Targets For Specific Immunotherapy Research Articles

Cytoskeleton regulator RNA expression on cancer-associated fibroblasts is associated with prognosis and immunotherapy response in bladder cancer

BackgroundDysregulation of long noncoding RNAs (lncRNAs) has been reported to be associated with multiple tumors where they act as tumor suppressors or accelerators. The lncRNA CYTOR was identified as an oncogene involved in many cancers, such as gastric cancer, colorectal cancer, hepatocellular carcinoma, and renal cell carcinoma. However, the role of CYTOR in bladder cancer (BCa) has rarely been reported. MethodsUsing cancer datasets from The Cancer Genome Atlas (TCGA) program, we analyzed the association between CYTOR expression and prognostic value, oncogenic pathways, antitumor immunity and immunotherapy response in BCa. The influence of CYTOR on the immune infiltration pattern in the urothelial carcinoma microenvironment was further verified in our dataset. Single-cell analysis revealed the role of CYTOR in the tumor microenvironment (TME) of BCa. Finally, we evaluated the expression of CYTOR in BCa in the Peking University First Hospital (PKU–BCa) dataset and its correlation with the malignant phenotype of BCa in vitro and in vivo. ResultsThe results indicated that CYTOR was highly expressed in multiple cancer samples, including BCa, and increased CYTOR expression contributed to poor overall survival (OS). Additionally, elevated CYTOR expression was significantly correlated with clinicopathological features of BCa, such as female sex, advanced TNM stage, high histological grade and non-papillary subtype. Functional characterization revealed that CYTOR may be involved in immune-related pathways and the epithelial mesenchymal transformation (EMT) process. Moreover, CYTOR had a significant association with infiltrating immune cells, including M2 macrophages and regulatory T cells (Tregs). CYTOR facilitates the crosstalk between cancer-associated fibroblasts (CAFs) and macrophages, and mediates M2 polarization of macrophages. Correlation analysis revealed a positive correlation between CYTOR expression and programmed cell death-1 (PD-1)/programmed death ligand 1 (PD-L1)/expression and other targets for specific immunotherapy in BCa, which are recognized to predict the efficacy of immunotherapy. ConclusionsThese results suggest that CYTOR serves as a potential biomarker for predicting survival outcome, TME cell infiltration characteristics and immunotherapy response in BCa.

The cancer testis antigens CABYR-a/b and CABYR-c are expressed in a subset of colorectal cancers and hold promise as targets for specific immunotherapy.

Introduction: Calcium-binding tyrosine phosphorylation-regulated protein (CABYR) is expressed in the human germ line but not in adult human tissues, thus, it is considered a cancer testis protein. The aim of this study is to evaluate the CABYR isoforms: a/b and c mRNA expression in colorectal cancer (CRC) and to determine if these proteins hold promise as vaccine targets.Materials and Methods: CABYR mRNA expression in a set of normal human tissues, including the testis, were determined and compared using semi-quantitative PCR. As regards the tumor and normal mucosal samples from study patients, RNA was extracted and cDNA generated after which quantitative PCR was carried out. Analysis of CABYR protein expressions by immunohistochemistry in tumor and normal colon tissues was also performed.Results: A total of 47 paired CRC and normal tissue specimens were studied. The percent of patients with a relative expression ratio of malignant to normal (M/N) tissues over 1 was 70% for CABYR a/b and 72% for CABYR c. The percent with both a M/N ratio over 1 and expression levels over 0.1% of testis was 23.4% for CABYR-a/b and 25.5% for CABYR c. CABYR expression in tumors was further confirmed by immunohistochemistry.Conclusions: CABYR a/b and c hold promise as specific immunotherapy targets, however, a larger and more diverse group of tumors (Stage 1-4) needs to be assessed and evaluation of blood for anti-CABYR antibodies is needed to pursue this concept.

