mart-1-antigen and Neoplasms

Topics: Antigens, Neoplasm; Humans; Immunotherapy; Interleukin-2; Lymphocytes, Tumor-Infiltrating; MART-1 Antigen; Neoplasm Proteins; Neoplasms

To determine the ocular safety of CP-675,206 (Pfizer, New York, New York, USA), a fully human anti-cytotoxic T lymphocyte-associated antigen 4 monoclonal antibody in clinical trials of immunotherapy of metastatic melanoma.. Prospective, nonrandomized study of the eye and vision in phase I/II clinical trials of CP-675,206 in metastatic melanoma conducted at the University of California, Los Angeles.. Patients with regional or distant metastatic melanoma were enrolled in phase I/II clinical trials evaluating the safety and antitumor efficacy of CP-675,206 alone or in combination with melanoma antigen peptide-pulsed dendritic cell vaccines. Ophthalmic evaluation was performed at the onset of CP-675,206 immunotherapy (baseline evaluation), two months or more after the onset of CP-675,206 immunotherapy (end-study evaluation), and at two- to three-month intervals thereafter in patients who continued to receive CP-675,206 immunotherapy (poststudy evaluation). Baseline and end-study evaluations included comprehensive ophthalmic examination, psychophysical and electrophysiologic visual function assessment, fundus photography, fluorescein angiography, and visual function assessment.. Twenty patients with metastatic melanoma arising from the skin, mucosa, eye, or unknown site were evaluated. Systemic toxicity attributed to CP-675,206 included dermatologic manifestations, diarrhea, and autoimmune hepatitis with panhypopituitarism. A subset of patients receiving CP-675,206 demonstrated antitumor efficacy with partial response or complete response of metastatic melanoma. Comparison of ophthalmic baseline with end-study evaluations in all 20 patients and limited-term poststudy evaluations showed no adverse effect of CP-675,206 immunotherapy on the eye or vision.. In this study, CP-675,206 immunotherapy for metastatic melanoma did not adversely affect the eye or vision.

Topics: Abatacept; Adult; Aged; Aged, 80 and over; Antibodies, Blocking; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antigens, Neoplasm; Anus Neoplasms; Choroid Neoplasms; Drug Therapy, Combination; Electrooculography; Electroretinography; Female; Fluorescein Angiography; Humans; Immunoconjugates; Immunotherapy; Male; MART-1 Antigen; Melanoma; Middle Aged; Neoplasm Proteins; Neoplasms; Ocular Physiological Phenomena; Prospective Studies; Skin Neoplasms; Treatment Outcome; Vision, Ocular; Visual Acuity

Cytotoxic T lymphocyte-associated antigen 4 (CTLA4) blockade with CP-675,206, a fully human anti-CTLA4 monoclonal antibody, may break peripheral immunologic tolerance leading to effective immune responses to cancer in humans. A phase I trial was conducted to test the safety of CP-675,206.. Thirty-nine patients with solid malignancies (melanoma, n = 34; renal cell, n = 4; colon, n = 1) received an intravenous (IV) infusion of CP-675,206 at seven dose levels. The primary objective was to determine the maximum-tolerated dose and the recommended phase II dose.. Dose-limiting toxicities and autoimmune phenomena included diarrhea, dermatitis, vitiligo, panhypopituitarism and hyperthyroidism. Two patients experienced complete responses (maintained for 34+ and 25+ months), and there were two partial responses (26+ and 25+ months) among 29 patients with measurable melanoma. There have been no relapses thus far after objective response to therapy. Four other patients had stable disease at end of study evaluation (16, 7, 7, and 4 months). Additionally, five patients had extended periods without disease progression (36+, 35+, 26+, 24+, and 23+ months) after local treatment of progressive metastases. Longer systemic exposure to CP-675,206 achieved in higher dose cohorts predicted for a higher probability of response.. CP-675,206 can be administered safely to humans as a single IV dose up to 15 mg/kg, resulting in breaking of peripheral immune tolerance to self-tissues and antitumor activity in melanoma.

Topics: Adult; Aged; Antibodies, Blocking; Antibodies, Monoclonal; Antibodies, Neoplasm; Antigens, CD; Antigens, Differentiation; Antigens, Neoplasm; Autoimmune Diseases; Cancer Vaccines; Colonic Neoplasms; CTLA-4 Antigen; Female; Humans; Immune Tolerance; Immunotherapy; Infusions, Intravenous; Kidney Neoplasms; Male; MART-1 Antigen; Melanoma; Middle Aged; Neoplasm Proteins; Neoplasms; Regression Analysis; T-Lymphocyte Subsets; Treatment Outcome

Aging is associated with functional deficits in the naive T cell compartment, which compromise the generation of de novo immune responses against previously unencountered Ags. The mechanisms that underlie this phenomenon have nonetheless remained unclear. We found that naive CD8

Topics: Adult; Aged; Aged, 80 and over; Aging; Apoptosis; Cancer Vaccines; CD8-Positive T-Lymphocytes; Cell Division; COVID-19; Female; Fenofibrate; Glucose; HLA-A2 Antigen; Humans; Hypolipidemic Agents; Immunocompetence; Influenza, Human; Lipid Metabolism; Lymphocyte Activation; Male; MART-1 Antigen; Middle Aged; Neoplasms; Peptide Fragments; Rosiglitazone; Single-Blind Method; Vaccination; Viral Vaccines; Young Adult

