Biomedical subjects
A G Dalgleish
Publications and source records attributed to A G Dalgleish.
The role of immunotherapy for urological tumours.
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Viruses and multiple sclerosis.
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Cancer biologists hit the road. Molecular genetics of cancer: Second Joint Conference of the American Association for Cancer Research and the European Association for Cancer Research. Oxford, UK, 9-13 September 1997. Cancer gene therapy symposium. London, UK, 23-24 June 1997.
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The use of 7-amino actinomycin D in identifying apoptosis: simplicity of use and broad spectrum of application compared with other techniques.
The detection and quantitation of apoptotic cells is becoming increasingly important in the investigation of the role of apoptosis in cellular proliferation and differentiation. The pathogenesis of hematologic disorders such as aplastic anemia and the development of neoplasia are believed to involve dysregulation of apoptosis. To quantitate accurately the proportion of apoptosis cells within different cell types of a heterogeneous cell population such as blood or bone marrow, a method is required that combines the analysis of large numbers of cells with concurrent immunophenotyping of cell surface antigens. In this study, we have evaluated such a method using the fluorescent DNA binding agent, 7-amino actinomycin D (7AAD), to stain three diverse human cell lines, induced to undergo apoptosis by three different stimuli. Flow cytometric analysis defines three populations on the basis of 7AAD fluorescence and forward light scatter. We have shown by cell sorting and subsequent morphological assessment and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling that the populations defined by 7AAD represent live, apoptotic, and late-apoptotic/dead cells. This method is quick, simple, reproducible, and cheap and will be a valuable tool in the investigation of the role of apoptosis in normal physiology and in disease states.
Cytokines and soluble receptor changes in the transition from primary to early chronic HIV type 1 infection.
We studied determinants of chronic inflammation and/or immune activation in plasma from patients in the transition from primary to early chronic HIV-1 infection. The following parameters were estimated in seven patients over time: plasma concentrations of soluble CD8 (sCD8), tumor necrosis factor alpha (TNF-alpha), soluble TNF receptor type II (sTNFRII), interleukin 6 (IL-6), soluble IL-6 receptor (sIL6R), IL-10, transforming growth factor beta1 (TGF-beta1), along with CD4- and CD8-positive T cell counts, p24 antigenemia, and clinical evaluation. Results showed that concentrations of sCD8, TNF-alpha, and sTNFRII, and peripheral CD8-positive lymphocyte counts, were significantly increased in patients, compared to HIV-negative controls, and showed a trend toward normal values over time. Levels of IL6, sIL6R, IL-10, and TGF-beta1 did not differ from those of controls and did not change over time. Heterogeneity was observed among the patients in terms of CD4-positive T cell depletion, levels of sCD8, concentrations of TNF-alpha/sTNFRII, and clinical outcome. These data indicate that in the transition phase from primary acute to chronic and asymptomatic infection the host immune activation in response to the virus is highly heterogeneous and that the sustained rise in TNF-alpha and its receptor may represent an important therapeutic target in early disease. The persistence of a state of chronic inflammation and/or immune activation could influence the progression of disease independently from CD4-positive T cell counts.
The role of host immune responses in determining the outcome of HIV infection.
The progression of disease following infection with human immunodeficiency virus (HIV) correlates with an activated immune system and would appear to depend to some degree on the immunogenetics of the host. Here, Michael Westby, Fabrizio Manca and Angus Dalgleish discuss the evidence for HLA determination of clinical outcome and the potential implications of a restricted T-cell receptor repertoire for pathogenesis.
A phase II study of continuous-infusion 5-fluorouracil with cisplatin and epirubicin in inoperable pancreatic cancer.
Carcinomas of the exocrine pancreas respond poorly to most chemotherapy regimens. Recently continuous infusional 5-fluorouracil (200 mg m-(2)day-1) with 3 weekly cisplatin (60 mg m-2) and epirubicin (50 mg m-2) (the ECF regimen) has proven to be an active regimen in gastric and breast cancer and consequently worthy of further study in pancreatic cancer. Thirty-five patients were treated with the ECF regimen as above, of whom 29 were evaluable for response and 32 were evaluable for toxicity. The mean age was 59 years (range 37-75). Sixteen patients had locally advanced disease at presentation and 19 had metastases. Objective tumour responses were documented in five (17.3%) patients who achieved a partial response; in 18 (62%) patients there were no change and six (20.7%) patients progressed on therapy. Patients with either stable disease or partial response had a significantly improved overall survival (median = 253 days) compared with patients who progressed (median = 170 days; P = 0.01). Grade 3/4 (WHO) toxicity (all cycles) included alopecia in 18 (56%) patients, nausea/vomiting in eight (25%) stomatitis in three (9%) and diarrhoea in seven (22%) patients, with rhinorrhoea and excessive lacrimation in one patient each. Neutropenic sepsis occurred in 13 cycles in ten patients, and there was one toxic death due to sepsis. There were eight other episodes of non-neutropenic sepsis requiring hospital admission. Fourteen patients (40%) experienced complications with their Hickman lines, including thrombotic episodes (six patients) or their line falling out (five patients). ECF can prolong survival in patients with locally advanced or metastatic pancreatic cancer who demonstrate a response or stabilisation of their disease. However, this is associated with considerable toxicity.
An alternative to 51Cr release assay for measurement of natural killer activity in HIV-infected patients.
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Interleukin-10-induced HIV-1 expression is mediated by induction of both membrane-bound tumour necrosis factor (TNF)-alpha and TNF receptor type 1 in a promonocytic cell line.
