The cancer-testis/cancer-germline antigen NY-ESO-1 is a vaccine target in epithelial ovarian cancer (EOC), but its limited expression is a barrier to vaccine efficacy. As NY-ESO-1 is regulated by DNA methylation, we hypothesized that DNA methyltransferase (DNMT) inhibitors may augment NY-ESO-1 vaccine therapy. In agreement, global DNA hypomethylation in EOC was associated with the presence of circulating antibodies to NY-ESO-1. Pre-clinical studies using EOC cell lines showed that decitabine treatment enhanced both NY-ESO-1 expression and NY-ESO-1-specific CTL-mediated responses. Based on these observations, we performed a phase I dose-escalation trial of decitabine, as an addition to NY-ESO-1 vaccine and doxorubicin liposome (doxorubicin) chemotherapy, in 12 patients with relapsed EOC. The regimen was safe, with limited and clinically manageable toxicities. Both global and promoter-specific DNA hypomethylation occurred in blood and circulating DNAs, the latter of which may reflect tumor cell responses. Increased NY-ESO-1 serum antibodies and T cell responses were observed in the majority of patients, and antibody spreading to additional tumor antigens was also observed. Finally, disease stabilization or partial clinical response occurred in 6/10 evaluable patients. Based on these encouraging results, evaluation of similar combinatorial chemo-immunotherapy regimens in EOC and other tumor types is warranted.
CD4+ T cells provide help to enhance and sustain cytotoxic CD8+ T cell responses. A direct lytic role for this cell population in mouse models further supports the use of tumor-reactive CD4+ T cells for cancer immunotherapy. CTLA-4 blockade has been shown to expand antigen-specific cytotoxic CD4+ T cells in mouse models. We took advantage of spontaneous immunity to the NY-ESO-1 cancer-testis antigen to investigate quantitative and qualitative changes in antigen-specific CD4+ T cell responses after ipilimumab (anti-CTLA-4 monoclonal antibody) treatment in advanced melanoma patients. Four NY-ESO-1 seropositive melanoma patients were chosen upon the availability of suitable blood specimens for characterizing the functions of NY-ESO-1 antigen-specific CD4+ T cell response by enzyme-linked immunospot (ELISPOT), intracellular cytokine staining (ICS) and cytotoxicity assays. Multiple NY-ESO-1 antigen-specific CD4+ T cell responses with Th1 dominance were induced or enhanced after ipilimumab treatment in peripheral blood in all four patients. NY-ESO-1 antigen-specific CD4+ T cell lines established from all 4 patients after ipilimumab treatment recognized naturally processed NY-ESO-1 protein in antigen-presenting cells, expressed master transcription factor Eomesodermin (Eomes) and secreted perforin and Granzyme B. Finally, we demonstrated that these NY-ESO-1 antigen-specific CD4+ T cell lines directly lysed autologous melanoma cell lines expressing NY-ESO-1 in an MHC class II restricted manner. Our results show that antigen specific cytotoxic CD4+ T cell responses are induced after ipilimumab therapy in human cancer patients. Ipilimumab may induce the expression of lytic granules on antigen specific cytotoxic CD4+ T cells via Eomes, revealing a novel consequence of immunologic checkpoint blockade.
Cytotoxic T lymphocyte antigen-4; ipilimumab; NY-ESO-1; antibody; melanoma; cytotoxic CD4+ T cell
The MAGE cancer-testis antigens (CTA) are attractive candidates for immunotherapy. The aim of this study was to determine the frequency of expression, humoral immunity and prognostic significance of MAGE CTA in human epithelial ovarian cancer (EOC). mRNA or protein expression frequencies were determined for MAGE-A1, -A3, -A4, -A10 and -C1 (CT7) in tissue samples obtained from 400 patients with EOC. The presence of autologous antibodies against the MAGE antigens was determined from 285 serum samples. The relationships between MAGE expression, humoral immunity to MAGE antigens, and clinico-pathologic characteristics were studied. The individual frequencies of expression were as follows: A1: 15% (42/281), A3: 36% (131/390), A4: 47% (186/399), A10: 52% (204/395), C1: 16% (42/267). Strong concordant expression was noted with MAGE-A1:–A4, MAGE-A1:–C1 and MAGE-A4:–A10 (p<0.0005). Expression of MAGE-A1 or -A10 antigens resulted in poor progression free survival (PFS) (OR 1.44, CI 1.01–2.04, p = 0.044 and OR 1.3, CI 1.03–1.64, p = 0.03, respectively); whereas, MAGE-C1 expression was associated with improved PFS (OR 0.62, CI 0.42–0.92, p = 0.016). The improved PFS observed for MAGE-C1 expression, was diminished by co-expression of MAGE-A1 or -A10. Spontaneous humoral immunity to the MAGE antigens was present in 9% (27/285) of patients, and this predicted poor overall survival (log-rank test p = 0.0137). These findings indicate that MAGE-A1, MAGE-A4, MAGE-A3, and MAGE-A10 are priority attractive targets for polyvalent immunotherapy in ovarian cancer patients.
