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author:("agnatic, S")
1.  The abscopal effect associated with a systemic anti-melanoma immune response 
Summary
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.
doi:10.1016/j.ijrobp.2012.03.017
PMCID: PMC3415596  PMID: 22560555
abscopal effect; melanoma; immunotherapy; cancer-testis antigen
4.  Future perspectives in melanoma research. Meeting report from the “Melanoma Bridge. Napoli, December 2nd-4th 2012” 
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.
doi:10.1186/1479-5876-11-137
PMCID: PMC3681569  PMID: 23731854
5.  A Pilot Study of Anti-CTLA4 Antibody Ipilimumab in Patients with Synovial Sarcoma 
Sarcoma  2013;2013:168145.
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.
doi:10.1155/2013/168145
PMCID: PMC3608267  PMID: 23554566
6.  A novel human-derived antibody against NY-ESO-1 improves the efficacy of chemotherapy 
Cancer Immunity  2013;13:3.
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.
PMCID: PMC3559191  PMID: 23390374
NY-ESO-1; antibody; chemotherapy
7.  MAGE-A3 is highly expressed in a subset of colorectal cancer patients 
Cancer Immunity  2012;12:16.
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.
PMCID: PMC3554221  PMID: 23390371
MAGE-A3; tumor expression; colorectal cancer; Cancer/Testis antigens
8.  Cancer classification using the Immunoscore: a worldwide task force 
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).
doi:10.1186/1479-5876-10-205
PMCID: PMC3554496  PMID: 23034130
9.  Immunologic Correlates of the Abscopal Effect in a Patient with Melanoma 
The New England Journal of Medicine  2012;366(10):925-931.
Summary
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.)
doi:10.1056/NEJMoa1112824
PMCID: PMC3345206  PMID: 22397654
10.  Cancer-testis antigen expression and immunogenicity in AL amyloidosis 
Blood Cancer Journal  2012;2(9):e90-.
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.
doi:10.1038/bcj.2012.32
PMCID: PMC3461704  PMID: 22983433
AL amyloidosis; cancer-testis antigens; stem cell transplantation
12.  NY-ESO-1 Cancer Testis Antigen Demonstrates High Immunogenicity in Triple Negative Breast Cancer 
PLoS ONE  2012;7(6):e38783.
Purpose
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.
Experimental Design
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.
Results
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).
Conclusion
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.
doi:10.1371/journal.pone.0038783
PMCID: PMC3386262  PMID: 22761704
13.  Split T-cell tolerance as a guide for the development of tumor antigen-specific immunotherapy 
Oncoimmunology  2012;1(3):405-407.
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.
doi:10.4161/onci.19310
PMCID: PMC3382850  PMID: 22737632
CD8 T lymphocytes; NY-ESO-1; Serum antibody; cancer vaccine; p53; tolerance; tumor antigen
14.  Treatment of Metastatic Melanoma with Autologous CD4+ T Cells against NY-ESO-1 
The New England Journal of Medicine  2008;358(25):2698-2703.
SUMMARY
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.
doi:10.1056/NEJMoa0800251
PMCID: PMC3277288  PMID: 18565862
15.  Split T Cell Tolerance against a Self/Tumor Antigen: Spontaneous CD4+ but Not CD8+ T Cell Responses against p53 in Cancer Patients and Healthy Donors 
PLoS ONE  2011;6(8):e23651.
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.
doi:10.1371/journal.pone.0023651
PMCID: PMC3155555  PMID: 21858191
16.  TLR AGONISTS: Are They Good Adjuvants? 
Cancer journal (Sudbury, Mass.)  2010;16(4):382-391.
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.
doi:10.1097/PPO.0b013e3181eaca65
PMCID: PMC2922045  PMID: 20693851
Toll-like receptors; Cancer vaccines; Dendritic cells; Vaccine adjuvants
17.  Evaluation of LAGE-1 and NY-ESO-1 expression in multiple myeloma patients to explore possible benefits of their homology for immunotherapy 
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.
PMCID: PMC3077292  PMID: 21247062
human; multiple myeloma; CT antigens; RT-PCR; immunohistochemistry; ELISA
18.  Cellular immune responses against CT7 (MAGE-C1) and humoral responses against other cancer-testis antigens in multiple myeloma patients 
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.