Recruitment and activation of CD8 T cells occur through specific triggering of T cell receptor (TCR) by peptide-bound human leucocyte antigen (HLA) ligands. Within the generated trimeric TCR-peptide:HLA complex, the molecular binding affinities between peptide and HLA, and between TCR and peptide:HLA both impact T cell functional outcomes. However, how their individual and combined effects modulate immunogenicity and overall T cell responsiveness has not been investigated systematically. Here, we established two panels of human tumor peptide variants differing in their affinity to HLA. For precise characterization, we developed the "blue peptide assay", an upgraded cell-based approach to measure the peptide:HLA affinity. These peptide variants were then used to investigate the cross-reactivity of tumor antigen-specific CD8 T cell clonotypes derived from blood of cancer patients after vaccination with either the native or an affinity-optimized Melan-A/MART-1 epitope, or isolated from tumor infiltrated lymph nodes (TILNs). Vaccines containing the native tumor epitope generated T cells with better functionality, and superior cross-reactivity against potential low affinity escape epitopes, as compared to T cells induced by vaccines containing an HLA affinity-optimized epitope. Comparatively, Melan-A/MART-1-specific TILN cells displayed functional and cross-reactive profiles that were heterogeneous and clonotype-dependent. Finally, we took advantage of a collection of T cells expressing affinity-optimized NY-ESO-1-specific TCRs to interrogate the individual and combined impact of peptide:HLA and TCR-pHLA affinities on overall CD8 T cell responses. We found profound and distinct effects of both biophysical parameters, with additive contributions and absence of hierarchical dominance. Altogether, the biological impact of peptide:HLA and TCR-pHLA affinities on T cell responses was carefully dissected in two antigenic systems, frequently targeted in human cancer immunotherapy. Our technology and stepwise comparison open new insights into the rational design and selection of vaccine-associated tumor-specific epitopes and highlight the functional and cross-reactivity profiles that endow T cells with best tumor control capacity.

Topics: CD8-Positive T-Lymphocytes; Epitopes; Histocompatibility Antigens Class II; Humans; MART-1 Antigen; Neoplasms; Peptides; Receptors, Antigen, T-Cell

Nonocular melanocytic neoplasia is considered uncommon in cats yet is routinely encountered in diagnostic pathology and recognized to exhibit a wide variation in biological behavior. Accurate prediction of clinical outcomes is challenging with no widely recognized prognostic criteria. Signalment and tumor location were retrospectively evaluated in 324 cats diagnosed with nonocular melanocytic neoplasia. Histologic features were described in 141 neoplasms and outcome data were available in 79 cases. Immunohistochemistry using Melan-A, PNL-2, cyclooxygenase 2 (COX-2), and E-cadherin was performed in a subset (

Topics: Animals; Biomarkers, Tumor; Cat Diseases; Cats; Female; Immunohistochemistry; Male; MART-1 Antigen; Melanocytes; Mitosis; Necrosis; Neoplasm Grading; Neoplasms; Prognosis; Retrospective Studies; Sensitivity and Specificity

Peptide recognition through the MHC class I molecule by cytotoxic T lymphocytes (CTLs) leads to the killing of cancer cells. A potential challenge for T-cell immunotherapy is that dendritic cells (DCs) are exposed to the MHC class I-peptide complex for an insufficient amount of time. To improve tumour antigen presentation to T cells and thereby initiate a more effective T-cell response, we generated artificial antigen-presenting cells (aAPCs) by incubating human immature DCs (imDCs) with poly(lactic-co-glycolic) acid nanoparticles (PLGA-NPs) encapsulating tumour antigenic peptides, followed by maturation with lipopolysaccharide. Tumour antigen-specific CTLs were then induced using either peptide-loaded mature DCs (mDCs) or aAPCs, and their activities were analysed using both ELISpot and cytotoxicity assays. We found that the aAPCs induced significantly stronger tumour antigen-specific CTL responses than the controls, which included both mDCs and aAPCs loaded with empty nanoparticles. Moreover, frozen CTLs that were generated by exposure to aAPCs retained the capability to eradicate HLA-A2-positive tumour antigen-bearing cancer cells. These results indicated that aAPCs are superior to DCs when inducing the CTL response because the former are capable of continuously presenting tumour antigens to T cells in a sustained manner. The development of aAPCs with PLGA-NPs encapsulating tumour antigenic peptides is a promising approach for the generation of effective CTL responses in vitro and warrants further assessments in clinical trials.

Topics: Antigen Presentation; Cancer Vaccines; Cell Survival; Cytotoxicity, Immunologic; Delayed-Action Preparations; Dendritic Cells; Drug Compounding; Drug Liberation; Humans; Inhibitor of Apoptosis Proteins; Kinetics; Lactic Acid; Lipopolysaccharides; MART-1 Antigen; MCF-7 Cells; Nanoparticles; Neoplasms; Peptide Fragments; Polyglycolic Acid; Polylactic Acid-Polyglycolic Acid Copolymer; Solubility; Survivin; T-Lymphocytes, Cytotoxic

The aim of this study was to describe a method for analysing histological fragments derived from fine- needle aspirate biopsy (FNAB) of salivary gland tumours (SGTs), and to evaluate the use of immunohistochemistry (IHC) on them.. We reviewed all 509 FNAB pathology reports taken from SGTs at Helsinki University Hospital, Finland, between 1999 and 2009. In 51% of the cases (n = 209) "histo-fragments" had been obtained and 31 had been further analysed by IHC. Of these, 25 (81%) were available for review. We evaluated the benefit of IHC by relating its added value to the preoperative cytological diagnosis and its accuracy compared with the postoperative histological diagnosis.. Most of the samples analysed by IHC were assigned a malignant diagnosis, with 12 different types of malignancy represented. IHC was advantageous in 76% of the cases. In the 108 studies using IHC in this series, antibodies to 36 different antigens were used.. Analysis of histo-fragments in FNABs using IHC can be valuable in specific differential diagnostics and raises diagnostic accuracy in SGTs.

Topics: Adenolymphoma; Adenoma, Pleomorphic; Biomarkers, Tumor; Biopsy, Fine-Needle; Diagnosis, Differential; DNA-Binding Proteins; Gene Expression; Humans; Immunohistochemistry; MART-1 Antigen; Neoplasms; Retrospective Studies; Salivary Gland Neoplasms; Salivary Glands; Sensitivity and Specificity; Transcription Factors

Dendritic cell-derived exosomes (DEX) comprise an efficient stimulator of T cells. However, the production of sufficient DEX remains a barrier to their broad applicability in immunotherapeutic approaches. In previous studies, genetically engineered K562 have been used to generate artificial antigen presenting cells (AAPC). Here, we isolated exosomes from K562 cells (referred to as CoEX-A2s) engineered to express human leukocyte antigen (HLA)-A2 and costimulatory molecules such as CD80, CD83, and 41BBL. CoEX-A2s were capable of stimulating antigen-specific CD8 T cells both directly and indirectly via CoEX-A2 cross-dressed cells. Notably, CoEX-A2s also generated similar levels of HCMV pp65-specific and MART1-specific CD8 T cells as DEX in vitro. The results suggest that these novel exosomes may provide a crucial reagent for generating antigen-specific CD8 T cells for adoptive cell therapies against viral infection and tumors.