Survival after amputation for melanoma is short; however, rare long-term survivors are reported. The mechanism for durable systemic tumor control in patients with regional failure is not known. To explore whether systemic tumor immunity may be implicated, tumor and circulating immune responses were examined in a patient who survived disease-free 14 years after hip disarticulation.
A 71 year-old female with extensive regional metastases of melanoma in the left lower extremity underwent amputation for palliative reasons. Tumor was collected at surgery, and blood was collected during follow-up. Tumor sections were evaluated for lymphocytic infiltration and NY-ESO-1 expression by immunohistochemistry. Cellular immune responses to defined tumor antigens were evaluated by ELIspot assay, and antibody responses to a panel of tumor antigens were assayed by ELISA.
The patient's tumor had minimal lymphocytic infiltrate (Immunotype A). NY-ESO-1 was strongly expressed by the melanoma cells. Circulating T cell responses to NY-ESO-1 peptides were observed 6 and 12 years postoperatively, and antibodies to NY-ESO-1 were detected 2-6 years after surgery.
The patient described in this report experienced relentless regional tumor progression, with intravascular metastases, then 14-year systemic disease-free survival after palliative resection, without evidence of melanoma recurrence before death from other causes. Her immune response to NY-ESO-1 likely failed to control established regional metastases because T cells were unable to infiltrate them. It is possible, however, that among other factors, the host immune response may have contributed to systemic protection.
Melanoma; amputation for melanoma; NY-ESO-1; tumor immunity; antibody; T-cell
This multicenter, retrospective analysis assessed the efficacy and safety of ipilimumab in 33 patients with unresectable or metastatic mucosal melanoma. The study provides evidence that ipilimumab can result in durable antitumor effects in a subset of patients with mucosal melanoma, although the response rate was low.
The outcome of patients with mucosal melanoma treated with ipilimumab is not defined. To assess the efficacy and safety of ipilimumab in this melanoma subset, we performed a multicenter, retrospective analysis of 33 patients with unresectable or metastatic mucosal melanoma treated with ipilimumab. The clinical characteristics, treatments, toxicities, radiographic assessment of disease burden by central radiology review at each site, and mutational profiles of the patients' tumors were recorded. Available peripheral blood samples were used to assess humoral immunity against a panel of cancer-testis antigens and other antigens. By the immune-related response criteria of the 30 patients who underwent radiographic assessment after ipilimumab at approximately week 12, there were 1 immune-related complete response, 1 immune-related partial response, 6 immune-related stable disease, and 22 immune-related progressive disease. By the modified World Health Organization criteria, there were 1 immune-related complete response, 1 immune-related partial response, 5 immune-related stable disease, and 23 immune-related progressive disease. Immune-related adverse events (as graded by Common Terminology Criteria for Adverse Events version 4.0) consisted of six patients with rash (four grade 1, two grade 2), three patients with diarrhea (one grade 1, two grade 3), one patient with grade 1 thyroiditis, one patient with grade 3 hepatitis, and 1 patient with grade 2 hypophysitis. The median overall survival from the time of the first dose of ipilimumab was 6.4 months (range: 1.8–26.7 months). Several patients demonstrated serologic responses to cancer-testis antigens and other antigens. Durable responses to ipilimumab were observed, but the overall response rate was low. Additional investigation is necessary to clarify the role of ipilimumab in patients with mucosal melanoma.