PMCID: PMC2926649  PMID: 20108890
human; multiple myeloma; CT antigens; cellular immunity; humoral immunity
20.  Inducing Efficient Cross-priming Using Antigen-coated Yeast Particles 
Summary
Saccharomyces cerevisiae stimulates dendritic cells (DCs) and represents a promising candidate for cancer vaccine development. Effective cross-presentation of antigen delivered to DCs is necessary for successful induction of cellular immunity. Here, we present a yeast-based vaccine approach that is independent of yeast’s ability to express the chosen antigen, which is instead produced separately and conjugated to the yeast cell wall. The conjugation method is site-specific (based on the SNAP-tag) and designed to facilitate antigen release in the DC phagosome and subsequent translocation for cross-presentation. We demonstrate that nonsite-specific chemical conjugation of the same protein hinders cross-presentation. Phagosomal antigen release was further expedited through the insertion of the invariant chain ectodomain as a linker, which is rapidly cleaved by Cathepsin S. The dose of delivered antigen was increased in several ways: by using yeast strains with higher surface amine densities, by using yeast hulls (cell wall fragments) instead of whole cells, and by conjugating multiple layers of antigen. The novel multilayer conjugation scheme takes advantage of Sfp phosphopantetheinyl transferase and remains site-specific; it enables the antigen dose to grow linearly with the number of layers. We show that whole yeast cells coated with 1 layer of the cancer-testis antigen NY-ESO-1 and yeast hulls bearing 3 layers were able to cross-prime naive CD8+ T cells in vitro, with the latter resulting in higher frequencies of antigen-specific cells after 10 days. This cross-presentation-efficient antigen conjugation scheme is not limited to yeast and can readily be applied toward the development of other particulate vaccines.
doi:10.1097/CJI.0b013e318181c87f
PMCID: PMC2820298  PMID: 18600183
cross-priming; cross-presentation; cancer vaccine; conjugation; yeast
21.  Cellular immune responses against CT7 (MAGE-C1) and humoral responses against other cancer-testis antigens in multiple myeloma patients 
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.
PMCID: PMC2926649  PMID: 20108890
human; multiple myeloma; CT antigens; cellular immunity; humoral immunity
22.  Correlation of clinical and immunological data in a metastatic melanoma patient with heterogeneous tumor responses to ipilimumab therapy 
Melanoma patients treated with anti-CTLA-4 have shown a range of anti-tumor responses. In this report, we describe the response of a single patient to anti-CTLA-4, with individual lesions disappearing, others stabilizing, and others progressing. These responses can be viewed as a clear manifestation of cancer immunoediting and its three phases of elimination, equilibrium and escape, with each tumor in this patient being at a discrete stage in the process. The patient's course and associated immunological monitoring and other laboratory data are presented in an immunogram, a way to visualize temporal associations between the multiple clinical and laboratory parameters.
PMCID: PMC2964016  PMID: 20052966
human; melanoma; ipilimumab; case report; immunogram; immunoediting
23.  Immunization of malignant melanoma patients with full-length NY-ESO-1 protein using Toll-like receptor 7 agonist imiquimod as vaccine adjuvant 
T cell-mediated immunity to microbes and to cancer can be enhanced by the activation of dendritic cells (DCs) via Toll-like receptors (TLRs). In this study, we evaluated the safety and feasibility of topical imiquimod, a TLR7 agonist, in a series of vaccinations (26) proteins,(27) and DNA, (28, 29) as well as in vaccines using recombinant Listeria(30) or DCs.(31) In humans, it was shown that topical imiquimod treatment may enhance the immunogenicity of a melanoma peptide vaccine when given with systemic FLT3 ligand. (32) In addition, injection of immature DCs into imiquimod pretreated skin lead to DC activation in situ and enhanced migratory capacity to draining lymph nodes in cancer patients. (33)
In this study, we test the safety and feasibility of imiquimod in a vaccine against the cancer/testis antigen NY-ESO-1, and evaluate the immunogenicity of the combination. NY-ESO-1 is detectable in approximately 30% of metastatic melanomas. (34-36) It is against the cancer/testis antigen NY-ESO-1 in patients with malignant melanoma. Recombinant, full-length NY-ESO-1 protein was administered intradermally into imiquimod pre-conditioned sites followed by additional topical applications of imiquimod. The regimen was very well-tolerated with only mild and transient local reactions and constitutional symptoms. Secondarily, we examined the systemic immune response induced by the imiquimod/NY-ESO-1 combination, and show that it elicited both humoral and cellular responses in a significant fraction of patients. Skin biopsies were assessed for imiquimod's in situ immunomodulatory effects. Compared with untreated skin, topical imiquimod induced dermal mononuclear cell infiltrates in all patients composed primarily of T cells, monocytes, macrophages, myeloid DCs and natural killer (NK) cells, and to a lesser extent plasmacytoid DCs. DC activation was evident. This study demonstrates the feasibility and excellent safety profile of a topically applied TLR7 agonist utilized as a vaccine adjuvant in cancer patients. Imiquimod's adjuvant effects require further evaluation and likely need optimization of parameters such as formulation, dose and timing relative to antigen exposure for maximal immunogenicity.
