Induction of antigen-specific cytolytic T cells in situ in human melanoma by immunization with synthetic peptide-pulsed autologous antigen presenting cells.

Abstract

Human melanoma cells can process the The discoveries of genes encoding a number of human melanoma-associated antigens (1-6) and of sequences of antigenic peptides serving as the cytolytic T-lymphocyte (CTL) epitopes on the appropriate major histocompatibility complex (MHC)class I molecules (7-11) have raised considerable interest in peptide-based specific melanoma vaccines. All the CTLdetermined melanoma-associated peptide epitopes that have so far been described are, however, "self' peptides (i.e., without any alteration in the sequence in the encoding gene found in the autologous normal cells). The question of whether these self peptide epitopes are immunogenic in humans has, therefore, become a crucial issue. To test the immunogenic potential of a peptide-based melanoma vaccine in vivo, we have taken an approach based on the physiologic principles underlying peptide presentation to T cells. This approach involves presenting a relevant CTL-determined peptide on the appropriate MHC-restricting elements of autologous professional antigen presenting cells (APCs). We chose to study the immunogenicity of the MAGE-1 nonapeptide EADPTGHSY (7) in vivo, since the MAGE-1 gene is not expressed in any normal tissues with the exception of certain cells in the testis (1).We have observed that a population of APCs, obtained by culturing autologous blood-derived monocyte/macrophages in granulocyte-macrophage colony-stimulating factor (GM-CSF), exhibit many of the essential features of authentic APCs (high levels of MHC class I and class II molecules, CD11b antigen, CD54 antigen, B7 molecules, and dendritic morphology expressed by a proportion of the cells). They are also capable of simultaneously providing an additional stimulatory signal(s) toward T-cell activation-analogous to some form of costimulatory, or just another stimulatory, second signal.These cultured APCs can efficiently present the MAGE-1 nonapeptide to the MAGE-1 antigen-specific CTLs (12). More importantly, they seem to be capable of overriding the negative influence of melanoma cells while activating autologous T cells in vitro (12). Based on these findings, this study was designed to examine whether the cultured APCs, pulsed with the synthetic peptide EADPTGHSY, could recruit a MAGE-1-specific CTL response in vivo at the immunization sites and at distant sites of melanoma deposits in patients with advanced stage IV melanoma, who are HLA-A1+, and whose tumor cells express the MAGE-1 gene.MATERIALS AND METHODS Patients. Patients with advanced metastatic melanoma were studied with informed consent.Cell Lines. The melanoma cell lines RM-M (HLA-A1, -3; B8, -44) and HS-M (HLA-A1, -28; B14, -57) were established from explants of metastatic melanoma in our laboratory from the two study cases according to procedures described earlier.The melanoma cell line MZ 3.1 (MAGE-1+/HLA-A1+) and the MAGE-1-/HLA-A1+ variant melanoma line MZ 2.2 and the MAGE-1 antigen-specific CTL line MZ 82/30 were gifts of Thierry Boon (Ludwig Institute, Brussels).APCs. Autologous perip...

Expression of multiple cancer-testis antigen genes in gastrointestinal and breast carcinomas

“…Some of these antigens are expressed in various tumours of different histological origins, but not in normal tissues other than testis. Therefore, these antigens have been designated cancer-testis antigens (CTAs) and their characteristics make them promising candidates for cancer-specific immunotherapy; clinical trials using peptides such as MAGE-1 or MAGE-3 are in progress for malignant melanoma (Mukherji et al, 1995;Marchand et al, 1995).…”

Comparison of the Accessory Activity of Murine Peritoneal Cavity Macrophage Derived Dendritic Cells and Peritoneal Cavity Macrophages in a Mixed Lymphocyte Reaction.

“…Professional APC are characterized by their constitutive high levels of major histocompartibility complex (MHC) class II expression, poor phagocytic ability, lack of sIg and Fc receptors, weak adherence to solid supports [34] and their ability to stimulate primed T cell proliferation in an antigen specific manner [29]. Studies have clearly shown that peritoneal macrophages are highly proliferating progenitors for functional DC [24,28]. Several groups have succeeded in generating large numbers of functional DC from their proliferating progenitors located in bone marrow, spleen or blood in the presence of appropriate cytokines [2-4, 8, 10, 18, 19, 22].…”

Dendritic cell vaccination for cancer therapy

“…First preliminary data on the e ciency of antigen-presenting cells such as GM-CSF stimulated monocytes injected intradermally were obtained in melanoma patients. Induction of MAGE-1 MHC class I restricted peptide speci®c CTL were induced by vaccination which also recognized autologous melanoma cells, however in the absence of signi®cant clinical response (Hu et al, 1996;Mukherji et al, 1995). A pilot study using idiotype protein pulsed DC generated from circulating DC precursors (Markowicz and Engleman, 1990) was performed in four patients with malignant B cell lymphoma who had failed conventional chemotherapy.…”