Mucosal melanoma; Ipilimumab; CTLA-4; Immunotherapy; Cancer-testis antigens
We report a case of metastatic melanoma treated with palliative radiotherapy to the primary tumor. The patient also experienced regression of non-irradiated lesions, demonstrating the abscopal effect. Importantly, serology showed anti-MAGEA3 antibodies, documenting an association between the abscopal effect and a systemic anti-tumor immune response. Whereas the literature suggests immune activation after tumor irradiation, this case documents an anti-tumor response seen in direct association with abscopal clearance. Implications for radiation in melanoma immunotherapy are discussed.
abscopal effect; melanoma; immunotherapy; cancer-testis antigen
Recent insights into the genetic and somatic aberrations have initiated a new era of rapidly evolving targeted and immune-based treatments for melanoma. After decades of unsuccessful attempts to finding a more effective cure in the treatment of melanoma now we have several drugs active in melanoma. The possibility to use these drugs in combination to improve responses to overcome the resistance, to potentiate the action of immune system with the new immunomodulating antibodies, and identification of biomarkers that can predict the response to a particular therapy represent new concepts and approaches in the clinical management of melanoma. The third “Melanoma Research: “A bridge from Naples to the World” meeting, shortened as “Bridge Melanoma Meeting” took place in Naples, December 2 to 4th, 2012. The four topics of discussion at this meeting were: advances in molecular profiling and novel biomarkers, combination therapies, novel concepts toward integrating biomarkers and therapies into contemporary clinical management of patients with melanoma across the entire spectrum of disease stage, and the knowledge gained from the biology of tumor microenvironment across different tumors as a bridge to impact on prognosis and response to therapy in melanoma. This international congress gathered more than 30 international faculty members who in an interactive atmosphere which stimulated discussion and exchange of their experience regarding the most recent advances in research and clinical management of melanoma patients.
Background. Patients with recurrent synovial sarcomas have few options for systemic therapy. Since they express large amounts of endogenous CT (cancer testis) antigens such as NY-ESO-1, we investigated the clinical activity of single agent anti-CTLA4 antibody ipilimumab in patients with advanced or metastatic synovial sarcoma. Methods. A Simon two-stage phase II design was used to determine if there was sufficient activity to pursue further. The primary endpoint was tumor response rate by RECIST 1.0. Patients were treated with ipilimumab 3 mg/kg intravenously every 3 weeks for three cycles and then restaged. Retreatment was possible for patients receiving an extra three-week break from therapy. Sera and peripheral blood mononuclear cells were collected before and during therapy to assess NY-ESO-1-specific immunity. Results. Six patients were enrolled and received 1–3 cycles of ipilimumab. All patients showed clinical or radiological evidence of disease progression after no more than three cycles of therapy, for a RECIST response rate of 0%. The study was stopped for slow accrual, lack of activity, and lack of immune response. There was no evidence of clinically significant either serologic or delayed type hypersensitivity responses to NY-ESO-1 before or after therapy. Conclusion. Despite high expression of CT antigens by synovial sarcomas of patients treated in this study, there was neither clinical benefit nor evidence of anti-CT antigen serological responses. Assessment of the ability of synovial sarcoma cell lines to present cancer-germ cell antigens may be useful in determining the reason for the observed lack of immunological or clinical activity.
We investigated whether antibodies against intracellular tumor-associated antigens support tumor-specific immunity when administered together with a treatment that destroys the tumor. We propose that released antigens form immune complexes with the antibodies, which are then efficiently taken up by dendritic cells. We cloned the first human monoclonal antibodies against the Cancer/Testis (CT) antigen, NY-ESO-1. We tested whether the monoclonal anti-NY-ESO-1 antibody (12D7) facilitates cross-presentation of a NY-ESO-1-derived epitope by dendritic cells to human CD8+ T cells, and whether this results in the maturation of dendritic cells in vitro. We investigated the efficacy of 12D7 in combination with chemotherapy using BALB/c mice bearing syngeneic CT26 tumors that express intracellular NY-ESO-1. Human dendritic cells that were incubated with NY-ESO-1:12D7 immune complexes efficiently stimulated NY-ESO-1157–165/HLA-A2-specific human CD8+ T cells to produce interferon-γ, whereas NY-ESO-1 alone did not. Furthermore, the incubation of dendritic cells with NY-ESO-1:12D7 immune complexes resulted in the maturation of dendritic cells. Treatment of BALB/c mice that bear CT26/NY-ESO-1 tumors with 5-fluorouracil (5-FU) plus 12D7 was significantly more effective than chemotherapy alone. We propose systemic injection of monoclonal antibodies (mAbs) against tumor-associated antigens plus a treatment that promotes the local release of those antigens resulting in immune complex formation as a novel therapeutic modality for cancer.