Topics: 4-1BB Ligand; Antigens, CD; B7-1 Antigen; CD8-Positive T-Lymphocytes; CD83 Antigen; Cross-Priming; Dendritic Cells; Exosomes; Genetic Engineering; HLA-A2 Antigen; Humans; Immunoglobulins; Immunotherapy, Adoptive; K562 Cells; Lymphocyte Activation; MART-1 Antigen; Membrane Glycoproteins; Neoplasms; Phosphoproteins; Viral Matrix Proteins; Virus Diseases

Human T cells expressing γδ T cell receptor have a potential to show antigen-presenting cell-like phenotype and function upon their activation. However, the mechanisms that underlie the alterations in human γδ T cells remain largely unclear. In this study, we have investigated the molecular characteristics of human γδ T cells related to their acquisition of antigen-presenting capacity in comparison with activated αβ T cells. We found that activated γδ but not αβ T cells upregulated cell surface expression of a scavenger receptor, CD36, which seemed to be mediated by signaling through mitogen-activated protein kinase and/or NF-κB pathways. Confocal microscopical analysis revealed that activated γδ T cells can phagocytose protein antigens. Activated γδ T cells could induce tumor antigen-specific CD8(+) T cells using both apoptotic and live tumor cells as antigen resources. Furthermore, we detected that C/EBPα, a critical transcription factor for the development of myeloid-lineage cells, is expressed much higher in γδ T cells than in αβ T cells. These results unveiled the molecular mechanisms for the elicitation of antigen-presenting functions in γδ T cells and would also help designing new approaches for γδ T cell-mediated human cancer immunotherapy.

Topics: Antigen Presentation; Antigens, Neoplasm; CCAAT-Enhancer-Binding Proteins; CD36 Antigens; CD8-Positive T-Lymphocytes; Cell Differentiation; Cell Line, Tumor; Cell Lineage; Cytotoxicity, Immunologic; Heterocyclic Compounds, 3-Ring; Humans; Imidazoles; Immunotherapy; Lymphocyte Activation; MART-1 Antigen; Myeloid Cells; Neoplasms; NF-kappa B; p38 Mitogen-Activated Protein Kinases; Phagocytosis; Pyridines; Receptors, Antigen, T-Cell, gamma-delta; Signal Transduction; T-Lymphocytes; Up-Regulation

Human pluripotent stem cells (hPSCs) provide a promising platform to produce dendritic cell (DC) vaccine. To streamline the production process, we investigated a unique antigen-loading strategy that suits this novel platform. Specifically, we stably modified hPSCs using tumour antigen genes in the form of a full-length tumour antigen gene or an artificial tumour antigen epitope-coding minigene. Such antigenically modified hPSCs were able to differentiate into tumour antigen-presenting DCs. Without conventional antigen-loading, DCs derived from the minigene-modified hPSCs were ready to prime a tumour antigen-specific T cell response and further expand these specific T cells in restimulation processes. These expanded tumour antigen-specific T cells were potent effectors with central memory or effector memory phenotype. Thus, we demonstrated that immunocompetent tumour antigen-loaded DCs can be directly generated from antigenically modified hPSCs. Using such strategy, we can completely eliminate the conventional antigen-loading step and significantly simplify the production of DC vaccine from hPSCs.

Topics: Antigens, Neoplasm; Cancer Vaccines; CD8-Positive T-Lymphocytes; Cell Line; Dendritic Cells; Epitopes; Genes, Reporter; Genetic Vectors; Humans; Immunocompetence; MART-1 Antigen; Neoplasms; Pluripotent Stem Cells; Response Elements

The generation of effector CD8(+) T cells with lytic capacity is crucial for tumor control. Dendritic cells (DCs) provide important signals to promote naive CD8(+) T cell priming and activation of effector T cells. Here, we report that the Notch pathway has an important role in both these processes in human CD8(+) T cells. Activated monocyte-derived DCs express Notch ligands Jagged1 and Delta-like4, whereas naive CD8(+) T cells express Notch2. The role for Notch signaling in CD8(+) T cell priming was determined using an ex-vivo model system in which tumor antigen-specific primary CD8(+) T cell responses were measured. Inhibition of Notch using γ-secretase inhibitors or soluble Delta-like4-Fc during activation reduced expansion of antigen-specific CD8(+) T cells, which was mirrored by decreased frequencies of interferon (IFN)γ-, tumor necrosis factor-α-, and granzymeB-producing CD8(+) T cells. Moreover, T cells primed when Notch signaling was prevented are functionally low-avidity T cells. In addition, Notch partially regulates established effector T cell function. Activation-induced Notch signaling is needed for IFNγ release but not for cytolytic activity. These data indicate that Notch signaling controls human CD8(+) T cell priming and also influences effector T cell functions. This may provide important information for designing new immunotherapies for treatment of cancer.

Topics: Antigen Presentation; CD8-Positive T-Lymphocytes; Cell Communication; Cells, Cultured; Dendritic Cells; Humans; Interferon-gamma; Lymphocyte Activation; MART-1 Antigen; Monocytes; Neoplasms; Receptor, Notch1; Receptor, Notch2; Signal Transduction

Indoleamine 2,3-dioxygenase (IDO) is an immunoregulatory enzyme that is implicated in suppressing T-cell immunity in normal and pathologic settings. Here, we describe that spontaneous cytotoxic T-cell reactivity against IDO exists not only in patients with cancer but also in healthy persons. We show that the presence of such IDO-specific CD8(+) T cells boosted T-cell immunity against viral or tumor-associated antigens by eliminating IDO(+) suppressive cells. This had profound effects on the balance between interleukin-17 (IL-17)-producing CD4(+) T cells and regulatory T cells. Furthermore, this caused an increase in the production of the proinflammatory cytokines IL-6 and tumor necrosis factor-α while decreasing the IL-10 production. Finally, the addition of IDO-inducing agents (ie, the TLR9 ligand cytosine-phosphate-guanosine, soluble cytotoxic T lymphocyte-associated antigen 4, or interferon γ) induced IDO-specific T cells among peripheral blood mononuclear cells from patients with cancer as well as healthy donors. In the clinical setting, IDO may serve as an important and widely applicable target for immunotherapeutic strategies in which IDO plays a significant regulatory role. We describe for the first time effector T cells with a general regulatory function that may play a vital role for the mounting or maintaining of an effective adaptive immune response. We suggest terming such effector T cells "supporter T cells."

