The alternative open reading frame of LAGE-1 gives rise to multiple promiscuous HLA-DR-restricted epitopes recognized by T-helper 1-type tumor-reactive CD4+ T cells.
The NY-ESO-1 and LAGE-1 genes are expressed by many human cancers, but not by normal tissues, with the exception of testis and placenta. The NY-ESO-1 and LAGE-1 genes give rise to multiple MHC class I and class II-presented epitopes derived from the open reading frames (ORF) 1 and 2. Here, we have investigated whether NY-ESO-1/LAGE-1 ORF2 encodes promiscuous MHC class II-restricted epitopes. Using a set of overlapping peptides from the ORF2 protein sequence and autologous dendritic cells (DCs) from normal donors and melanoma patients, we have identified three HLA-DRB1*0401-restricted peptide sequences from the LAGE-1 ORF2 that are capable of stimulating T-helper 1-type melanoma-reactive CD4+ T cells. From these bulk CD4+ T cells, we have generated CD4+ T-cell clones able to recognize not only peptide-pulsed DCs but also autologous DCs loaded with the LAGE-1 ORF2 protein. We have demonstrated that these peptides not only bind to multiple HLA-DR molecules apart from HLA-DRB1*0401 but also stimulate CD4+ T cells when presented in the context of these HLA-DR molecules. Furthermore, our binding data have delineated two additional sequences capable of broadly binding to multiple HLA-DR molecules. Altogether, these data support the immunogenicity of NY-ESO-1/LAGE-1 ORF2 gene products and clearly demonstrate their capability to stimulate T-helper 1 type CD4+ T cells. Because of the role of these cells in promoting long-lasting antitumor CTL responses, our data provide a rationale for cancer vaccine trials with peptides derived from the NY-ESO-1/LAGE-1 ORF2 for a large fraction of patients with NY-ESO-1/LAGE-1(+) tumors.
Mandic
Maja
M
Department of Medicine and Melanoma Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213, USA.
Almunia
Christine
C
Vicel
Stephanie
S
Gillet
Daniel
D
Janjic
Bratislav
B
Coval
Kara
K
Maillere
Bernard
B
Kirkwood
John M
JM
Zarour
Hassane M
HM
D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology; D000954:Antigens, Surface; D001665:Binding Sites; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D006684:HLA-DR Antigens / Q000235:genetics / Q000276:immunology*; D059811:HLA-DRB1 Chains; D006801:Humans; D008545:Melanoma / Q000235:genetics / Q000276:immunology; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000276:immunology; D011506:Proteins / Q000235:genetics* / Q000276:immunology; D018417:Th1 Cells / Q000276:immunology*
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; C104948:CTAG1B protein, human; C510162:CTAG2 protein, human; D018984:Epitopes, T-Lymphocyte; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553505:HLA-DRB1*04:01 antigen; D008565:Membrane Proteins; D011506:Proteins