The Relationship of Kynurenine and Neopterin Levels and Their Association with a Selection of Other Immune Markers in Chronic Myeloid Leukaemia Patients.

Among malignant diseases, chronic myeloid leukaemia (CML) is one of the best suited candidates for immunotherapy. For this purpose it is necessary to broaden the present knowledge on the immunology of this disease. As a part of such a project, the levels of kynurenine (KYN) and neopterin (NPT) were studied in 28 CML patients and in the same number of healthy subjects. At diagnosis, both KYN and NPT levels were found to be elevated in a significant portion of the patients and dependent on their leukocyte count. As in the case of KYN, increased NPT levels dropped after achieving remission. When correlating KYN and NPT levels with a selection of other markers tested, significant association was revealed only in the case of CRP and IL-6. However, there were several patients with increased KYN levels in whom NPT was not detected, and vice versa. The relapse of the disease observed in two patients was accompanied by an increased level of NPT in both cases, but by an increased level of KYN in only one of them. No significant correlation was found between KYN and NPT levels in sera taken at diagnosis. However, when the whole set of sera was taken into consideration, the association became statistically significant. Although the data obtained revealed a number of similarities between KYN and NPT production in CML patients, it also suggested a difference in the kinetics of these two biomarkers' production.

In vitro and in vivo effects of reovirus on HPV16-transformed mice cells.

UNLABELLED: Oncolytic viruses are examined to serve as anticancer therapeutics. It is expected that in addition to direct oncolytic effect their action will also help eliciting a solid antitumor immunity. In presented series of experiments we have employed two HPV16-transformed mouse (strain C57/B6) cell lines, TC-1 and MK16/III/ABC (MK16), and reovirus type 3, strain Dearing (RV). Both cell lines are highly susceptible to RV and produce large amounts of infectious virus in vitro while normal human are not susceptible to RV. Still, some differences were encountered. TC-1 cells produced moderately lesser amounts of infectious virus, but, paradoxically, were more efficient producers of delta1 antigen of RV and as a consequence of virus infection died more rapidly than simultaneously infected MK16 cells. Minor differences between the cell lines were observed in the percentage of cells arrested in theG2/M phase of the cell cycle and in some markers of apoptosis. When inoculating high doses (5x106) of infected cells (MOI 10 PFU/cell) into syngeneic animals their oncogenic activity was strongly suppressed, nearly completely in the case of MK16 cells and somewhat less efficiently in the case of more oncogenic TC-1 cells. Immunizing experiments in which non-oncogenic doses (106) of RV infected TC-1 cells were tested in parallel with the same doses of irradiated cells brought surprising results. When immunized animals were challenged with TC-1 cells, the irradiated cells proved to be a much better immunogen that the infected cells. However, when challenged with MK16 cells the opposite was true. It is believed that this difference was associated with the different biological properties of the cell lines tested. KEYWORDS: reovirus type 3, HPV16-transformed mouse cell lines, apoptosis, cell cycle, immunization/challenge experiments.

[Will vaccines appear on the scene of oncology in the near future?]. / Dockáme se protinádorových vakcín?

In parallel with the increasing knowledge of the role played by the immune system in the control oftumourgrowth, the efforts to develop anti-cancer vaccines intensify. In the present time two highly efficient prophylactic vaccines against the virus-induced cancers are in use, but a rapid progress in the development of anti-cancer therapeutic vaccines can also be seen. It is conditioned by an increasing understanding of the biology of the tumor cells and the rapid progress in the field of immunology. Nevertheless, these developments are associated with a number of difficulties, among which the immunosuppressive activities of the tumor cells and the tumor microenvironment are the most important. On the example of chronic myeloid leukemia the author proposes a strategy for the development ofa therapeutic cancer vaccine.

Isolation and properties of gene-modified mouse bcr-abl-transformed cells expressing various immunostimulatory factors.

