[Perspectives for tumour immunology: antigen-specific immunotherapy of malignant diseases].
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Publications and source records attributed to D Jäger.
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The ability of the immune system to recognize structurally altered, amplified or aberrantly expressed proteins can be used to identify molecules of etiologic relevance to cancer and to define targets for cancer immunotherapy. In the current study, ninety-four distinct antigens reactive with serum IgG from breast cancer patients were identified by immunoscreening breast cancer-derived cDNA expression libraries (SEREX). A serological profile was generated for each antigen on the basis of reactivity with allogeneic sera from normal individuals and cancer patients, and mRNA expression profiles for coding sequences were assembled based upon the tissue distribution of expressed sequence tags, Northern blots and real-time RT-PCR. Forty antigens reacted exclusively with sera from cancer patients. These included well-characterized tumor antigens, e.g. MAGE-3, MAGE-6, NY-ESO-1, Her2neu and p53, as well as newly-defined breast cancer antigens, e.g. kinesin 2, TATA element modulatory factor 1, tumor protein D52 and MAGE D, and novel gene products, e.g. NY-BR-62, NY-BR-75, NY-BR-85, and NY-BR-96. With regard to expression profiles, two of the novel gene products, NY-BR-62 and NY-BR-85, were characterized by a high level of testicular mRNA expression, and were overexpressed in 60% and 90% of breast cancers, respectively. In addition, mRNA encoding tumor protein D52 was overexpressed in 60% of breast cancer specimens, while transcripts encoding SNT-1 signal adaptor protein were downregulated in 70% of these cases. This study adds to the growing list of breast cancer antigens defined by SEREX and to the ultimate objective of identifying the complete repertoire of immunogenic gene products in human cancer (the cancer immunome).
Application of SEREX (serological analysis of recombinant tumor cDNA expression libraries) to different tumor types has led to the identification of several categories of human tumor antigens. In this study, the analysis of a breast cancer library with autologous patient serum led to the isolation of seven genes, designated NY-BR-1 through NY-BR-7. NY-BR-1, representing 6 of 14 clones isolated, showed tissue-restricted mRNA expression in breast and testis but not in 13 other normal tissues tested. Among tumor specimens, NY-BR-1 mRNA expression was found in 21 of 25 breast cancers but in only 2 of 82 nonmammary tumors. Structural analysis of NY-BR-1 cDNA and the corresponding genomic sequences in the recently released working draft of human genome indicated that NY-BR-1 is composed of 37 exons and has an open reading frame of 4.0-4.2 kb, encoding a peptide of Mr 150,000-160,000. A bipartite nuclear localization signal motif indicates a nuclear site for NY-BR-1, and the presence of a bZIP site (DNA-binding site followed by leucine zipper motif) suggests that NY-BR-1 is a transcription factor. Additional structural features include five tandem ankyrin repeats, implying a role for NY-BR-1 in protein-protein interactions. NY-BR-1 thus represents a breast tissue-specific putative transcription factor with autoimmunogenicity in breast cancer patients. In addition to NY-BR-1, a homologous gene, NY-BR-1.1, was identified in this study. NY-BR-1.1 shares 54% amino acid homology with NY-BR-1 and also shows tissue-restricted mRNA expression. However, unlike NY-BR-1, NY-BR-1.1 mRNA is expressed in brain, in addition to breast and testis. The exon structure of NY-BR-1.1 remains to be defined. Using human genome database, NY-BR-1 was localized to chromosome 10p11-p12, and NY-BR-1.1 was tentatively localized to chromosome 9.
Continued progress in the development of antigen-specific breast cancer vaccines depends on the identification of appropriate target antigens, the establishment of effective immunization strategies, and the ability to circumvent immune escape mechanisms. Methods such as T cell epitope cloning and serological expression cloning (SEREX) have led to the identification of a number target antigens expressed in breast cancer. Improved immunization strategies, such as using dendritic cells to present tumor-associated antigens to T lymphocytes, have been shown to induce antigen-specific T cell responses in vivo and, in some cases, objective clinical responses. An outcome of successful tumor immunity is the evolution of antigen-loss tumor variants. The development of a polyvalent breast cancer vaccine, directed against a panel of tumor-associated antigens, may counteract this form of immune escape.