Expression of gene MAGE-A4 in Reed-Sternberg cells

AbstractGenes of the MAGE-A family are expressed in several types of solid tumors but are silent in normal tissues with the exception of male germline cells, which do not carry HLA molecules.Therefore, peptides encoded by MAGE-A genes are strictly tumor-specific antigens that can be recognized by CTL and constitute promising targets for immunotherapy. The expression of 6 genes of the MAGE-A family was tested with reverse transcriptase-polymerase chain reaction in lymphoma samples. Among 38 samples of non-Hodgkin lymphoma, 1 anaplastic large cell lymphoma expressed genes MAGE-A1, -A2, -A3, -A4, and -A12, and 1 lymphoepithelioid T-cell lymphoma expressed geneMAGE-A4. Five of 18 samples (28%) from patients with Hodgkin disease expressed gene MAGE-A4. In tissue sections, staining by a monoclonal antibody that recognizes the MAGE-A4 protein was observed in 11 of 53 samples (21%) from patients with Hodgkin disease. In the positive samples, the Reed-Sternberg cells were strongly stained whereas the surrounding cells were not. These results indicate that Hodgkin disease may be a target for specific immunotherapy involving MAGE-A4 antigens.

Treatment of Multiple Myeloma Using Chimeric Antigen Receptor T Cells with Dual Specificity.

Chimeric antigen receptor (CAR) T-cell therapy has shown remarkable successes in fighting B-cell leukemias/lymphomas. Promising response rates are reported in patients treated with B-cell maturation antigen (BCMA) CAR T cells for multiple myeloma. However, responses appear to be nondurable, highlighting the need to expand the repertoire of multiple myeloma-specific targets for immunotherapy and to generate new CAR T cells. Here, we developed a "dual-CAR" targeting two multiple myeloma-associated antigens and explored its safety and efficacy. To reduce the "off-target" toxicity, we used the recognition of paired antigens that were coexpressed by the tumor to induce efficient CAR T-cell activation. The dual-CAR construct presented here was carefully designed to target the multiple myeloma-associated antigens, taking into consideration the distribution of both antigens on normal human tissues. Our results showed that the CD138/CD38-targeted dual CAR (dCAR138-38) elicited a potent anti-multiple myeloma response both in vitro and in vivo NSG mice transplanted with a multiple myeloma cell line and treated with dCAR138-38 showed median survival of 97 days compared with 31 days in the control group treated with mock-lymphocytes. The dCAR138-38 showed increased specificity toward cells expressing both targeted antigens compared with single-antigen-expressing cells and low activity toward primary cells from healthy tissues. Our findings indicated that the dCAR138-38 may provide a potent and safe alternative therapy for patients with multiple myeloma.

Efficient induction of cytotoxic T lymphocytes in hepatocellular carcinoma using the HLA-A2-restricted survivin peptide in vitro

Survivin is a newly identified tumour-associated antigen and has been demonstrated to be an excellent target for immunotherapy in several cancers, but its role in hepatocellular carcinoma treatment is still unknown. In this study, survivin-derived peptide-specific cytotoxic T lymphocytes (CTLs) from peripheral blood mononuclear cells of healthy donors were induced by multiple stimulations with HLA-A2- restricted survivin peptide-pulsed T2 cells. The induced CTLs exhibited specific lysis of T2 cells pulsed with the peptide and HLA-A2+ hepatocellular carcinoma cells expressing survivin, while HLA-A2+ hepatocellular carcinoma cell lines that did not express survivin were not recognized by the CTLs. These results suggest that the survivin peptide epitope could be a potential target of specific immunotherapy for HLA-A2+ patients with hepatocellular carcinoma.

Expression profile of SPACA5/Spaca5 in spermatogenesis and transitional cell carcinoma of the bladder.