UNLABELLED: B210 cells are murine (BALB/c) cells transformed by bcr-abl fusion gene. After intravenous administration they are capable of inducing leukaemia-like disease in syngeneic mice. From these cells a thymidine-kinase less subline was derived. It was significantly less pathogenic than the parental cells. However, a highly pathogenic clone denoted B210cTK-/cl-2 was isolated from its population. As determined by Western blotting, these cells produced more p210 protein than the parental B210 cells. To successfully transfect these cells a modified electroporation method was introduced. Bicistronic plasmids carrying gene for herpes simplex thymidine kinase (HSV TK) and the gene for either granulocyte-monocyte colony stimulation factor (GM-CSF), interleukin-2 (IL-2) or interleukin 12 (IL-12) were used for the transfection experiments. Gradually, cell lines producing these cytokines were isolated in media supplemented with hypoxantin, aminopterin and thymidine (HAT). All of them were highly sensitive to ganciclovir in vitro confirming that the cells produced HSV TK. The genetic modification of B210cTK-/cl-2 was associated neither with the alteration of p210 bcr-abl production nor with any changes in expression of MHC class I molecules. From populations of each of the three lines several cell clones were isolated and tested for the production of the respective cytokines. The original uncloned population and several clones differing in the cytokine production were administered intravenously into mice. All animals survived without symptoms of the disease suggesting that the gene-modification was associated with the loss of pathogenicity. KEYWORDS: CML, Bcr-Abl, HSV TK, cytokines, gene-modified tumour cells, pathogenicity.

Immunological profiles of patients with chronic myeloid leukaemia. I. State before the start of treatment.

In view of the increasing interest in the immunotherapy of CML it seems highly desirable to broaden the present knowledge on the immune reactivity of CML patients. A group of 24 patients and 24 healthy controls were studied for the total of 15 immunological parameters, including the prevalence of antibodies against human herpesviruses and papillomaviruses. To clearly discriminate between changes associated with the disease and those induced by the therapy, all patients were enrolled prior to the start of any anti-leukaemic therapy. Statistically significant differences between patients and controls were found in the levels of IgA, C4 component of complement, CRP and IL-6, the production of Th1 cytokines in stimulated CD3 cells and the E. coli stimulatory index. The analysis of the interrelationship between the results obtained in the individual patients presented some unexpected findings, such as the lack of correlation between the CRP and IL-6 levels. It will be the purpose of a follow-up to determine whether and how the immune status of the patients prior to the treatment correlates with their response to therapy and how the individual immunological profiles change in the course of the disease. These observations will be utilized in the future immunotherapeutic studies to constitute the vaccine- and placebo-treated groups.

Presence of Epstein-Barr virus DNA in carcinomas of the palatine tonsil.

The presence of Epstein-Barr virus genetic material was demonstrated in thin sections of biopsy specimens in 6 of 7 carcinomas of human palatine tonsil by the in situ hybridization test. The biopsy specimens from 4 tonsillar carcinomas exhibited a strong positive reaction; two biopsy specimens were weakly positive. Two tumor-free biopsy specimens were negative. None of the thin sections reacted with 3H-labeled herpes simplex virus DNA probe.

[Cervical cancer uteri: from the etiology to prophylactic vaccine]. / Karcinom delozního cípku: od poznání etiologie k profylaktické vakcíne.

The authors briefly summarize the history of the research on the cervical cancer (CC) which has resulted in the recognition of human papillomaviruses (HPV) as the key etiological factors in CC. They describe the HPV properties and the process leading to the development of prophylactic vaccines directed against HPV genotypes most frequently responsible for the development of CC. They summarize the results of the recent studies with these vaccines and strongly recommend their introduction. At the same time they stress that the vaccination programs must not disturb the present system of preventive gynecological check-ups. These will remain the most efficient weapon in the war against CC for at least two decades.

Human papillomavirus DNA and antibodies to human papillomaviruses 16 E2, L2, and E7 peptides as predictors of survival in patients with squamous cell cervical cancer.