The aim of this study was to determine whether the addition of whole body hyperthermia (WBH) to carboplatin (CBDCA) can induce responses in patients with platinum-resistant ovarian cancer. 16 pretreated patients with platinum-resistant ovarian cancer were entered on a Systemic Hyperthermia Oncological Working Group (SHOWG) study; (14 patients were eligible with 14 evaluable for toxicity and 12 for response). The patients were treated with WBH (Aquatherm) 41.8 degrees C x 60 min in combination with carboplatin (CBDCA) (area under the curve (AUC) of 8) every 4 weeks. Disease status was evaluated every two cycles. Patients were treated for a maximum of six cycles. One patient had a complete response (CR) and 4 had a partial response (PR). 4 patients had stable disease (SD). 3 patients had progressive disease (PD). 2 patients were unevaluable: 1 had a bowel obstruction shortly after her first treatment; the second patient achieved a CR, but only had one treatment secondary to an idiosyncratic reaction to sedative drugs. 2 patients entered on study were ineligible, as they did not meet criteria for platinum resistance; 1 entered a CR and 1 had SD. Dose-limiting toxicity, which required CBDCA dose reductions, was grade 4 thrombocytopenia. Other toxicities included neutropenia (grade 3/4), and nausea and/or vomiting. Consistent with preclinical modelling, these results suggests that 41.8 degrees C WBH can overcome platinum resistance in ovarian cancer. These observations suggest further investigation of the therapeutic potential of WBH in a group of patients who historically fail to respond to salvage therapies is warranted.
PURPOSE: Aim of the study was to examine the expectations of patients at the beginning and the satisfaction at the end of a hospital stay. The hospital settings were standardised. METHODS: 510 patients on the cardiological ward were asked to fill in a questionnaire on the first and last day of their stay. RESULTS: The admitted patients stated clear expectations in respect of the hospital facilities and staff. The most important aspects for the patients were the qualification of staff and the time physicians and nurses would devote to the patient, and the medical and technical equipment of the hospital. Beds per room, food, length and costs of the stay were less important in patients' expectations. On the day of discharge, the patients were very satisfied with the staff and medical equipment, in contrast to a low satisfaction regarding additional fees and the number of beds per room (three). CONCLUSIONS: Since cost-benefit is a basic need in running a hospital today, financial resources should be enhanced in the spheres which are equally medically important for fulfilling the expectations of the patients. Therefore, the number of staff and the qualification of the medical professionals should be financed instead of supporting architectural and room design. Accordingly, the patients' main criteria for choosing a hospital is the medical equipment provided and the qualification of the medical staff. In conclusion, these aspects should be publicized for meaningful decision-making. Medical professionals should be encouraged to inspire competence and to spend as much time as possible with each individual patient.
BACKGROUND: Sleep related hypoxemia (SRH) in chronic obstructive pulmonary disease (COPD) can be easily detected by pulse-oximetry and may contribute to the development of pulmonary hypertension (PH). Since several parameters for the quantification of SRH are in use, we investigated which of these parameters has the strongest relation to the awake pulmonary arterial pressure (PAP) and is able to distinguish between patients without and with PH. PATIENTS AND METHODS: 44 COPD-patients (awake PaO2 > or = 60 mm Hg) were investigated. PAP at rest (PAP; pathological threshold > 20 mm Hg) and under physical exercise (PAPB; p.t. > 28 mm Hg) were determined during daytime by Swan-Ganz-catheter. To quantify the degree of SRH the following parameters of nocturnal pulse-oximetry were used: mean nocturnal oxygen saturation (SaO2 m; p.t. < 90%), nadir SaO2 (SaO2 min; p.t. < 85%), and mean time of SaO2 < or = 90% in relation to total time of registration (t90; p.t. > 30%). Linear correlations and regressions as Chi 2-respectively Fisher-test were used for statistical analysis (p < 0.05). RESULTS: Generally there was only a weak relation between PAP and SRH. The best linear correlation at rest respectively under physical exercise was found between PAP and SaO2 min (r = -0.529 resp. -0.541, p < 0.001). Using the above defined thresholds for PAP and SaO2 patients could be most precisely separated into those without and with PH using SaO2 min with a threshold for the pathological range of < 85% (p = 0.030 resp. 0.002). t90 with a threshold > 30%, however, had a much worse selectivity (p = 0.487 resp. 0.057). CONCLUSIONS: In COPD-patients with SRH the closest relation can be found between nadir SaO2 and PAP resp. PAPB. Furthermore nadir SaO2 (< 85%) could more precisely separate patients into those without and with pulmonary hypertension than t90. The overall weak relation between nocturnal oxygenation and pulmonary hypertension shows, however, that other factors such as daytime PaO2, hypercapnia or emphysema are involved in the development of pulmonary hypertension in COPD.