The majority of bladder cancer-associated mortalities are due to transitional cell carcinoma (TCC), which is the most prevalent and chemoresistant malignancy of the bladder. Sperm acrosome associated 5 (SPACA5)/Spaca5 is a sperm acrosome-associated, c-type lysozyme-like protein that has been recently identified, and has been designated as an attractive candidate antigen for cancer testis. In the present study, the expression profile of SPACA5/Spaca5 was analyzed in spermatogenesis and TCC of the bladder using diverse molecular and cellular biology methods. Using reverse transcription-polymerase chain reaction (RT-PCR) to analyze the multi-tissue distribution and temporal expression of SPACA5/Spaca5, the SPACA5/Spaca5 gene was determined to be generally not expressed in normal tissue, with the exception of the testis, and it could be detected at a low level on day 20 after birth in mouse testes and at a higher level on day 28. Immunohistochemistry staining revealed that the SPACA5/Spaca5 protein was exclusively observed in the elongated spermatid of the normal testes, and was ectopically expressed in the cytoplasm of TCC, while it was not expressed in normal bladder tissues. The frequency of SPACA5 messenger RNA was detected in 45% of TCC (9/20) by RT-quantitative PCR. Furthermore, SPACA5 protein was more frequently detected in high-grade than in low-grade tumors (61.54 vs. 30.00%, P=0.035). Accordingly, high SPACA5 staining scores were observed to be significantly associated with high-grade tumors (n=65, R=0.279, P=0.027). Collectively, our findings indicated that SPACA5/Spaca5 may be important in male spermatogenesis and may be used as a potential target for specific immunotherapy in patients suffering from TCC.

Concise Review: Targeting Cancer Stem Cells Using Immunologic Approaches.

Cancer stem cells (CSCs) represent a small subset of tumor cells which have the ability to self-renew and generate the diverse cells that comprise the tumor bulk. They are responsible for local tumor recurrence and distant metastasis. However, they are resistant to conventional radiotherapy and chemotherapy. Novel immunotherapeutic strategies that specifically target CSCs may improve the efficacy of cancer therapy. To immunologically target CSC phenotypes, innate immune responses to CSCs have been reported using Natural killer cells and γδ T cells. To target CSC specifically, in vitro CSC-primed T cells have been successfully generated and shown targeting of CSCs in vivo after adoptive transfer. Recently, CSC-based dendritic cell vaccine has demonstrated significant induction of anti-CSC immunity both in vivo in immunocompetent hosts and in vitro as evident by CSC reactivity of CSC vaccine-primed antibodies and T cells. In addition, identification of specific antigens or genetic alterations in CSCs may provide more specific targets for immunotherapy. ALDH, CD44, CD133, and HER2 have served as markers to isolate CSCs from a number of tumor types in animal models and human tumors. They might serve as useful targets for CSC immunotherapy. Finally, since CSCs are regulated by interactions with the CSC niche, these interactions may serve as additional targets for CSC immunotherapy. Targeting the tumor microenvironment, such as interrupting the immune cell, for example, myeloid-derived suppressor cells, and cytokines, for example, IL-6 and IL-8, as well as the immune checkpoint (PD1/PDL1, etc.) may provide additional novel strategies to enhance the immunological targeting of CSCs.

A combined approach of human leukocyte antigen ligandomics and immunogenicity analysis to improve peptide-based cancer immunotherapy.

The breakthrough development of immune checkpoint inhibitors as clinically effective novel therapies demonstrates the potential of cancer immunotherapy. The identification of suitable targets for specific immunotherapy, however, remains a challenging task. Most peptides previously used for vaccination in clinical trials were able to elicit strong immunological responses but failed with regard to clinical benefit. This might, at least partly, be caused by an inadequate peptide selection, usually derived from established tumor-associated antigens which are not necessarily presented as human leukocyte antigen (HLA) ligands. Recently, HLA ligandome analysis revealed cancer-associated peptides, which have been used in clinical trials showing encouraging impact on survival. To improve peptide-based cancer immunotherapy, our group established a combined approach of HLA ligandomics and immunogenicity analysis for the identification of vaccine peptides. This approach is based on the identification of naturally presented HLA ligands on tumor samples, the selection of tumor-associated/tumor-specific HLA ligands and their subsequent testing for immunogenicity in vitro. In this review, we want to present our pipeline for the identification of vaccine peptides, focusing on ovarian cancer, and want to discuss differences to other approaches. Furthermore, we want to give a short outlook of a potential multi-peptide vaccination trial using the novel identified peptides.