PURPOSE: To assess whether human papillomavirus (HPV) DNA detection in cervical cancer specimens, or antibodies to selected HPV 16 peptides are predictors of tumor recurrence and long-term survival in patients with squamous cell invasive cervical cancer. SUBJECTS AND METHODS: Four hundred seventy-one cases included in two population-based case-control studies underwent follow-up evaluation. The survival and cause of death were ascertained for 410 cases (87%), with a median follow-up time of 4.6 years after diagnosis. HPV DNA was assessed using an L1 polymerase chain reaction (PCR)-based system and Southern hybridization (SH) on scraped cytologic specimens or biopsies. HPV 16 antibodies to E2, L2, and E7 peptides were detected with enzyme-linked immunosorbent assay (ELISA). RESULTS: Clinical stage was the only independent prognostic factor for recurrence or survival. Although seropositivity to HPV 16 E7/3 peptide predicted a twofold excess risk of mortality (adjusted hazards ratio [HRa] = 2.0; 95% confidence interval [CI], 1.2 to 3.3), the association was restricted to stage I (HRa = 6.6; 95% CI, 1.2 to 37.6) and II (HRa = 5.9; 95% CI, 2.1 to 16.5) patients. The presence of HPV DNA (HRa = 0.9; 95% CI, 0.5 to 1.5), different estimates of the HPV viral load and the HPV type identified were not predictors of tumor recurrence or survival. CONCLUSION: The presence of antibodies to HPV 16 E7 proteins is of prognostic value in early-stage cervical cancer. Our results provide strong evidence that detection and typing of HPV DNA in cervical cells or tissues is not a prognostic factor for recurrence or survival.

Use of polyclonal rabbit antibodies for detection of the bcr-abl fusion zone in cells transfected with experimental bcr-abl DNA vaccines.

Rabbits were immunized with peptides covering the fusion zone of the chimeric bcr-abl protein in order to prepare antibodies capable of detecting the expression of a selected portion of this fusion zone, by a variety of experimental genetic vaccines. Three peptides of different size covering the b3a2 fusion zone, either unmodified or modified by the omission of alanine at the N-terminal of the a2 section of the fusion zone, and one peptide covering the unmodified b2a2 fusion zone were used. All were capable of eliciting antibodies reactive with the respective immunizing peptides. Their cross-reactivities, especially the results of cross-absorption experiments, strongly suggested that the serum of the rabbit immunized with an octadekapeptide mimicking the b3a2 fusion zone contained antibodies against a novel antigenic determinant created by the chimeric protein, and also against an epitope present in the adjacent a2 section but no antibody reactive with the adjacent b3 region. In Western blotting, these antibodies were capable of detecting the p210bcr-abl or a portion of it (a 25 amino acid-long sequence covering the b3a2 fusion zone) in lysates of 293T cells transfected with plasmids that carried either the full cDNA of the bcr-abl gene or a fragment thereof fused with either the HSP70 gene or certain other genes.

Characteristics of two mouse bcr-abl-transformed cell lines. II. Pathological lesions induced in mice.

Groups of six BALB/c mice each were intravenously inoculated with lethal doses of Ba-P210 (B210) or 12B1 cells and examined by autopsy, histology, special staining methods, enzyme histochemistry and immunohistochemistry. Clinical symptoms related to neoplasia consisted of a poor nutritional state, anaemia, mild to moderate dehydration and apathy. Paresis was apparent in three mice inoculated with 12B1 cells. Necropsy revealed splenomegaly in all animals. Sporadic haemorrhages in the lungs and enlargement of some lymph nodes were seen in some of the animals. Histological examination showed neoplastic cells in the spleen, in the bone marrow of the sternum, in the lung interstitium and in sinusoids of the liver in all mice. In six of nine brains examined, mild to moderate infiltration by neoplastic cells was observed. In all but two mice mild infiltration of the kidneys was found. The enlargement of lymph nodes was caused by an accumulation of neoplastic cells. The paresis was due to neoplastic infiltration of the vertebra, epidural space and spinal roots. Staining with Sudan black revealed cytoplasmic granules in neoplastic cells; however, the peroxidase reaction was negative. Numerous neoplastic cells disseminated in the red pulp of the spleen were reactive with CD3, CD79beta, CD11b and with neutrophil antibodies. We classified the disease induced by both of the cell lines as acute myeloid undifferentiated leukaemia (AML MO).

Characteristic of two mouse bcr-abl-transformed cell lines: I. General properties of the cells.