Topics: Adaptive Immunity; Antigens, Viral; Base Sequence; Cell Line, Tumor; Cytomegalovirus; DNA Primers; Down-Regulation; Female; Humans; In Vitro Techniques; Indoleamine-Pyrrole 2,3,-Dioxygenase; Interleukin-17; Lymphocyte Activation; Male; MART-1 Antigen; Neoplasms; RNA, Small Interfering; T-Lymphocyte Subsets; T-Lymphocytes, Cytotoxic; T-Lymphocytes, Regulatory

Dendritic cell (DC)-based cancer immunotherapy using tumor homogenate has been evaluated. In all previously reported cases, DCs have been pulsed with a soluble fraction (lysate) of the tumor homogenate. The aim of this study was the evaluation of DCs pulsed with solubilized insoluble fraction of tumor cells.. Solubilized recombinant murine TRP-2 and solubilized-insoluble fraction of B16 melanoma was prepared by a novel method using nucleotides. Bone marrow-derived DCs were electroloaded with the solubilized proteins.. Cytotoxic T lymphocytes were elicited in the splenocytes of C57BL/6 mice immunized with electroloaded DCs with solubilized rTRP-2. CD8(+) T-cells derived from immunized mice with electroloaded DCs using the solubilized insoluble fraction of B16 melanoma had specific killing activity. The effects were augmented when DCs were electroloaded with both the soluble and insoluble fractions of B16 homogenate.. Insoluble fraction of tumor cells is a useful material for cancer immunotherapy.

Topics: Animals; Antigens, Neoplasm; Biochemistry; Cell Extracts; Cell Line, Tumor; Cytotoxicity, Immunologic; Dendritic Cells; Humans; Immunization; Intramolecular Oxidoreductases; MART-1 Antigen; Mice; Mice, Inbred C57BL; Neoplasm Proteins; Neoplasms; Nucleotides; Recombinant Proteins; Solubility; Spleen; Subcellular Fractions; T-Lymphocytes, Cytotoxic

T cells engineered to express TCRs specific for tumor Ags can drive cancer regression. The first TCRs used in cancer gene therapy, DMF4 and DMF5, recognize two structurally distinct peptide epitopes of the melanoma-associated MART-1/Melan-A protein, both presented by the class I MHC protein HLA-A*0201. To help understand the mechanisms of TCR cross-reactivity and provide a foundation for the further development of immunotherapy, we determined the crystallographic structures of DMF4 and DMF5 in complex with both of the MART-1/Melan-A epitopes. The two TCRs use different mechanisms to accommodate the two ligands. Although DMF4 binds the two with a different orientation, altering its position over the peptide/MHC, DMF5 binds them both identically. The simpler mode of cross-reactivity by DMF5 is associated with higher affinity toward both ligands, consistent with the superior functional avidity of DMF5. More generally, the observation of two diverging mechanisms of cross-reactivity with the same Ags and the finding that TCR-binding orientation can be determined by peptide alone extend our understanding of the mechanisms underlying TCR cross-reactivity.

Topics: Animals; Cross Reactions; Crystallography, X-Ray; Genetic Therapy; HLA-A2 Antigen; Humans; Immunotherapy; MART-1 Antigen; Neoplasms; Protein Binding; Protein Structure, Quaternary; Protein Structure, Secondary; Receptors, Antigen, T-Cell; T-Lymphocytes

Attenuating coinhibitory molecules for the treatment of cancer is gaining a great deal of attention as a strategy for immunotherapy. The B and T lymphocyte attenuator (BTLA, CD272) is a novel coinhibitory molecule structurally and functionally related to CTLA-4 and PD-1. A study in this issue of the JCI by Derré et al. reveals that BTLA is expressed on virus-specific human CD8+ T cells but is progressively downregulated after their differentiation from a naive to effector phenotype (see the related article beginning on page 157). Surprisingly, tumor-specific human CD8+ T cells continue to express BTLA even after their differentiation to an effector phenotype. Remarkably, vaccination of melanoma patients with CpG led to BTLA downregulation on tumor-specific human CD8+ T cells, concomitant with restoration of their functionality. We discuss these findings in the context of the expanding field of cosignaling molecules and their implications for T cell-based therapies for cancer.

Topics: Antigens, CD; Antigens, Neoplasm; CTLA-4 Antigen; GPI-Linked Proteins; Humans; Immunotherapy; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Oligodeoxyribonucleotides; Receptors, Immunologic; T-Lymphocytes

Adoptive cell therapy with ex vivo expanded autologous antitumor cytotoxic T lymphocytes represents an important therapeutic option as an anticancer strategy. In order to identify a reliable method for producing adequate amounts of functional antitumor cytotoxic T lymphocytes with a potentially long in vivo lifespan, we tested the T-cell expansion efficiency of a new artificial antigen-presenting cell-based system.. Our artificial antigen-presenting cells were generated with activating (anti-CD3), co-stimulating (anti-CD28) and adhesion (anti-LFA-1) biotinylated monoclonal antibodies preclustered in microdomains held on a liposome scaffold by neutravidin rafts. The co-localization of T-cell ligands in microdomains and the targeting of an adhesion protein, increasing the efficiency of immunological synapse formation, represent the novelties of our system. The activity of our artificial antigen-presenting cells was compared with that of anti-CD3/-CD28 coated immunomagnetic microbeads and immobilized anti-CD3 monoclonal antibody (OKT3 clone), the only two commercially available artificial systems.. Our artificial antigen-presenting cells expanded both polyclonal T cells and MART-1-specific CD8(+) T cells in a more efficient manner than the other systems. Stimulation with artificial antigen-presenting cells allows for the generation of viable T cells displaying an immunophenotype consistent with in vivo potential for persistence, without increasing the frequency of regulatory T cells. The starting specificity of anti MART-1 CD8(+) T cells was preserved after stimulation with artificial antigen-presenting cells and it was statistically greater when compared to the activity of the same cells expanded with the other systems. Finally, our artificial antigen-presenting cells proved to be suitable for large-scale application, minimizing the volume and the costs of T-cell expansion.. Our artificial antigen-presenting cells might represent an efficient tool to rapidly obtain a sufficient number of functional T cells for adoptive immunotherapy in patients with cancer.