Circulating cell-free cancer-testis MAGE-A RNA, BORIS RNA, let-7b and miR-202 in the blood of patients with breast cancer and benign breast diseases.

Background:MAGE-A (melanoma-associated antigen-A) are promising targets for specific immunotherapy and their expression may be induced by the epigenetic factor BORIS.Methods:To determine their relevance for breast cancer, we quantified the levels of MAGE-A1, -A2, -A3, -A12 and BORIS mRNA, as well as microRNAs let-7b and miR-202 in pre- and postoperative serum of 102 and 34 breast cancer patients, respectively, and in serum of 26 patients with benign breast diseases and 37 healthy women by real-time PCR. The mean follow-up time of the cancer patients was 6.2 years.Results:The serum levels of MAGE-A and BORIS mRNA, as well as let-7b were significantly higher in patients with invasive carcinomas than in patients with benign breast diseases or healthy women (P<0.001), whereas the levels of miR-202 were elevated in both patient cohorts (P<0.001). In uni- and multivariate analyses, high levels of miR-202 significantly correlated with poor overall survival (P=0.0001). Transfection of breast cancer cells with synthetic microRNAs and their inhibitors showed that let-7b and miR-202 did not affect the protein expression of MAGE-A1.Conclusions:Based on their cancer-specific increase in breast cancer patients, circulating MAGE-A and BORIS mRNAs may be further explored for early detection of breast cancer and monitoring of MAGE-directed immunotherapies. Moreover, serum miR-202 is associated with prognosis.

6 Cancer-testis antigens as potential targets for specific immunotherapy in prostate cancer

6 Cancer-testis antigens as potential targets for specific immunotherapy in prostate cancer

Programmed cell death-ligand 1 expression in surgically resected stage I pulmonary adenocarcinoma and its correlation with driver mutations and clinical outcomes

BackgroundProgrammed cell death-ligand 1 (PD-L1) is expressed in a group of cancers that may be suitable targets for specific immunotherapy. This study investigated the expression of PD-L1 in surgically resected stage I adenocarcinomas and correlated this with known major driver mutations and clinical outcomes. Materials and methodsOne hundred and sixty-three patients with surgically resected stage I adenocarcinomas were explored. Paraffin-embedded tumour sections were stained with PD-L1 antibody. Tumours with moderate-to-strong membrane staining in ⩾5% of tumour cells were scored as positive for PD-L1 overexpression. The driver mutation epidermal growth factor receptor (EGFR), Kirsten rat sarcoma viral oncogene homolog (KRAS), and v-raf murine sarcoma viral oncogene homolog B (BRAF) were examined by direct sequencing and anaplastic lymphoma kinsase (ALK) by immunohistochemistry. The correlations of PD-L1 expression with major driver mutations and clinicopathologic parameters were analysed. ResultsThe overall frequency of PD-L1 overexpression was 39.9% (65/163). PD-L1 had higher positive results in tumours with higher grade differentiation and vascular invasion and PD-L1 expression was not associated with the expressions of EGFR, KRAS, BRAF and ALK. Multivariate analysis revealed that abnormal carcinoembryonic antigen (CEA) and higher grade of differentiation were risk factors for poor relapse-free survival (RFS) and PD-L1 expression correlated with better RFS. Advanced pathologic stage was the independent risk for poor overall survival (OS). ConclusionsThe PD-L1 expression can be used as a prognostic indicator predictive of RFS in patients with surgically resected stage I lung adenocarcinomas. There may be a possibility for immunotherapy targeting the PD-L1 pathway in patients with lung adenocarcinoma in the future.

Poster 1020: Efficacy and safety of sublingual specific immunotherapy with Pru p 3 in a portuguese population - clinical and immunological evaluation during 12 months

Background Peach allergy is prevalent, persistent and potentially severe. LTPs (Pru p 3) and profilins (Pru p 4) are the main allergens involved in this kind of allergy in patients(pts) of Mediterranean area. The hidden presence of LTPs in foodstuffs and in other food involved in LTP syndrome can trigger severe reactions, including anaphylaxis. Thus, this type of allergy can be considered an important target for specific immunotherapy(IT).