In an effort to develop an experimental system suitable for immunological studies in which Bcr-Abl-positive cells are to be used as antigens, we examined the properties of two mouse (Balb/c) established cell lines that express the Bcr-Abl protein and are oncogenic for syngeneic animals. Under standard conditions the two cell lines, viz. Ba-p210 (B210) and 12B1, expressed comparable amounts of the Bcr-Abl protein. However, they differed in a number of characteristics. From the morphological point of view, B210 cells were the more homogeneous, being mainly represented by leukaemic blastic cells with a large number of AgNORs as markers indicating a high proliferative activity. 12B1 cells were more polymorphic and giant cells were detected within their populations. Many 12B1 cells exhibited nuclear segmentation and "band-like" structures. Markers of proliferation were less frequent in 12B1 and the tendency for aging was more pronounced in these cells. The 12B1 cells were slightly more sensitive to imatinib mesylate than B210 cells. In B210 cells, the expression of MHC class I was downregulated, which was not the case with 12B1 cells. Both cell lines induced leukaemia-like disease in mice after intravenous application but, as compared with B210, 12B1 cells were about 100 times more oncogenic and the disease they induced was more aggressive. Moreover, 12B1, but not B210, induced tumours after subcutaneous or intraperitoneal inoculation.

[Promise of immunotherapy of the chronic myeloid leukaemia]. / Moznosti imunoterapie chronické myeloidní leukémie.

Because of the presence of unique antigens, chronic myeloid leukaemia (CML) represents an appealing target for immunotherapy. The progress achieved in the fields of gene therapy, tumour immunology and vaccinology offers a wide spectrum of methods that could be utilized for the development of therapeutic vaccines against CML. Experience obtained in several clinical studies with peptide-based vaccines have made it clear that it is possible to induce specific immune reactivity; however, its clinical efficacy has been low if any. Studies in mouse systems, which are under way, should be helpful in defining the optimal strategy for immunizing human subjects against bcr-abl positive cells. The author adduces some advantages, but also the limitations, of animal models for this purpose. He also comments on the possibility that the bcr-abl-based therapeutic vaccines might be found ineffective and proposes procedures how to deal with the problem.

Local cytokine treatment of HPV16-associated tumours results in inhibition of their lung metastases.

Experiments were designed to examine whether local cytokine therapy of subcutaneous (s.c.) tumours results in inhibition of their lung metastases. Moderately immunogenic, major histocompatibility complex (MHC) class I and II negative. B7 negative, metastasizing murine carcinoma MK16 transplantable in syngeneic mice was obtained by co-transfection of human papilloma virus type 16 (HPV 16) E6/E7 and activated H-ras oncogene plasmid DNA into C57BL/6 kidney cells. After s.c. transplantation of the malignantly converted MK16 cells, the majority of the transplanted mice developed lung metastases; the number and size of the lung metastases increased with the increasing size of the s.c. tumour. Therapy of 5-day MK16 tumours by peritumoral administration of recombinant interleukin-2 (IL-2) and recombinant interleukin-12 (IL-12) inhibited growth of the s.c. MK16 tumour transplants and reduced the number of MK16 lung metastases. To investigate the antimetastatic effect of IL-2 and IL- 12 in a clinically more relevant setting, surgical minimal residual tumour disease was utilized. Subcutaneously growing MK16 carcinomas, 8-12 mm in diameter, were removed on day 30 and the operated mice were injected with IL-2 or IL- 12 on days 35-39 and 42-46 at the site of the operation. Treatment with IL-2 significantly reduced the percentage of MK16 tumour recurrences as well as the number of lung metastases, whereas the effect of IL- 12 was substantially weaker and statistically insignificant.

Interleukin 2 gene therapy of residual disease in mice carrying tumours induced by HPV 16.

Experiments were designed to examine the efficacy of IL-2 gene therapy in a surgical minimal residual tumour disease, using moderately immunogenic MK16/1/IIIABC murine cells transformed by activated ras and HPV 16 E6/E7 oncogenes (MK16 cells). Previously we demonstrated that surgical minimal residual tumour disease (SMRTD) could be effectively cured when murine Mc12 sarcoma had been resected and the operated mice were treated with irradiated Mc12 sarcoma cells engineered to secrete IL-2. In this study we performed IL-2 gene therapy of MK16 carcinoma with two types of irradiated MK16-unrelated tumour cell vaccines. One type of vaccine was derived from MHC class I-matched Mc12 sarcoma cells engineered to secrete IL-2 and the other from MHC class I-discordant IL-2 producing plasmacytoma X63-m-IL-2. The vaccines did not share any tumour rejection antigen with the MK16 cells and served exclusively as a local source of IL-2 production. Both vaccines were capable of inhibiting MK16 tumours when administered peritumorally up to 15 days after MK16 tumour challenge. The irradiated MHC class I-matched and IL-2-producing Mc12 sarcoma vaccine was then selected for therapy of MK16 SMRTD. Whereas the recurrence rate in the operated MK16 carcinoma bearers was 80%, so that only 20% of mice were cured by surgery, approximately 65% of the MK16 carcinoma bearers were permanently protected when the surgery was followed by local administration of the IL-2-producing Mc12 sarcoma vaccine.