Topics: Antibodies, Monoclonal; Antigen-Presenting Cells; Antigens, Neoplasm; CD28 Antigens; CD3 Complex; Cell Differentiation; Cells, Cultured; Humans; Immunophenotyping; Lymphocyte Function-Associated Antigen-1; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Phenotype; T-Lymphocytes

Human cancer vaccines are often prepared with altered "analog" or "heteroclitic" antigens that have been optimized for HLA class I binding, resulting in enhanced immunogenicity. Here, we take advantage of CpG oligodeoxynucleotides as powerful vaccine adjuvants and demonstrate the induction of high T cell frequencies in melanoma patients, despite the use of natural (unmodified) tumor antigenic peptide. Compared with vaccination with analog peptide, natural peptide induced T cell frequencies that were approximately twofold lower. However, T cells showed superior tumor reactivity because of (i) increased functional avidity for natural antigen and (ii) enhancement of T cell activation and effector function. Thus, novel vaccine formulations comprising potent immune stimulators may allow to circumvent the need for modified antigens and can induce highly functional T cells with precise antigen specificity.

Topics: Amino Acid Sequence; Antigens, Neoplasm; Autoantigens; Cancer Vaccines; CD8-Positive T-Lymphocytes; Clone Cells; Epitopes; Granzymes; Humans; Interferon-gamma; Lymphocyte Activation; MART-1 Antigen; Molecular Sequence Data; Neoplasm Proteins; Neoplasms; Peptides; Perforin; Vaccination

There is a need for new technologies to study tissue-based biomarkers. The current gold standard, immunohistochemistry, is compromised by variability in tissue processing and observer bias. Reverse transcription-PCR (RT-PCR), immunocytochemistry, and reverse-phase lysate microarrays (RPM) are promising alternative technologies but have not yet been validated, or correlated, on the same patient-derived tissues. Furthermore, RPM is currently limited by time-consuming microdissection and low amounts of evaluable protein lysates.. Metastatic melanoma was surgically excised from 30 patients and macroscopically dissected from surrounding stroma. Each specimen was processed by formalin-fixation (immunohistochemistry), cytospin (immunocytochemistry), or disaggreagation and enrichment (RT-PCR and RPM). The latter protocol uses immunochromatography to remove hematopoetic-derived cells, thus enriching for melanoma cells. Each sample was measured for the expression of gp100 or MART-1 normalized to actin.. Immunochromatography coupled with RPM (I-RPM) is reproducible (r >/= 0.70) and, for gp100, correlates strongly with immunohistochemistry and immunocytochemistry (r = 0.78 and 0.76, respectively) and moderately with transcript levels, measured by RT-PCR (r = 0.61). In contrast, for MART-1, I-RPM correlates strongly with transcript level (r = 0.78) but only moderately strong correlations are noted with immunohistochemistry and immunocytochemistry (r = 0.64 and 0.59, respectively). In general, transcript levels show only moderately strong correlations with immunohistochemistry and immunocytochemistry (r = 0.41-0.64).. I-RPM is a promising technology for quantitative grading of tissue biomarkers; however, antigen-dependent correlations are noted.

Topics: Antigens, Neoplasm; Biomarkers, Tumor; Cell-Free System; Gene Expression Regulation, Neoplastic; gp100 Melanoma Antigen; Humans; Immunohistochemistry; MART-1 Antigen; Melanoma; Membrane Glycoproteins; Neoplasm Proteins; Neoplasms; Reproducibility of Results; Reverse Transcriptase Polymerase Chain Reaction; Skin Neoplasms

Appropriate presentation of tumor-associated antigens (TAA) by antigen-presenting cells (APC) is required for the development of clinically relevant antitumor T-cell responses. One common approach, which uses APC pulsed with synthetic peptides, can sometimes generate ineffective immune responses. This failure may, in part, be attributed to the formation of HLA/synthetic pulsed peptide complexes that possess different conformations compared with those of endogenously presented peptides. In addition, endogenous peptides may undergo post-translational modifications, which do not occur with synthetic peptides. Because our goal is to induce immunity that can recognize TAA that are endogenously presented by tumors, we designed an APC that would not only express the required immunoaccessory molecules but also naturally process and present target antigenic peptides. In this study, we generated an artificial APC (aAPC) that can endogenously present any chosen HLA-A*0201 (A2)-restricted peptide by processing a fusion protein that contains a unique "LTK" sequence linked to the antigenic peptide. Proteasome-dependent processing is so effective that the presented peptide can be directly eluted from the cell surface and identified by biochemical methods. Furthermore, we found that aAPC, engineered to endogenously present peptide derived from the melanoma antigen MART1, can be used to prime and expand antitumor CTL that target MART1-expressing tumor cells in a HLA-A2-restricted manner. Our engineered aAPC could serve as an "off-the-shelf" APC designed to constitutively express class I-restricted TAA peptides and could be used to generate effective T-cell responses to treat human disease.

Topics: Antigen Presentation; Antigen-Presenting Cells; Antigens, Neoplasm; HLA-A Antigens; HLA-A2 Antigen; Humans; Immunotherapy; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Peptide Fragments; Pregnancy Proteins; T-Lymphocytes, Cytotoxic