Analysis Of Leukemic Stem Cell Population Comparing NPM1wt and NPM1mut AML Patients and Potential Therapeutic Targets

Treatment of acute myeloid leukemia (AML) patients became more effective, yet the relapse rate is still high and cure rate still low. Different therapeutic approaches, based on molecular targeting are offering new treatment strategies using markers like FLT3, NPM1, cKIT and DNMT3A. Many others are currently under investigation. Leukemic stem cells (LSC) might be the source for leukemic disease self-renewal and account for disease relapse after treatment. Therefore LSC represent a critical target for further therapeutic options. AML with mutated nucleophosmin (NPM1) gained attention because of its distinctive molecular, clinical, and prognostic features. NPM1 mutation is also an interesting target for specific immunotherapy (Greiner et al., Blood 2012), however LSC of this new entity have not been completely characterized. Differentially expressed genes might influence molecular and immunological relevant pathways which could have an impact on the better overall survival of the mutated patients.In this study, we were interested in expression differences of the LSC enriched cell fraction descendent of NPM1wt and NPM1mut primary AML patients. We suggest that expression differences between the patients groups could be a factor for the better overall survival of NPM1mut patients. In addition we aimed to study new targets on NPM1mut LSC for new therapeutical purposes.We enriched the CD34+CD38- fraction of primary AML peripheral blood mononuclear cells (PBMC), by Fluorescence-activated cell sorting (FACS) and Magnetic-activated cell sorting (MACS), comparing both methods in efficiency and feasibility. We chose FACS for further enrichment assays, as it resulted in a mean purity of 92% vs 88% using MACS, and a higher cell number after sorting (9% more) in the first pilot trials. We sorted 21 AML patient samples; 12 NPM1wt and 9 NPM1mut. We also enriched healthy donor samples for HSC purification using FACS, in order to compare expression levels. We showed that enriched CD34+CD38- cells in NPM1mut AML samples harbor cytoplasmic NPM1 via immunocytochemical staining, indicating that these cells belong to the leukemic clone. The cell number and RNA quality was sufficient for further Microarray studies in which we analysed the CD34+CD38- enriched compartments descendent from NPM1mut and NPM1wt patients. Those showed significant differences in gene expression patterns which noticeably are immunologically coined, for example: immunoglobulin superfamily, member 10 (p = 0.0003405; fold change: 6.22) and the interleukin 12 receptor, beta 1 (p = 0.000834, fold change: 1.87). This impression was confirmed by pathway analysis indicating deregulation of pathways like the NO2-dependent IL 12 Pathway in NK cells and the Th1/Th2 Differentiation and the Platelet Amyloid Precursor Protein Pathway.Functional assays, confirming the biological importance of these factors have been performed for example an assay to test the effect of IL12 on AML cellines.Furthermore we screened our data for new potential therapeutic target structures, specifically on enriched CD34+CD38- cells of NPM1mut patients, comparing the expression level of target genes to NPM1wt CD34+CD38- cells, and the expression level on HSC. Amongst others, our most promising candidates are SERPINA1 (p = 0.0062344, fold change: 14.32), OSCAR (p = 6.11E-05, fold change: 9.03) and several further interesting genes. These genes could be used in order to target CD34+CD38- cells of NPM1mut patients in a therapeutic manner.Taken together, we successfully enriched the CD34+CD38- fraction of NPM1mut and NPM1wt AML patients and performed Microarray analysis, unraveling gene expression differences between the two patients groups, which seem to be of an immunological nature. This could be a factor, amongst others, for the better overall survival of the NPM1mut patient group. Furthermore we described new potential targets structures on CD34+CD38- cells for NPM1mut patient's treatment. Disclosures:No relevant conflicts of interest to declare.

Small molecule inhibitor of antigen binding and presentation by HLA-DR2b as a therapeutic strategy for the treatment of multiple sclerosis.