IL-2 as adjuvant for vaccination with cells malignantly converted by HPV 16 or 3-MC.

Experiments were designed to investigate the effects of murine recombinant IL-2 used as adjuvant for tumour vaccines in two model systems. The first system employed the Syrian hamster K3/II cell line transformed malignantly in vitro with DNA from E6-E7 oncogenes from HPV 16 and transplanted in Syrian hamsters. The second system made use of murine sarcoma Mc 12 induced with MC and transplanted in histocompatible mice. Both tumours were previously shown to express TRA capable of inducing transplantation resistance. It has been demonstrated here that the effect of the immunization in both tumour model systems could be substantially increased by IL-2 injected repeatedly at the site of vaccination. Some of the experimental mice were sacrificed after immunization and their spleen as well as regional lymph node cells were used for phenotypic analysis. IL-2 administration was found to be accompanied with an increase of TCR alpha beta(+), CD4(+) T cells in the spleen. Also in regional lymph nodes the T cell subsets showed a characteristic kinetics due to IL-2 administration. Following the IL-2 treatment, the percentage of lymph node TCR alpha beta(+), CD4(+) and CD8(+) cells dropped to less than half of the pretreatment values and then again gradually increased. No such kinetics was observed in vaccinated mice that did not receive IL-2. These results suggest that local administration of IL-2 at the site of vaccination elicits, in addition to the reaction in regional lymph nodes, a systemic reaction detectable in the spleen; they also suggest that the increase of CD4(+), TCR alpha beta(+) T splenocytes may play an important role in the mechanism of the observed adjuvant effect of IL-2. The adjuvant IL-2 effect augmenting the function of cell vaccines expressing HPV 16 E6-E7 oncoproteins deserves further studies, particularly with regard to its prospective utilization for treatment of human cervical carcinoma.

Prophylactic, therapeutic and anti-metastatic effects of BMDC and DC lines in mice carrying HPV 16-associated tumours.

Oncogenic, moderately immunogenic MK16/1/IIIABC (MK16) cells were previously established by co-transfection of HPV 16 E6/E7 and activated H-ras oncogene DNA into C57BL/6 kidney cells. Subcutaneous transplantation of the MK16 cells produced progressively growing neoplasms which metastasized spontaneously to lungs. In this communication we report that prophylactic administration of bone marrow-derived dendritic cells (BMDC) as well as dendritic cell (DC) lines DC2.4 and JAWS II at the site of subsequent MK16 tumour transplants inhibited tumour growth and reduced the number of lung metastases. Similarly, in therapeutic experiments, administration of BMDC and DC lines at the site of the growing MK16 tumours or at the site of MK16 tumour residua after surgery inhibited tumour growth. Both BMDC-based vaccines and vaccines based on DC lines had also an antimetastatic effect. These results indicate that the DC line-based vaccines, which represent a standard, well-characterized and more homogeneous material, technically easier to prepare than the fresh BMDC-based vaccines, can be utilized for therapy of surgical minimal residual disease in HPV 16-associated neoplasms and are prospective for relevant clinical trials.

Phosphonylmethyl ethers of acyclic nucleoside analogues: inhibitors of HSV-1 induced ribonucleotide reductase.