Tumour associated antigens recognised by cellular or humoral effectors of the immune system are potential targets for antigen specific cancer immunotherapy. Different categories of cancer antigens have been identified that induce cytotoxic T lymphocyte (CTL) responses in vitro and in vivo, namely: (1) "cancer testis" (CT) antigens, expressed in different tumours and normal testis, (2) melanocyte differentiation antigens, (3) point mutations of normal genes, (4) self antigens that are overexpressed in malignant tissues, and (5) viral antigens. Clinical studies with peptides and proteins derived from these antigens have been initiated to study the efficacy of inducing specific CTL responses in vivo. Immunological and clinical parameters for the assessment of antigen specific immune responses have been defined-delayed type hypersensitivity (DTH), CTL, autoimmmune, and tumour regression responses. Specific DTH and CTL responses and tumour regression have been observed after the intradermal administration of tumour associated peptides alone. Peptide specific immune reactions were enhanced after using granulocyte macrophage stimulating factor (GM-CSF) as a systemic adjuvant by increasing the frequency of dermal antigen presenting Langerhans cells. Complete tumour regression has been observed in the context of measurable peptide specific CTL. However, in single cases with disease progression after an initial tumour response, either a loss of single antigens targeted by CTL or of the presenting major histocompatibility complex (MHC) class I allele was detected, pointing towards immunisation induced immune escape. Cytokines to modulate antigen and MHC class I expression in vivo are being evaluated to prevent immunoselection. Recently, a new CT antigen, NY-ESO-1, has been identified on the basis of spontaneous antibody responses to tumour associated antigens. NY-ESO-1 appears to be one of the most immunogenic antigens known to date, with spontaneous immune responses observed in 50% of patients with NY-ESO-1 expressing cancers. Clinical studies have been initiated to evaluate the immunogenicity of different NY-ESO-1 constructs to induce both humoral and cellular immune responses in vivo.
The identification of tumor-associated antigens recognized by cellular or humoral effectors of the immune system has opened new perspectives for cancer immunotherapy. Different categories of cancer-associated antigens have been described as targets for CD8+ T cells in vitro and in vivo: (1) 'cancer-testis' (CT) antigens expressed in different tumors and normal testis; (2) melanocyte differentiation antigens; (3) point mutations of normal genes; (4) antigens that are overexpressed in malignant tissues, and (5) viral antigens. Clinical trials with antigenic peptides have been initiated to induce specific immunological responses in vivo. Immunological and clinical parameters for the assessment of peptide-specific reactions have been defined: DTH, CD8+ T cell, autoimmune and tumor regression responses. Preliminary results show that tumor-associated peptides alone elicit specific DTH and CD8+ T cell responses associated with tumor regression after intradermal vaccination. Granulocyte macrophage colony-stimulating factor has been shown to enhance peptide-specific immune reactions by amplification of dermal antigen-presenting dendritic cells. Complete tumor regressions have been observed after the induction of CD8+ T cell responses by peptide immunization. Based on these results, active immunotherapy with tumor-associated antigens may be a promising approach for patients in adjuvant treatment situations, who are at high risk for tumor recurrence. Recently, a strategy utilizing spontaneous antibody responses to tumor-associated antigens (SEREX) has led to the identification of a new CT antigen, NY-ESO-1. NY-ESO-1-specific spontaneous humoral and cellular immune responses were found in approximately 50% of patients with NY-ESO-1-positive tumors. Clinical studies have been initiated to evaluate the immunological effects of immunization with NY-ESO-1 peptides in cancer patients with detectable or absent immunity against NY-ESO-1.
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Adaptive immune responses begin after antigen-bearing dendritic cells (DCs) traffic from peripheral tissues to lymph nodes. Here, we show that DC migration from skin to lymph nodes utilizes the leukotriene C(4) (LTC(4)) transporter multidrug resistance-associated protein 1 (MRP1). DC mobilization from the epidermis and trafficking into lymphatic vessels was greatly reduced in MRP1(-/-) mice, but migration was restored by exogenous cysteinyl leukotrienes LTC(4) or LTD(4). In vitro, these cysteinyl leukotrienes promoted optimal chemotaxis to the chemokine CCL19, but not to other related chemokines. Antagonism of CCL19 in vivo prevented DC migration out of the epidermis. Thus, MRP-1 regulates DC migration to lymph nodes, apparently by transporting LTC(4), which in turn promotes chemotaxis to CCL19 and mobilization of DCs from the epidermis.