The strong association of HLA-DR2b (DRB1*1501) with multiple sclerosis (MS) suggests this molecule as prime target for specific immunotherapy. Inhibition of HLA-DR2b-restricted myelin-specific T cells has the potential to selectively prevent CNS pathology mediated by these MHC molecules without undesired global immunosuppression. In this study, we report development of a highly selective small molecule inhibitor of peptide binding and presentation by HLA-DR2b. PV-267, the candidate molecule used in these studies, inhibited cytokine production and proliferation of myelin-specific HLA-DR2b-restricted T cells. PV-267 had no significant effect on T cell responses mediated by other MHC class II molecules, including HLA-DR1, -DR4, or -DR9. Importantly, PV-267 did not induce nonspecific immune activation of human PBMC. Lastly, PV-267 showed treatment efficacy both in preventing experimental autoimmune encephalomyelitis and in treating established disease. The results suggest that blocking the MS-associated HLA-DR2b allele with small molecule inhibitors may be a promising therapeutic strategy for the treatment of MS.

Immunohistochemical analysis of the expression of MAGE-A and NY-ESO-1 cancer/testis antigens in diffuse large B-cell testicular lymphoma

BackgroundPrimary testicular lymphoma (PTL) is a rare and lethal disease. The most common histological subtype is diffuse large B-cell lymphoma (DLBCL). Standard treatments are frequently ineffective. Thus, the development of novel forms of therapy is urgently required. Specific immunotherapy generating immune responses directed against antigen predominantly expressed by cancer cells such as cancer-testis antigens (CTA) may provide a valid alternative treatment for patients bearing PTL, alone or in combination with current therapies.MethodsThree monoclonal antibodies (mAbs), 77B recognizing MAGE-A1, 57B recognizing an epitope shared by multiple MAGE-A CTA (multi-MAGE-A specific) and D8.38 recognizing NY-ESO-1/LAGE-1 were used for immunohistochemical staining of 27 PTL, including 24 DLBCL.ResultsExpression of MAGE-A1 was infrequently detectable in DLBCL specimens (12.50%), whereas multi-MAGE-A and NY-ESO-1/LAGE-1 specific reagents stained the cytoplasms of tumor cells in DLBCL specimens with higher frequencies (54.17% and 37.50%, respectively) with different expression levels.ConclusionsThese results suggest that MAGE-A and NY-ESO-1/LAGE-1, possibly in combination with other CTA, might be used as targets for specific immunotherapy in DLBCL.

Specific immune responses against epitopes derived from Aurora kinase A and B in acute myeloid leukemia

Aurora kinases are serine/threonine kinases which play an important role in the process of mitosis and cell cycle regulation. Aurora kinase inhibitors are described to sensitize malignant cells to cytosine arabinoside and specific antibodies by mediating apoptosis. Aurora kinases are overexpressed in most acute leukemias but also in solid tumors. In this study we investigated whether epitopes derived from Aurora kinase A and B are able to elicit cellular immune responses in patients with acute myeloid leukemia (AML) to investigate their role as potential targets for specific immunotherapy. Samples of eight patients with AML were analyzed in enzyme-linked immunosorbent spot (ELISpot) assays and compared with immune responses of nine healthy volunteers (HVs). Specific CD8 + T cell responses were detected against the epitopes Aura A1, A2, B1, B2, B3, B4 and B5. Immune responses for epitopes derived from Aura B were induced more frequently compared to Aura A. The antigens with the most frequent cytotoxic T-lymphocyte (CTL) responses were Aura B3, B4 and B5, although the number of patients tested for these antigens was low. Aura B5 did not elicit specific CTL responses in HVs. For epitope Aura B6 no immune response was detected in HVs or patients. Taken together, with the combination of Aurora kinase inhibitors and an immunotherapeutic approach, an effective blast and minimal residual disease elimination might be achieved.