Recombinant poxviruses expressing immunomodulatory molecules together with specific antigens represent powerful vaccines for cancer immunotherapy. Recently, we and others have demonstrated, in vitro and in vivo, that coexpression of CD80 and CD86 costimulatory molecules enhances the immunogenic capacity of a recombinant vaccinia virus (rVV) encoding different tumor-associated antigens. To further investigate the capacity of these vectors to provide ligands for different costimulatory pathways relevant in the generation of T cell responses, we constructed a recombinant virus (rVV) expressing CD40 ligand or CD154 (CD154rVV). Upon binding the CD40 receptor expressed on antigen presenting cells (APC), this molecule, physiologically expressed on activated CD4+ T cells, increases their antigen presentation and immunostimulatory capacities. Therefore, we evaluated the effects of CD154rVV infection on APC activation and its consequences on T cell stimulation. CD154rVV infection of autologous fibroblasts, monocytes, or iDC promoted the expression of a number of cytokines, including GM-CSF, TNF-alpha, and IL-15 in iDC. Most importantly, IL-12 p40 gene expression and protein secretion were induced by CD154rVV but not by wild-type VV (WT VV) in either CD14+ cells or iDC, and these effects could be blocked by anti-CD40 monoclonal antibodies. Furthermore, phenotypic characterization of CD154rVV infected iDC revealed enhanced expression of CD83 and CD86 surface markers as compared with wild-type vaccinia virus infection. As expected, VV infection triggered cytokines gene expression in cultures including APC and T cells from VV immune donors. However, cytokine genes typically expressed by T cell receptor triggered T cells such as those encoding IL-2 and IFN-gamma, or T cell proliferation, were detectable to a significantly higher extent in CD154rVV infected cultures, as compared with WT VV. Activation of specific CD8+ T cells was then investigated using MART-1/Melan-A(27-35) epitope as the model of tumor-associated antigen (TAA). In the presence of CD154rVV activated APCs, significantly higher numbers of specific cytotoxic CD8+ T cells were detected, as compared with cultures performed in the presence of WT VV or in the absence of virus. Taken together, these data indicate that functional CD154 expression from rVV infected cells promotes APC activation, thereby enhancing antigen-specific T cell generation. Such a recombinant vector might help bypass the requirement for a

Topics: Animals; Antibodies, Monoclonal; Antigen-Presenting Cells; Antigens, Neoplasm; CD4-Positive T-Lymphocytes; CD40 Antigens; CD40 Ligand; CD8-Positive T-Lymphocytes; Cell Line; Chlorocebus aethiops; Cytokines; Cytotoxicity Tests, Immunologic; DNA Primers; Flow Cytometry; Genetic Vectors; Immunity, Cellular; Immunotherapy; Interleukin-12; Interleukin-12 Subunit p40; Ligands; Lymphocyte Activation; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Protein Subunits; Reverse Transcriptase Polymerase Chain Reaction; Vaccinia virus

Several recent reports have described the detection of circulating, cancer-related RNA molecules in serum or plasma from cancer patients, but little is known about the biology of this extracellular RNA. We aimed to determine how RNA is protected against degradation in serum, to optimize RNA isolation from large volumes of serum, and to test our optimized assays for serum-based cancer detection.. We used quantitative reverse transcription-PCR (QRT-PCR) analysis to investigate the isolation and biology of extracellular plasma RNA. We then examined the presence of amplifiable RNA transcripts in plasma and serum from controls and from patients with esophageal cancer and malignant melanoma.. We found that extracellular RNA in plasma is highly degraded and can be isolated most efficiently by guanidinium-phenol extraction followed by precipitation. Extracellular RNA is stable in serum for up to 3 h but is destroyed immediately by addition of detergents. Extracellular RNA can be captured on 0.2 microm filters, allowing concentration of RNA from several milliliters of plasma. When we concentrated RNA from up to 4 mL of serum, detection of cancer-related transcripts in serum from cancer patients and controls was infrequent and inconsistent.. Extracellular RNA is most likely protected within protein or lipid vesicles, possibly apoptotic bodies, which can be disrupted by detergents. Despite optimizing many aspects of plasma RNA detection, we were unable to reproducibly detect cancer-related transcripts. Our data suggest that measurement of circulating RNA may not be a good approach to early cancer diagnosis.

Topics: Animals; Antigens, Neoplasm; Centrifugation; Esophageal Neoplasms; Humans; Intermediate Filament Proteins; Keratin-20; MART-1 Antigen; Melanoma; Mice; Monophenol Monooxygenase; Neoplasm Proteins; Neoplasms; Plasma; Polymerase Chain Reaction; Reproducibility of Results; Ribonucleases; RNA, Messenger; RNA, Neoplasm; Sensitivity and Specificity

Common tumor vaccination strategies utilizing peptide-pulsed dendritic cells (DC) are limited to targeting antigens with known epitopes in patients expressing a defined restricting allele and can result in the preferential induction of low-avidity T cells that fail to recognize tumor cells. The use of dendritic cells transfected with RNA encoding tumor antigen offers the prospect of antigen-specific immunization without requiring prior knowledge of the immunogenic epitope or restricting allele, since epitopes from the translated protein are processed by the endogenous antigen-presentation machinery. However, its use in vaccine studies has been limited by low RNA transfection efficiency and the use of immature DC as recipient cells. In this study, we report an RNA transfection strategy that routinely achieves expression in 40-50% of mature DC, which are better stimulator cells. Such RNA-transfected mature DC exhibited a prolonged duration of presentation of immunogenic epitopes compared to peptide-pulsed DC, induced greater frequencies of tumor antigen-specific CTL, and generated a CTL population that exhibited higher target avidity and increased tumor lytic capacity. These studies provide compelling in vitro data supporting the evaluation of RNA-transfected mature DC in vaccination protocols as a means to overcome several obstacles to generating anti-tumor responses in vivo.

Topics: Antigens, Neoplasm; Cell Line; Dendritic Cells; Epitopes; Humans; Lymphocyte Activation; MART-1 Antigen; Neoplasm Proteins; Neoplasms; RNA, Neoplasm; T-Lymphocytes, Cytotoxic; Transfection; Vaccination

The production of cytotoxic T cells with specificity for cancer cells is a rapidly evolving branch of cancer therapeutics. A variety of approaches aim to amplify anti-tumour cytotoxic T cell responses using purified peptides, tumour cell lysates or recombinant HLA/peptide complexes in differing antigen presenting systems. Using a two-step biotin-streptavidin antibody targeting system, recombinant HLA-class I/peptide complexes were attached to the surface of B cells via the anti-CD20 B9E9-scFvSA antibody-streptavidin fusion protein. Flow cytometry with a conformation dependant monoclonal antibody to HLA class I indicated that targeted HLA-class I/peptide complexes remain on the surface of B cells in culture for periods in excess of 72 h. PBMCs were stimulated in vitro for 8-14 days using the autologous B cells as antigen presenting cells. Following a single cycle of stimulation specific cytotoxic T cell responses to targeted HLA-A2 complexes containing the M1, BMLF1 and Melan A peptides could be demonstrated by tetramer staining and Cr release assays. With the HLA-A2/BMLF1 complex up to 2.99% of CD8+ve cells were tetramer positive producing 20% lysis (E : T 10 : 1) of CIR-A2 target cells in an in vitro cytotoxicity assay compared to baseline levels of 0.09% tetramer +ve and 2% lysis in the unstimulated population. PBMCs from a healthy donor treated with two cycles of stimulations with targeted HLA-A2/Melan A complexes, demonstrated expansion of the melanA tetramer +ve population from 0.03% to 1.4% producing 15% lysis of Melan A pulsed target cells. With further consideration to the key variables of HLA/peptide complex density, the ratio of stimulator to effector cells and optimum cytokine support, this system should offer an easy and effective method for the in vitro amplification of specific cytotoxic T cell responses and warrants development for the in vivo induction of cytotoxic T cell responses in cancer therapy.

