MAGE-1 protein was processed and presented in a normal manner.
Immunohistology is thus a rapid and well-established method that might be used to select and monitor HLA-A1 positive patients with malignant melanoma and other candidate tumours for MAGE-1-directed immuno-therapy.
The MAGE-1 and MAGE-3 genes are expressed in tumors of different histotypes but not in normal adult tissues (with the exception of testis), while the MART-1 gene appears to be selectively expressed in melanoma.
PCR-based analysis of the freshly harvested tumor from patient PM2-B2 revealed the presence of message for the melanoma-associated gene products MAGE-1 and MAGE-3, but not for tyrosinase or MART-1/MELAN-A.
5-Aza-2'-deoxycytidine (DAC), a demethylating agent, was capable of inducing MAGE-1 expression by a MAGE-1-negative melanoma cell line 888-mel as well as by a number of other melanoma cell lines.
We have produced a MAGE-1-specific CTL line derived from the tumor-infiltrating lymphocytes (TIL) of a melanoma patient by weekly restimulation with autologous EBV-B cells pulsed with the synthetic HLA-A1-restricted MAGE-1 epitope nonapeptide EADPTGHSY.
Serological typing of normal and tumor cell lysates was in full agreement with mRNA analysis, showing expression of MAGE-1 protein in MAGE-1 mRNA-positive testis and a subset of melanomas but not in MAGE-1 mRNA-negative normal or tumor tissues.
MAGE-1 is not likely to be the common melanoma antigen recognized by the other HLA-A1- or HLA-A2-restricted cytotoxic T-lymphocytes examined in this study, but the fact that it is expressed in about 50% of melanoma cell lines makes it a reasonable target for the immunotherapy of patients bearing HLA-A1.