MAGE‐A10 cancer/testis antigen is highly expressed in high‐grade non‐muscle‐invasive bladder carcinomas

Bladder cancer is a common urinary malignancy and a prevalent cause of cancer-related death. Current therapies of early stage non-muscle-invasive bladder cancer (NMIBC) are frequently associated with undesirable toxicities and recurrence. Active antigen-specific immunotherapy may provide a valid therapeutic option for patients with NMIBC. Cancer-testis antigens (CTA) expressed in various tumour types and in a limited range of healthy tissues may represent potential targets for specific immunotherapy. MAGE-A10 is probably the most immunogenic antigen of the MAGE-A family. We evaluated the expression of MAGE-A10 in NMIBC. Seventy-nine patients undergoing surgical treatment for NMIBC were enrolled in the study. MAGE-A10 gene expression was assessed by quantitative real-time polymerase chain reaction. Immunohistochemistry was performed on paraffin-embedded sections. MAGE-A10 gene was specifically expressed in one-third of NMIBC (n = 24: 32.43%). Gene expression was correlated with high tumour grade. MAGE-A10 protein was exclusively detectable in nuclei of tumour cells. More importantly, MAGE-A10 protein was also more frequently detectable in high-grade tumours (p = 0.0001) and in stage T1 tumours invading subepithelial tissue or lamina propria (p = 0.01). A strong correlation between MAGE-A10 staining score and tumour grade and stage could accordingly be observed. These data indicate that MAGE-A10 expression is a feature of aggressive NMIBC and might be used as a novel target for specific immunotherapy of these cancers.

A unique MUC1-2-VNTR DNA vaccine suppresses tumor growth and prolongs survival in a murine multiple myeloma model

Multiple myeloma (MM) is a clonal B-cell malignancy charactered by the aberrant proliferation of malignant plasma cells in the bone marrow. MM is still an incurable malignancy. In this regard, novel treatments are urgently required. MUC1 (mucin 1), a type І transmembrane protein, is overexpressed and aberrantly glycosylated in many carcinomas particularly in MM resulting in an antigenically distinct molecule and may be a potential target for specific immunotherapy. In this study, we first designed a unique DNA vaccine, termed MUC1-2-VNTR (various number tandem repeats) to investigate whether the vaccine could specifically suppress tumor growth in a murine multiple myloma model. Our results showed that the constructed DNA vaccine pcDNA3.1-VNTR elicited both humoral and cellular tumor-specific immune responses in the MM mouse model leading to delay in tumor growth and prolonged survival of the mice. Consequently, our study indicates that this DNA vaccine shows promise to be used as a novel strategy for the treatment of MM.

Immunogenic Targets for Specific Immunotherapy in Multiple Myeloma

Multiple myeloma remains an incurable disease although the prognosis has been improved by novel therapeutics and agents recently. Relapse occurs in the majority of patients and becomes fatal finally. Immunotherapy might be a powerful intervention to maintain a long-lasting control of minimal residual disease or to even eradicate disseminated tumor cells. Several tumor-associated antigens have been identified in patients with multiple myeloma. These antigens are expressed in a tumor-specific or tumor-restricted pattern, are able to elicit immune response, and thus could serve as targets for immunotherapy. This review discusses immunogenic antigens with therapeutic potential for multiple myeloma.

TCR-like Biomolecules Target Peptide/MHC Class I Complexes on the Surface of Infected and Cancerous Cells

The human leukocyte antigen (HLA; also called major histocompatibility, or MHC) class I system presents peptides that distinguish healthy from diseased cells. Therefore, the discovery of peptide/MHC class I markers can provide highly specific targets for immunotherapy. Over the course of almost two decades, various strategies have been used, with mixed success, to produce antibodies that have recognition specificity for unique peptide/MHC class I complexes that mark infected and cancerous cells. Using these antibody reagents, novel peptide/MHC class I targets have been directly validated on diseased cells and new insight has been gained into the mechanisms of antigen presentation. More recently, these antibodies have shown promise for clinical applications such as therapeutic targeting of cancerous and infected cells and diagnosis and imaging of diseased cells. In this review, the authors comprehensively describe the methods used to identify disease-specific peptide/MHC class I epitopes and generate antibodies to these markers. Finally, they offer several examples that illustrate the promise of using these antibodies as anti-cancer agents.