PMCID: PMC2583094  PMID: 18566444
Toll-like receptor; TLR7 agonist; imiquimod; cancer vaccine
24.  CTdatabase: a knowledge-base of high-throughput and curated data on cancer-testis antigens 
Nucleic Acids Research  2008;37(Database issue):D816-D819.
The potency of the immune response has still to be harnessed effectively to combat human cancers. However, the discovery of T-cell targets in melanomas and other tumors has raised the possibility that cancer vaccines can be used to induce a therapeutically effective immune response against cancer. The targets, cancer-testis (CT) antigens, are immunogenic proteins preferentially expressed in normal gametogenic tissues and different histological types of tumors. Therapeutic cancer vaccines directed against CT antigens are currently in late-stage clinical trials testing whether they can delay or prevent recurrence of lung cancer and melanoma following surgical removal of primary tumors. CT antigens constitute a large, but ill-defined, family of proteins that exhibit a remarkably restricted expression. Currently, there is a considerable amount of information about these proteins, but the data are scattered through the literature and in several bioinformatic databases. The database presented here, CTdatabase (http://www.cta.lncc.br), unifies this knowledge to facilitate both the mining of the existing deluge of data, and the identification of proteins alleged to be CT antigens, but that do not have their characteristic restricted expression pattern. CTdatabase is more than a repository of CT antigen data, since all the available information was carefully curated and annotated with most data being specifically processed for CT antigens and stored locally. Starting from a compilation of known CT antigens, CTdatabase provides basic information including gene names and aliases, RefSeq accession numbers, genomic location, known splicing variants, gene duplications and additional family members. Gene expression at the mRNA level in normal and tumor tissues has been collated from publicly available data obtained by several different technologies. Manually curated data related to mRNA and protein expression, and antigen-specific immune responses in cancer patients are also available, together with links to PubMed for relevant CT antigen articles.
doi:10.1093/nar/gkn673
PMCID: PMC2686577  PMID: 18838390
25.  PLAC1, a trophoblast-specific cell surface protein, is expressed in a range of human tumors and elicits spontaneous antibody responses 
Identification of genes that are upregulated in tumors, and whose normal expression excludes adult somatic tissues but includes germline and/or embryonic tissues, has resulted in a rich variety of cancer antigens that are attractive targets for cancer vaccine and other therapeutic approaches. In the present study, we extended this approach to include genes strongly and restrictively expressed in the placenta by mining publicly available SAGE and EST databases. We identified a number of genes with high expression in placenta and different cancer types but with relatively restricted expression in normal tissues. The gene with the most distinctive expression pattern was found to be PLAC1, which encodes a putative cell surface protein that is highly expressed in placenta, testis, cancer cell lines and lung tumors. Hence we have designated it CT92. We found by ELISA that PLAC1 is immunogenic in a subset of cancer patients and healthy women. Its physical and expression characteristics render it a potential target for both active and passive cancer immunotherapeutic strategies.
PMCID: PMC2935750  PMID: 17983203
human; tumor antigens; PLAC1; mRNA; tissue distribution; humoral immunity

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