Cancer-testis antigen NY-ESO-1 is one of the most immunogenic tumor antigens defined to date. Spontaneous humoral and CD8+ T-cell responses to NY-ESO-1 are detected in 40-50% of patients with advanced NY-ESO-1-expressing tumors. A clinical trial was initiated to study the immunological effects of intradermal vaccination with 3 HLA-A2-binding NY-ESO-1 peptides in 12 patients with metastatic NY-ESO-1-expressing cancers. Seven patients were NY-ESO-1 serum antibody negative, and five patients were NY-ESO-1 serum antibody positive at the outset of the study. Primary peptide-specific CD8+ T-cell reactions and delayed-type hypersensitivity responses were generated in four of seven NY-ESO-1 antibody-negative patients. Induction of a specific CD8+ T-cell response to NY-ESO-1 in immunized antibody-negative patients was associated with disease stabilization and objective regression of single metastases. NY-ESO-1 antibody-positive patients did not develop significant changes in baseline NY-ESO-1-specific T-cell reactivity. However, stabilization of disease and regression of individual metastases were observed in three of five immunized patients. These results demonstrate that primary NY-ESO-1-specific CD8+ T-cell responses can be induced by intradermal immunization with NY-ESO-1 peptides, and that immunization with NY-ESO-1 may have the potential to alter the natural course of NY-ESO-1-expressing tumors.
Characterization of immunogenic human melanoma antigens has been a major focus of tumor immunologists over the past two decades, and a broad array of antigens recognized by antibodies and T cells in the autologous host has been defined. In the present study, a melanoma library was screened by SEREX (serological analysis of cDNA expression libraries), and 43 genes were isolated, 2 of which, NY-MEL-1 and NY-MEL-3, encode novel gene products with differential tissue expression. NY-MEL-1 encodes a new rab GTP-binding protein, rab38. Among >40 rab proteins, rab38 has a unique COOH terminus which would allow posttranslational farnesylation and palmitoylation, lipid modifications normally occurring in ras proteins but not in other rab proteins. It is also the only rab gene showing a predominant mRNA expression in melanocytes, a cell-specific expression pattern likely related to melanosomal transport and docking. Northern blot analysis showed no detectable expression in other normal tissues. Consistent with this lineage specificity, rab38 mRNA is expressed in 80-90% of melanoma (17 of 19), but rarely in nonmelanocytic malignancies (1 of 16). The second novel gene isolated, NY-MEL-3, encodes a mitotic protein highly homologous to the Xenopus chromosome condensation protein XCAP-G, designated hCAP-G. Analysis of hCAP-G mRNA expression showed highest expression in the testis among normal tissues and variable expression in tumor cells, reflecting the proliferative activity in these cells. This mitosis-related expression suggests hCAP-G as a possible proliferation marker and a potential prognostic indicator in cancer. These findings provide further support that SEREX can define biologically significant molecules in cancer.
Human hepatocytes cultured serum-free for up to 6 weeks were used to study expression and induction of enzymes and membrane transport proteins involved in drug metabolism. Phase I drug metabolizing enzymes cytochrome P450 (CYP)1A1, CYP1A2, CYP2C9, CYP2C19, CYP2E1, and CYP3A4 were detected by Western blot analyses and, when appropriate, by enzymatic assays for ethoxyresorufin-O-deethylase(EROD)-activity and testosterone-6beta-hydroxylase(T6H)-activity. Expression of the membrane transporter multi-drug resistance protein (P-glycoprotein, MDR-1), multidrug resistance-associated protein (MRP-1), and lung-resistance protein (LRP) was maintained during the culture as detected by RT-PCR and Western blot analyses. Model inducers like rifampicin, phenobarbital, or 3-methylcholanthrene and beta-naphtoflavone were able to induce CYP1A or CYP3A4 as well as EROD or T6H activities for up to 30 days. CYP2C9, CYP2C19 and CYP2E1 expression was maintained but not inducible for 48 days. Also, rifampicin and phenobarbital were unable to increase MDR-1 and MRP-1 protein levels significantly.
Peptides derived from human tumor antigens have been used in a number of clinical trials to induce specific immune responses against autologous tumors in cancer patients. Although favorable clinical results were observed in single patients, immune responses correlating with tumor regression were either not detected or in case of responses, the T-cell specificity was difficult to demonstrate. In this study, we analyzed antigen-specific T-cell responses induced in the skin and in peripheral blood lymphocytes (PBL) in an HLA-A2-positive melanoma patient. The patient showed major regression of metastatic melanoma under continued immunization with peptides derived from the melanocyte differentiation antigens Melan A/MART-1, tyrosinase and gp100/Pmel17. Based on the identification of different T-cell receptor (TCR) families reactive with Melan A/MART-1, we have demonstrated that i.d. immunization with peptides alone leads to oligoclonal expansion of Melan A/MART-1-specific cytotoxic T lymphocytes (CTL), detectable in local delayed-type hypersensitivity (DTH) reactions and PBL. A monoclonal expansion of a Melan A/MART-1-specific TCR VB 16 CTL was reproducibly observed after in vitro stimulation with Melan A/MART-1 peptides. The same TCR VB 16 CTL clone was detected in skin biopsies taken from vitiligo areas. Our findings provide strong evidence for the effective induction of specific T-cell responses to Melan A/MART-1 by i.d. immunization with peptide alone, which accounts for dermal depigmentation, specific cytotoxicity against Melan A/MART-1-expressing melanoma cells and clinical tumor regression.