Diphosphates of N-(S)-(3-hydroxy-2-phosphonylmethoxypropyl) and N-(2-phosphonylmethoxyethyl) derivatives of purine and pyrimidine heterocyclic bases inhibit HSV-1 encoded ribonucleotide reductase. Of the compounds studied, the most efficient inhibitors of CDP reduction (at 5.1 mumols.l-1) by the HSV-1-encoded enzyme are HPMPApp (IC50 = 0.9 mumols.l-1) and PMEApp (IC50 = 8 mumol.l-1). PMEApp does not inhibit the enzyme isolated from the mutant HSV-1 KOS strain PMEAr which is resistant to PMEA at a concentration of 100 micrograms/ml. The enzyme isolated from the PMEA-resistant virus strain is also insensitive to inhibitory effects of hydroxyurea and HPMPApp. Thus, the inhibitory potency of HPMPApp and PMEApp toward HSV-1 encoded ribonucleotide reductase might be connected with the anti-HSV activity of HPMPA and PMEA.

Properties of a 9-(2-phosphonylmethoxyethyl)adenine (PMEA)-resistant herpes simplex virus type 1 virus mutant.

After repeated passages of herpes simplex type 1 (HSV-1) KOS virus in the presence of 9-(2-phosphonylmethoxyethyl)adenine (PMEA) a mutant denoted PMEAr HSV-1 was isolated which grew well in the presence of 50-100 micrograms.ml-1 of the drug. PMEAr HSV-1 was still sensitive to the related phosphonate analogue (S)-9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA). In fact, it was more susceptible to the action of HPMPA than the original virus. PMEAr HSV-1 also retained sensitivity to 5-bromo-2'-deoxyuridine and other, viral thymidine kinase-dependent substances such as (E)-5-(2-bromovinyl)-2'-deoxyuridine. However, PMEAr HSV-1 was much less sensitive to acyclovir, 1-(beta-D-arabinofuranosyl)cytosine and 1-(beta-D-arabinofuranosyl)thymine than the parental KOS virus.

Epstein-Barr virus nuclear antigen type 1 binding: electron microscopy.

Epstein-Barr virus (EBV) nuclear antigen type-1 (EBNA-1) was extracted and purified from Raji cells by chromatography on DNA-Sepharose and Blue-dextran Sepharose. Its complexes with plasmid pM765-10 derived from EBV (strain M-ABA) DNA were visualized by electron microscopy. The criteria of specificity were as follows: (1) preferential binding of EBNA-1 to the ori-P region of pM765-10; (2) specific enlargement of EBV DNA/EBNA-1 complexes with anti-EBNA-1 (IR-3) IgG antibody; and (3) resistance of the resulting EBV DNA/EBNA-1/anti-EBNA-1 antibody complexes to treatment with 1.5 M NaCl. The optimal conditions for the formation of EBV DNA/EBNA-1 complexes were 50 to 150 mM NaCl and pH 6.0. A balanced equilibrium of EBNA-1 and pM765-10 was necessary to achieve both a high yield and specificity of EBV DNA/EBNA-1 complexes.

DNA vaccine against oncogenic hamster cells transformed by HPV16 E6/E7 oncogenes and the activated ras oncogene.

The capability of DNA to elicit anti-tumour immunity was studied using human papillomavirus type 16 (HPV16)-transformed Syrian hamster cells denoted K3/II. These cells had been derived after cotransfection of primary kidney cell cultures with p16HHMo plasmid containing E6/E7 oncogenes of HPV16 and pEJ6.6 plasmid containing the activated human H-ras oncogene; they express both the HPV16 and activated H-ras genes. As a DNA vaccine, the p16HHMo plasmid was used. Three doses of the plasmid (either 100 microg or 10-15 microg per dose) were administered intramuscularly at 3-week intervals. The animals were challenged with four different doses (10(3)-10(6) per animal) of K3/II cells 10 days after the last plasmid injection. In one experiment the lower dose of plasmid DNA was also given in a mixture with the cationic lipid DOTAP. In another experiment, the pEJ6.6 plasmid (100 microg per dose) was used either alone or in combination with p16HHMo. In all experiments animals inoculated with the same doses of pBR322 plasmid served as controls. A moderate protective effect was observed in animals inoculated with the 100-microg doses of p16HHMo, but not in those inoculated with 10-15 microg of the same plasmid, whether given with or without DOTAP. A protective effect was also observed after administration of the pEJ6. 6 plasmid. At the time of challenge a portion of the p16HHMo-immunized, but not the pBR322-treated, animals possessed antibodies reactive in ELISA with peptides derived from the N-terminal portion of HPV16 E7 protein and with one peptide derived from E6 protein, while two other E6 peptides exhibited non-specific reactivity.