Topics: Antibodies; Antibody Specificity; Antigens, Neoplasm; B-Lymphocytes; Flow Cytometry; HLA-A2 Antigen; Humans; MART-1 Antigen; Melanoma; Neoplasm Proteins; Neoplasms; T-Lymphocytes, Cytotoxic; Time Factors; Tumor Cells, Cultured; Viruses

Topics: Antigens, Neoplasm; HLA-A2 Antigen; Humans; Immunotherapy; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Peptides; Receptors, Antigen, T-Cell; T-Lymphocytes, Cytotoxic

Peptide-based vaccines are currently being tested for their ability to induce or augment tumor antigen (Ag)-specific CD8+ T-cell responses in cancer patients. Here we report that the frequency of circulating CD8+ T cells directed against the Melan-A/MART-1 Ag increased >20-fold in an HLA-A2 melanoma patient immunized repeatedly with the corresponding antigenic peptide, as assessed by staining with HLA-A2/peptide tetramers. Multiparameter flow cytometric analysis demonstrated that the increase in total Melan-A-specific cell number was accompanied by a marked increase in the proportion of the cells that expressed an activated/memory surface phenotype. As assessed by ELISPOT assays and intracellular staining, the absolute number of Melan-A-specific cells able to secrete IFN-gamma increased >50-fold upon vaccination. When tested directly after cell sorting on the basis of tetramer staining, Melan-A-specific cells were weakly cytolytic but became highly active after in vitro restimulation. Altogether, these results indicate that large numbers of functionally active tumor Ag-specific CD8+ T cells can be obtained and maintained at high levels after in vivo activation by repeated peptide-based vaccination.

Topics: Antibodies, Monoclonal; Antigens, Neoplasm; Cancer Vaccines; CD8-Positive T-Lymphocytes; Cell Division; Flow Cytometry; Granzymes; Humans; Interferon-gamma; Lymphocytes; MART-1 Antigen; Melanoma; Neoplasm Proteins; Neoplasms; Peptides; Phenotype; Serine Endopeptidases; Time Factors

Tumor antigens that might serve as potential targets for adoptive T-cell therapy have been defined in different tumor entities, especially in malignant melanoma. To generate conditions to induce primary T-cell responses against different HLA-A*0201-restricted melanoma peptides and to allow further expansion of peptide-specific T cells for adoptive transfer, CD8+-purified T cells from healthy donors were stimulated with Melan-A-pulsed autologous dendritic cells. Dendritic cells were generated in vitro from monocytes with granulocyte macrophage colony-stimulating factor, interleukin-4, and transforming growth factor-beta1. After 3-4 weekly stimulation cycles with Melan-A-pulsed DCs, we were able to induce a strong peptide-specific CTL response in vitro. MHC-peptide tetramer staining revealed a frequency of up to 3.5% CD8+/Melan-A+ T cells. Additional antigen-independent expansion with anti-CD3/anti-CD28 monoclonal antibodies together with interleukin-2 gave rise to 600-fold expansion of CD8+ CTLs that maintained Melan-A specificity and were able to efficiently lyse Melan-A-expressing melanoma cells. To enrich antigen-specific T cells in vitro, we used a recently established technology for analysis and sorting of live cells according to secreted cytokines. In the present study, we demonstrated that Melan-A-specific T cells can be purified by magnetic separation according to secreted IFN-gamma. These cells revealed a very potent monospecific CTL response, even at low E:T ratios, against Melan-A-pulsed and Melan-A-expressing target cells. Altogether, our study demonstrated that we have developed an efficient method for generating large numbers of peptide-specific T cells in vitro that may be used for adoptive T-cell transfer in tumor immunotherapy.

Topics: Adoptive Transfer; Amino Acid Sequence; Antigens, Neoplasm; CD8 Antigens; Clone Cells; Dendritic Cells; HLA-A Antigens; Humans; Immunotherapy; Interferon-gamma; Leukocytes, Mononuclear; MART-1 Antigen; Neoplasm Proteins; Neoplasms; Protein Binding; T-Lymphocytes, Cytotoxic; Tumor Cells, Cultured

The functional characteristics of CD8+ T cells specific for melanoma antigens (MAs) have often been defined after in vitro culture using nonprofessional antigen-presenting cells. We have examined CD8+ T-cell immunity to MAs and a viral antigen (influenza) in uncultured T cells of healthy donors and melanoma patients using autologous, mature, monocyte-derived dendritic cells (DCs) pulsed with peptide antigens and viral vectors. Antigen-specific IFN-gamma-producing T cells reactive with HLA-A*0201-restricted peptides from four melanoma antigens (MelanA/MART-1, MAGE-3, tyrosinase, and gp100) were detected only at low frequencies (<30 per 2 x 10(5) peripheral blood mononuclear cells for each of the MAs) from HLA-A2.1-positive healthy donors (n = 12) and patients with stages III/IV melanoma (n = 8). Detection of MA-specific, but not influenza matrix peptide (Flu-MP)-specific, T cells required a high concentration (10 microg/ml) of the peptide in this assay. Furthermore, these T cells did not recognize endogenously processed antigen on tumor cell lines or cells infected with viral vectors capable of expressing MAs. The use of autologous, mature DCs led to a significant increase in the number of Flu-MP, but not MA-specific, T cells in 16-h ELISPOT assays for both melanoma patients and healthy donors. In 1-week cocultures with DCs pulsed with 10 microg/ml peptide, MelanA/MART-1-specific T cells did not readily proliferate or differentiate into lytic effectors, in contrast to strong influenza-specific lytic responses. Therefore, despite distinct memory responses to influenza antigens, melanoma patients and healthy controls have a paucity of MA-reactive memory T cells, failing to rapidly generate IFN-gamma-secreting lytic effectors in short-term assays, even when stimulated by DCs.