NY-ESO-1, a member of the cancer-testis family of antigens, is expressed in a subset of a broad range of different human tumor types. Patients with advanced NY-ESO-1-expressing tumors frequently develop humoral immunity to NY-ESO-1, and three HLA A2-restricted peptides were defined previously as targets for cytotoxic CD8(+) T cells in a melanoma patient with NY-ESO-1 antibody. The objectives of the present study were (i) to develop enzyme-linked immunospot (ELISPOT) and tetramer assays to measure CD8(+) T cell responses to NY-ESO-1, (ii) to determine the frequency of CD8(+) T cell responses to NY-ESO-1 in a series of HLA-A2 patients with NY-ESO-1 expressing tumors, (iii) to determine the relation between CD8(+) T cell and humoral immune responses to NY-ESO-1, and (iv) to compare results of NY-ESO-1 ELISPOT assays performed independently in two laboratories with T cells from the same patients. NY-ESO-1 ELISPOT and tetramer assays with excellent sensitivity, specificity, and reproducibility have been developed and found to correlate with cytotoxicity assays. CD8(+) T cell responses to HLA-A2-restricted NY-ESO-1 peptides were detected in 10 of 11 patients with NY-ESO-1 antibody, but not in patients lacking antibody or in patients with NY-ESO-1-negative tumors. The results of ELISPOT assays were concordant in the two laboratories, providing the basis for standardized monitoring of T cell responses in patients receiving NY-ESO-1 vaccines.
Serological analysis of expression cDNA libraries (SEREX) derived from two small cell lung cancer (SCLC) cell lines using pooled sera of SCLC patients led to the isolation of 14 genes, including 4 SOX group B genes (SOX1, SOX2, SOX3, and SOX21) and ZIC2. SOX group B genes and ZIC2 encode DNA-binding proteins; SOX group B proteins regulate transcription of target genes in the presence of cofactors, whereas ZIC2 is also suspected to be a transcriptional regulator. These genes are expressed at early developmental stages in the embryonic nervous system, but are down-regulated in the adult. Although SOX2 mRNA can be detected in some adult tissues, ZIC2 is expressed only in brain and testis, and SOX1, SOX3, and SOX21 transcripts are not detectable in normal adult tissues. Of SCLC cell lines tested, 80% expressed ZIC2 mRNA, and SOX1, SOX2, and SOX3 expression was detected in 40%, 50%, and 10%, respectively. SOX group B and ZIC2 antigens elicited serological responses in 30-40% of SCLC patients in this series, at titers up to 1:10(6). In sera from 23 normal adults, no antibody was detected against SOX group B or ZIC2 proteins except for one individual with low-titer anti-SOX2 antibody. Seroreactivity against SOX1 and 2 was consistently higher titered than SOX3 and 21 reactivity, suggesting SOX1 and/or SOX2 as the main antigens eliciting anti-SOX responses. Although paraneoplastic neurological syndromes have been associated with several SCLC antigens, neurological symptoms have not been observed in patients with anti-SOX or anti-ZIC2 antibodies.
Since human hepatocytes are available only in limited number, the development of a serum-free culture system for long-term cultivation of differentiated and functional hepatocytes is of great importance. Here we describe the culture of human hepatocytes in a chemically defined serum-free medium for up to 5 weeks. Cell morphology was assayed by light and electron microscopy and revealed a well-preserved cellular morphology. Marker proteins for epithelial and bile duct cells, cytokeratin (CK) 18 and 19, and liver-specific proteins, like phosphoenolpyruvate carboxykinase-2 (PCK2) and serum proteins, were expressed. Liver-enriched transcription factors CCAAT/enhancer binding protein alpha (C/EBPalpha) and hepatocyte nuclear factor-4 (HNF-4), cytokine and mitogen activated factors (nuclear factor kappa B) NFkappaB, and activator protein-1 (AP-1) were maintained and active for several weeks in our cultures. In summary, our serum-free culture system allows the culture of differentiated human hepatocytes for several weeks. It may serve as a model system for metabolic, pharmacologic-toxicologic studies, and studies on human pathogens under defined chemical conditions.