NY-ESO-1; antibody; chemotherapy
The expression of Cancer/Testis (CT) antigens in some tumors and restricted expression in normal tissue make CT antigens attractive vaccine targets. We evaluated the expression of MAGE-A3, PLAC1, GAGE, and CTAG2 in a series of colorectal cancers (CRC). CT mRNA expression was determined via quantitative PCR on paired tumors and normal tissue samples from 82 CRC patients. In addition, plasma antibody titers specific to MAGE-A3, PLAC1, GAGE, and CTAG2 were determined via ELISA. Tissue expression of MAGE-A3 was assessed via a standard IHC protocol. The Student’s t-test was used for statistical analysis (significance p < 0.05). Tumor expression of MAGE-A3, CTAG2, and GAGE was compared to the levels of expression in testis. The percentage of samples that had a tumor vs. testis expression ratio above 0.1% was: MAGE-A3 (28%) and CTAG2 (17%) but no tumor presented GAGE expression levels above 0.1%. The expression levels of PLAC1 in tumors were compared to the levels in placenta, and in 12.8% of the samples analyzed, these levels were above 0.1%. Sero-reactivity specific for MAGE-A genes and PLAC1 was noted in 2.4% and 2.6% of patients, respectively. MAGE-A3 and PLAC1 may hold promise as vaccine targets for CRC. Further study is warranted.
MAGE-A3; tumor expression; colorectal cancer; Cancer/Testis antigens
Prediction of clinical outcome in cancer is usually achieved by histopathological evaluation of tissue samples obtained during surgical resection of the primary tumor. Traditional tumor staging (AJCC/UICC-TNM classification) summarizes data on tumor burden (T), presence of cancer cells in draining and regional lymph nodes (N) and evidence for metastases (M). However, it is now recognized that clinical outcome can significantly vary among patients within the same stage. The current classification provides limited prognostic information, and does not predict response to therapy. Recent literature has alluded to the importance of the host immune system in controlling tumor progression. Thus, evidence supports the notion to include immunological biomarkers, implemented as a tool for the prediction of prognosis and response to therapy. Accumulating data, collected from large cohorts of human cancers, has demonstrated the impact of immune-classification, which has a prognostic value that may add to the significance of the AJCC/UICC TNM-classification. It is therefore imperative to begin to incorporate the ‘Immunoscore’ into traditional classification, thus providing an essential prognostic and potentially predictive tool. Introduction of this parameter as a biomarker to classify cancers, as part of routine diagnostic and prognostic assessment of tumors, will facilitate clinical decision-making including rational stratification of patient treatment. Equally, the inherent complexity of quantitative immunohistochemistry, in conjunction with protocol variation across laboratories, analysis of different immune cell types, inconsistent region selection criteria, and variable ways to quantify immune infiltration, all underline the urgent requirement to reach assay harmonization. In an effort to promote the Immunoscore in routine clinical settings, an international task force was initiated. This review represents a follow-up of the announcement of this initiative, and of the J Transl Med. editorial from January 2012. Immunophenotyping of tumors may provide crucial novel prognostic information. The results of this international validation may result in the implementation of the Immunoscore as a new component for the classification of cancer, designated TNM-I (TNM-Immune).
The abscopal effect is a phenomenon in which local radiotherapy is associated with the regression of metastatic cancer at a distance from the irradiated site. The abscopal effect may be mediated by activation of the immune system. Ipilimumab is a monoclonal antibody that inhibits an immunologic checkpoint on T cells, cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4). We report a case of the abscopal effect in a patient with melanoma treated with ipilimumab and radiotherapy. Temporal associations were noted: tumor shrinkage with antibody responses to the cancer–testis antigen NY-ESO-1, changes in peripheral-blood immune cells, and increases in antibody responses to other antigens after radiotherapy. (Funded by the National Institutes of Health and others.)