Topics: Antigens; Antigens, Neoplasm; CD8-Positive T-Lymphocytes; Coculture Techniques; Dendritic Cells; gp100 Melanoma Antigen; HLA-A Antigens; Humans; Immunologic Memory; Interferon-gamma; Leukocytes, Mononuclear; MART-1 Antigen; Melanoma; Membrane Glycoproteins; Monophenol Monooxygenase; Neoplasm Proteins; Neoplasms; Peptides; T-Lymphocytes; Time Factors; Tumor Cells, Cultured

Immunization with tumor-associated antigen pulsed dendritic cells (DC) has been shown to elicit both protective and therapeutic antitumor immunity in a variety of animal models and is currently being investigated for the treatment of cancer patients in clinical trials. In this study we show that DC can be generated from peripheral blood mononuclear cells of healthy donors as well as breast and melanoma cancer patients using granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-13 (IL-13) and that these DC have many of the same characteristics as DC differentiated using GM-CSF and IL-4. The DC generated in GM-CSF and IL-13 are CD14- and express high levels of the cell surface markers CD86, HLA-DR, and CD58, as do DC generated in GM-CSF and IL-4. The purity and yield of both DC populations are not significantly different. Furthermore, both populations of DC are effective at presentation of alloantigen as determined in a mixed lymphocyte response, and both are able to process and present soluble tetanus toxoid antigen to CD4+ T cells. Because we are interested in the generation of DC for antigen-specific cytotoxic T lymphocyte (CTL) generation, we compared the ability of peptide-pulsed DC differentiated in GM-CSF and IL-4 versus GM-CSF and IL-13 for the generation of influenza and MART-1 specific CTL. Both populations of DC induced CD3+ CD8+ CD4- and CD56- CTL, which could lyse the appropriate targets in an antigen-specific manner. Finally, both GM-CSF and IL-4 DC and GM-CSF and IL-13 DC yielded similar beta galactosidase expression levels after transduction with recombinant adenovirus containing the LacZ gene. These results suggest that DC generated in GM-CSF and IL-13 may be useful for immunotherapy and gene therapy protocols.

Topics: Antigens, Neoplasm; Breast Neoplasms; Cell Differentiation; Dendritic Cells; Genetic Therapy; Granulocyte-Macrophage Colony-Stimulating Factor; Humans; Immunophenotyping; Immunotherapy; Interleukin-13; Interleukin-4; Leukocytes, Mononuclear; Lymphocyte Culture Test, Mixed; MART-1 Antigen; Melanoma; Neoplasm Proteins; Neoplasms; T-Lymphocytes, Cytotoxic

Evidence is growing for both humoral and cellular immune recognition of human tumor antigens. Antibodies with specificity for antigens initially recognized by cytotoxic T lymphocytes (CTLs), e.g., MAGE and tyrosinase, have been detected in melanoma patient sera, and CTLs with specificity for NY-ESO-1, a cancer-testis (CT) antigen initially identified by autologous antibody, have recently been identified. To establish a screening system for the humoral response to autoimmunogenic tumor antigens, an enzyme-linked immunosorbent assay (ELISA) was developed using recombinant NY-ESO-1, MAGE-1, MAGE-3, SSX2, Melan-A, and tyrosinase proteins. A survey of sera from 234 cancer patients showed antibodies to NY-ESO-1 in 19 patients, to MAGE-1 in 3, to MAGE-3 in 2, and to SSX2 in 1 patient. No reactivity to these antigens was found in sera from 70 normal individuals. The frequency of NY-ESO-1 antibody was 9.4% in melanoma patients and 12.5% in ovarian cancer patients. Comparison of tumor NY-ESO-1 phenotype and NY-ESO-1 antibody response in 62 stage IV melanoma patients showed that all patients with NY-ESO-1(+) antibody had NY-ESO-1(+) tumors, and no patients with NY-ESO-1(-) tumors had NY-ESO-1 antibody. As the proportion of melanomas expressing NY-ESO-1 is 20-40% and only patients with NY-ESO-1(+) tumors have antibody, this would suggest that a high percentage of patients with NY-ESO-1(+) tumors develop an antibody response to NY-ESO-1.

Topics: Antibodies, Neoplasm; Antigens, Neoplasm; Autoantibodies; Breast Neoplasms; Colonic Neoplasms; Enzyme-Linked Immunosorbent Assay; Female; Humans; Lung Neoplasms; MART-1 Antigen; Melanoma; Melanoma-Specific Antigens; Membrane Proteins; Monophenol Monooxygenase; Neoplasm Proteins; Neoplasms; Ovarian Neoplasms; Proteins; Recombinant Proteins; Repressor Proteins

Dendritic cells (DCs) are professional antigen-presenting cells that process and present antigenic peptides and are capable of generating potent T-cell immunity. A murine tumor model was developed to evaluate methods of genetic immunization to the human MART-1/Melan-A (MART-1) melanoma antigen. A poorly immunogenic murine fibrosarcoma line (NFSA) was stably transfected with the MART-1 gene. This transfected tumor [NFSA(MART1)] grows progressively in C3Hf/Kam/Sed (H-2k) mice. Partial protection against a challenge with NFSA(MART1) could be achieved with i.m. injections of a MART-1 expression plasmid or with systemic administration of an adenovirus vector expressing MART-1. However, superior protection was achieved when granulocyte macrophage colony-stimulating factor/interleukin-4-differentiated murine DCs transduced with an adenovirus vector expressing MART-1 were used for immunization. Both partial and complete protection could be achieved with i.v. administration of MART-1-engineered DCs. Splenocytes from immunized mice contained MHC class 1-restricted CTLs specific for MART-1. This preclinical model of genetic immunization supports a therapeutic strategy for human melanoma.

Topics: Adenoviridae; Animals; Antigens, Neoplasm; Dendritic Cells; Female; Genetic Therapy; Humans; Immunization; MART-1 Antigen; Mice; Mice, Inbred C3H; Neoplasm Proteins; Neoplasms; Transfection