Renal cell carcinomas (RCCs) are supposed to be immunogenic, and several clinical trials of immunotherapy using tumor lysatepulsed dendritic cells (DCs) have been performed. We report on the generation of RAGE-1 and MAGE-9 peptide-specific CTL lines. RAGE-1 and MAGE-9 are expressed in 56% and 38% of RCCs. Seven MAGE-9-and 13 RAGE-1-derived peptides were found to be immunogenic in the context of the HLA-A*0201 MHC. CTLs were generated by coculture with peptide-pulsed, activated B cells, which were easily generated in great quantities and displayed functional activity for a prolonged period of time. MAGE-9 and RAGE-1 peptide-specific CTL lines were strictly peptide-specific and displayed high cytotoxic activity not only against peptide-loaded T2 cells but also against HLA-A*0201-positive RCC lines, which naturally express MAGE-9, RAGE-1 or both. Thus, B cells are well suited as APCs for the generation of large numbers of tumor peptide-specific CTLs for adoptive transfer. MAGE-9 as well as RAGE-1 may well provide suitable targets for immunotherapy of RCC. ' 2005 Wiley-Liss, Inc.Key words: human renal cell carcinoma; antigen-presenting cell; peptide-specific cytotoxic T lymphocyte With 1-2% of solid tumors, RCCs are less frequent than prostate and bladder carcinomas.1 However, the prognosis of patients with RCC is poor as one-third of patients already have metastatic disease at the initial presentation and 30-40% develop distant metastases after resection of the primary tumor.2,3 Median survival time of metastatic RCC is only 6-8 months, and the 5-year survival rate is <5%. As >80% of RCCs express the phenotype of multidrug resistance, chemotherapy is rarely efficient. [4][5][6] However, RCCs are supposed to be immunogenic; 7-11 hence, immunotherapeutic strategies are dominant. should be mentioned. The antibody becomes internalized, 32 and application of 125 I-coupled G250 has been reported to retard tumor progression. 33-35Cell-mediated immunotherapeutic protocols in RCC have been based on tumor lysate-loaded DCs.36-39 Vaccination-induced remissions and an increase in the 5-year survival rate to 70% have been observed. [40][41][42] Application of tumor antigen cDNA 43 or of DC transduced with tumor antigen mRNA or cDNA 44,45 has been reported also to improve survival time, albeit to a minor degree. For antigen-specific vaccination in RCC, 46,47 so far MUC1, HSP96 and MN/CAIX have been used. Yet, the therapeutic efficacy remains below expectation. [48][49][50][51] We previously observed, by SSH, expression of MAGE-9 in RCC.52 As RAGE-1 has been described as an immunogenic RCC-associated antigen, [53][54][55] we explored the frequency of MAGE-9 expression in RCC and identified HLA-A*0201-restricted immunogenic MAGE-9 peptides in comparison to RAGE-1. We also report on the efficacy of B cells in peptide presentation and stimulation of peptide-specific CTLs. Material and methods Tumor linesHuman RCC lines 769-p, 56 Caki-1 and Caki-2, 57 ACHN, KTCTL-28, KTCTL-30, KTCTL-53 and KTCTL-111 (tumor bank,

Growing evidence indicates that multiple myeloma (MM) and other malignancies are susceptible to CTL-based immune interventions. We studied whether transcription factors inherently involved in the terminal differentiation of mature B lymphocytes into malignant and nonmalignant plasma cells provide MM-associated CTL epitopes. HLA-A*0201 (A2.1) transgenic mice were used to identify A2.1-presented peptide Ag derived from the plasma cell-associated transcriptional regulators, positive regulatory domain I-binding factor 1 (PRDI-BF1) and X box-binding protein 1 (XBP-1). A2.1-restricted CTL specific for PRDI-BF1 and XBP-1 epitopes efficiently killed a variety of MM targets. PRDI-BF1- and XBP-1-reactive CTL were able to recognize primary MM cells from A2.1+ patients. Consistent with the expression pattern of both transcription factors beyond malignant and nonmalignant plasma cells, PRDI-BF1- and XBP-1-specific CTL activity was not entirely limited to MM targets, but was also associated with lysis of certain other malignancies and, in defined instances, with low-to-intermediate level recognition of a few types of normal cells. Our results also indicate that the A2.1-restricted, PRDI-BF1- and XBP-1-specific human CD8+ T cell repertoire is affected by partial self tolerance and may thus require the transfer of high-affinity TCR to break tolerance. We conclude that transcription factors governing terminal cellular differentiation may provide MM- and tumor-associated CTL epitopes.

No abstract

Renal cell carcinoma (RCC) are supposed to be immunogenic and several clinical trials of immunotherapy using tumor-lysate pulsed dendritic cells have been performed. We here report on the generation and therapeutic efficacy of RAGE-1 and MAGE-9 peptide specific cytotoxic T cell clones.RAGE-1 and MAGE-9 are expressed on 61% and 40% of RCC. Six MAGE-9 and 14 RAGE-1 derived peptides were found to be immunogenic in the context of the HLA-A2.1 MHC complex. CTL were generated by co-culture with peptide pulsed dendritic cells (DC) or peptide pulsed CD40-activated B cells. The latter are as efficient in antigen presentation as DC, but have the advantage of being easier to generate in great quantitities and to display functional activity for a prolonged period of time. Therefore, they are well suited for the generation of CTL clones to be used in adoptive transfer. Three MAGE-9 and RAGE-1 specific CTL clones were generated. The clones were strictly peptide-specific and displayed high cytotoxic activity not only against peptide-loaded T2 cells, but also against HLA-A2.1-positive RCC lines that naturally expressed MAGE-9, RAGE-1 or both. The in vivo efficacy of these MAGE-9 and RAGE-1 peptide specific CTL clones is currently being evaluated in human RCC-bearing SCID, which received after intraperitoneal RCC injection repeated applications of the CTL clones at weekly intervals. So far, the majority of control mice became moribund, but only one mouse receiving a MAGE-9 and a RAGE-1 specific CTL developed a tumor, that had retained MHC class I as well as MAGE-9 and RAGE-1 expression. CTL recovered from these mice at 2 and 3 weeks after the last T cell transfer revealed that CTL had retained their specificity and cytotoxic activity was only slightly reduced.Thus, B cells appear well suited as antigen presenting cells for the generation of large quantities tumor peptide specific CTL as required for adoptive transfer and cancer testis antigens may well provide suitable target for immunotherapy of RCC.