Light-chain amyloidosis (AL) is a plasma cell dyscrasia closely related to multiple myeloma. In multiple myeloma, the cancer-testis antigens (CTAs) CT7 (MAGE-C1), CT10 (MAGE-C2) and MAGE-A CTAs are expressed in up to 80% of cases. In this study, we investigated the expression and immunogenicity of several CTAs in patients with AL amyloidosis in a total of 38 bone marrow specimens by employing standard immunohistochemistry techniques on paraffin-embedded archival tissues. Plasma samples from 35 patients (27 with matched bone marrow samples) were also analyzed by ELISA for sero reactivity to a group of full-length CTA proteins. CT7 was present in 25/38 (66%) while CT10 was demonstrated in 3/38 and GAGE in 1/38 AL amyloid cases. The expression pattern was mostly focal. There were no significant differences with regard to organ involvement, response to treatment, or prognosis in CTA positive compared to negative cases. None of the specimens showed spontaneous humoral immunity to CT7, but sero reactivity was observed in individual patients to other CTAs. This study identifies CT7 as the prevalent CTA in plasma cells of patients with AL amyloidosis. Further analyses determining the biology of CTAs in AL amyloidosis and their value as potential targets for immunotherapy are warranted.
AL amyloidosis; cancer-testis antigens; stem cell transplantation
NY-ESO-1 cancer testis (CT) antigen is an attractive candidate for immunotherapy as a result of its high immunogenicity. The aim of this study was to explore the potential for NY-ESO-1 antigen directed immunotherapy in triple negative breast cancer (TNBC) by determining the frequency of expression by immunohistochemistry (IHC) and the degree of inherent immunogenicity to NY-ESO-1.
168 TNBC and 47 ER+/HER2- primary breast cancer specimens were used to determine NY-ESO-1 frequency by IHC. As previous studies have shown that patients with a robust innate humoral immune response to CT antigens are more likely to develop CD8 T-cell responses to NY-ESO-1 peptides, we evaluated the degree to which patients with NY-ESO-1 expression had inherent immunogenicity by measuring antibodies. The relationship between NY-ESO-1 expression and CD8+ T lymphocytes was also examined.
The frequency of NY-ESO-1 expression in the TNBC cohort was 16% versus 2% in ER+/HER2- patients. A higher NY-ESO-1 score was associated with a younger age at diagnosis in the TNBC patients with NY-ESO-1 expression (p = 0.026). No differences in OS (p = 0.278) or PFS (p = 0.238) by NY-ESO-1 expression status were detected. Antibody responses to NY-ESO-1 were found in 73% of TNBC patients whose tumors were NY-ESO-1 positive. NY-ESO-1 positive patients had higher CD8 counts than negative patients (p = 0.018).
NY-ESO-1 is expressed in a substantial subset of TNBC patients and leads to a high humoral immune response in a large proportion of these individuals. Given these observations, patients with TNBC may benefit from targeted therapies directed against NY-ESO-1.
Tumor antigens NY-ESO-1 and p53 both frequently induce spontaneous serum antibody in cancer patients. While NY-ESO-1-specific CD8+ and CD4+ circulating T-cells occur mainly in NY-ESO-1-seropositive patients, p53-specific circulating CD8+ and CD4+ T-cells are respectively undetectable and common in most individuals. Understanding T-cell split tolerance can help define suitable targets for immunotherapy.
CD8 T lymphocytes; NY-ESO-1; Serum antibody; cancer vaccine; p53; tolerance; tumor antigen
We developed an in vitro method for isolating and expanding autologous CD4+ T-cell clones with specificity for the melanoma-associated antigen NY-ESO-1. We infused these cells into a patient with refractory metastatic melanoma who had not undergone any previous conditioning or cytokine treatment. We show that the transferred CD4+ T cells mediated a durable clinical remission and led to endogenous responses against melanoma antigens other than NY-ESO-1.
Analyses of NY-ESO-1-specific spontaneous immune responses in cancer patients revealed that antibody and both CD4+ and CD8+ T cell responses were induced together in cancer patients. To explore whether such integrated immune responses are also spontaneously induced for other tumor antigens, we have evaluated antibody and T cell responses against self/tumor antigen p53 in ovarian cancer patients and healthy individuals. We found that 21% (64/298) of ovarian cancer patients but no healthy donors showed specific IgG responses against wild-type p53 protein. While none of 12 patients with high titer p53 antibody showed spontaneous p53-specific CD8+ T cell responses following a single in vitro sensitization, significant p53-specific IFN-γ producing CD4+ T cells were detected in 6 patients. Surprisingly, similar levels of p53-specific CD4+ T cells but not CD8+ T cells were also detected in 5/10 seronegative cancer patients and 9/12 healthy donors. Importantly, p53-specific CD4+ T cells in healthy donors originated from a CD45RA− antigen-experienced T cell population and recognized naturally processed wild-type p53 protein. These results raise the possibility that p53-specific CD4+ T cells reflect abnormalities in p53 occurring in normal individuals and that they may play a role in processes of immunosurveillance or immunoregulation of p53-related neoplastic events.
Therapeutic immunization leading to cancer regression remains a significant challenge. Successful immunization requires activation of adaptive immunity, including tumor specific CD4 + T cells and CD8+ T cells. Generally speaking, the activation of T cells is compromised in patients with cancer due to immune suppression, loss of tumor antigen expression, and dysfunction of antigen presenting cells (APC). APC such as dendritic cells (DC) are key for the induction of adaptive anti-tumor immune responses. Recently, attention has focused on novel adjuvants that enhance DC function and their ability to prime T cells. Agonists that target toll-like receptors (TLR) are being used clinically either alone or in combination with tumor antigens and showing initial success both in terms of enhancing immune responses and eliciting anti-tumor activity. This review summarizes the application of these adjuvants to treat cancer and the potential for boosting responses in vivo.
Toll-like receptors; Cancer vaccines; Dendritic cells; Vaccine adjuvants
Due to the high homology between the LAGE-1 and NY-ESO-1 proteins,
we hypothesized that an anti-NY-ESO-1 vaccine might elicit LAGE-1
immunity and hence may be effective in multiple myeloma (MM) patients
with LAGE-1-positive/NY-ESO-1-negative tumors. Therefore,
we set out to evaluate LAGE-1 and NY-ESO-1 mRNA and protein expression
in MM patients in a bid to evaluate possible benefits of their homology
for immunotherapy. LAGE-1 (a and b isoforms)
and NY-ESO-1 mRNA expression was studied in 18
normal tissues and 50 bone marrow MM samples by RT-PCR. LAGE-1 and NY-ESO-1
protein expression was analyzed by immunohistochemistry (IHC) in
27 MM specimens using mAbs 219-510-23 and E978. Spontaneous serological
immune response against both antigens was analyzed by ELISA in sera
from 33 MM patients. LAGE-1 (a and b isoforms)
was positive in 42% and NY-ESO-1 in 26% of
the MM samples analyzed by RT-PCR. Both genes were found to be expressed
in 18% of the cases, while at least one of the genes was found
to be expressed in 50% of the cases. In LAGE-1 positive samples,
81% were positive for LAGE-1a and 19% were
positive for both LAGE-1a and -1b.
LAGE-1 and NY-ESO-1 protein expression could only be detected in
two cases by IHC and there was a clear strong spontaneous antibody
response to LAGE-1 and NY-ESO-1 in only one MM patient. In conclusion,
LAGE-1a and NY-ESO-1 homology cannot be easily exploited in an anti-NY-ESO-1
vaccine given the low frequency of protein expression detected by
IHC or serum analysis.
myeloma; CT antigens; RT-PCR; immunohistochemistry; ELISA
The type I melanoma antigen gene (MAGE) proteins CT7 (MAGE-C1) and MAGE-A3 are commonly expressed in multiple myeloma (MM), and their expression correlates with increased plasma cell proliferation and poor clinical outcome. They belong to the cancer-testis antigen (CTAg) group of tumor-associated proteins, some of which elicit spontaneous immune responses in cancer patients. CT7 and MAGE-A3 are promising antigenic targets for therapeutic tumor vaccines in myeloma; therefore, it is critical to determine if they are immunogenic in MM patients. We analyzed cellular and humoral immune responses against CTAgs in patients with plasma cell dyscrasias: MM, monoclonal gammopathy of undetermined significance (MGUS), and Waldenström’s macroglobulinemia (WM). Bone marrow lymphocytes from two of four untreated MM patients exhibited CT7-specific cellular immune responses as measured by an autologous cellular immunity assay, the first such immune response to CT7 to be reported in cancer patients. Sera from 24 patients were screened by ELISA for humoral immune responses to CTAgs. Two patients with MM demonstrated positive titers, one for MAGE-A1 and the other for SSX1. These data demonstrate that CTAgs, particularly CT7, are immunogenic in MM patients and merit further exploration as targets of immunological therapy in MM.
human; multiple myeloma; CT antigens; cellular immunity; humoral immunity