OBJECTIVE: To investigate whether the upregulatory effect of interleukin (IL)-10 on HIV expression in a model of latent HIV infection is mediated by induction of endogenous tumour necrosis factor (TNF)-alpha and TNF receptors (TNFR). DESIGN: The latently HIV-infected promonocytic cell line U1 was examined, because in this in vitro model IL-10 has been shown to synergize with multiple cytokines, including TNF-alpha, in enhancing HIV production. METHODS: Membrane-bound TNF-alpha, TNFR-1 and TNFR-2 surface expression were determined by flow cytometry. TNF-alpha mRNA was estimated by competitive polymerase chain reaction (PCR), and TNF-alpha, soluble TNFR-1 and soluble TNFR-2 supernatant content by enzyme-linked immunosorbent assay. HIV-1 expression was quantitated by reverse transcriptase assay and p24 antigen release. RESULTS: We demonstrated that IL-10 induces a time and cell-concentration dependent upregulation of HIV expression in U1 cells. This effect is mediated through the endogenous production of TNF-alpha as demonstrated by blocking experiments with anti-TNF-alpha antibodies and by detection of IL-10-induced increase of TNF-alpha mRNA by competitive PCR. More importantly, IL-10 is able to upregulate membrane-bound TNF-alpha and TNFR-1, along with a consistent increase in the shedding of soluble TNFR-1 without inducing detectable TNF-alpha secretion. CONCLUSIONS: IL-10 activates HIV expression through the membrane-bound TNF-alpha/TNFR-1 pathway, suggesting an amplification mechanism of HIV expression that might occur during cell-to-cell interaction. This positive regulatory effect of IL-10 in an in vitro model of chronic HIV infection is consistent with the inexorable progression of disease seen in advanced patients when both IL-10 and TNF-alpha are elevated.
Allogeneic murine melanoma cell vaccine: a model for the development of human allogeneic cancer vaccine.
In an attempt to induce an immune response against tumour antigens, several groups are transfecting cytokine and other genes into autologous tumour cells which are given to the patient as a vaccine. This process is labour-intensive, time-consuming and expensive. Allogeneic cells would offer a more convenient vehicle for the delivery of cytokines and other molecules. However, current dogma suggests that MHC-matched cells are a prerequisite for an effective immune response. Using murine melanoma models we compared allogeneic and autologous vaccination and showed that the survival of C56BL/6 mice (H-2b) was prolonged with some degree of protection achieved against an autologous B15-F10 (H-2b) cell challenge when the mice were vaccinated with allogeneic K1735-M2 (H-2k) cells but not when immunized with autologous B16-F10 cells. Both vaccination with live and irradiated allogeneic cells induced an anti-tumour effect using only one immunization and no boost or adjuvant. Protection was not observed after vaccination with another melanoma (S91; H-2d) or with a carcinoma (A9HT; H-2k). Allogeneic vaccination promoted a cytotoxic cellular response against both the allogeneic and the syngeneic melanomas. This allogeneic vaccination model will be useful for studying the underlying mechanisms of protection, in both pre- and post-challenge settings, as well as for developing whole cell vaccination systems using genetically modified allogeneic tumour cells.
Abnormal cytokine profiles in patients with idiopathic dilated cardiomyopathy and their asymptomatic relatives.
OBJECTIVES: Immunological abnormalities in idiopathic dilated cardiomyopathy (DCM) include an increase in soluble interleukin (IL)-2 receptor, disease specific cardiac autoantibodies, an HLA-DR4 association, and familial aggregation of disease; however, cytokine profiles have not been defined. Serum concentrations of IL-2, IL-4, IL-10, and IL-12 were measured in patients with DCM (WHO criteria), relatives with asymptomatic left ventricular enlargement (LVE), patients with ischaemic heart failure (IHD), and healthy controls. DESIGN: Serum from 20 individuals from each of the four groups was assayed for cytokine concentrations by a commercial enzyme linked immunosorbent assay. RESULTS: IL-2 concentrations were abnormally increased in DCM patients and relatives with LVE. Concentrations of IL-10 were increased in DCM patients. Concentrations of IL-4 and IL-12 were not increased in any of the groups. CONCLUSION: These abnormalities may reflect defective/inappropriate T cell function in patients with DCM and in their relatives with LVE.
The development of therapeutic vaccines of the management of malignant melanoma.
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Gene therapy for prostate cancer.
Prostate cancer is one of the leading causes of cancer deaths in the Western world and current therapies are of limited efficacy in advanced disease. Both ex vivo and in vivo gene therapy strategies offer exciting new possible approaches to the management of this disease. Ex vivo gene therapy involving interleukin-2 or granulocyte-macrophage colony-stimulating factor transduced whole tumour cell vaccines has shown great promise in animal models. The feasibility of in vivo corrective gene therapy involving the replacement of mutant tumour suppressor genes, antisense strategies and the insertion of suicide genes has been demonstrated in preclinical models. Several of these therapies are now entering phase I/II studies in patients with prostate cancer.
Comparison of IL-2- and IL-4-transfected B16-F10 cells with a novel oil-microemulsion adjuvant for B16-F10 whole cell tumour vaccine.
The use of whole cell tumour vaccines in the treatment of malignant melanoma has given mixed results. Cytokine-transfected tumour cells as vaccine have shown efficacy in animal models but need to be compared with other means of enhancing a systemic anti-tumour immune response. A new generation of immunological adjuvants claimed to be more effective than the conventional adjuvants is now available for assessment. We have investigated the action of an oil-microemulsion adjuvant formulation (IDEC antigen formulation (IDEC-AF)) in the B16-F10 murine melanoma model. After standardisation of the whole cell tumour vaccination protocol we showed that mice vaccinated with whole irradiated cells combined with IDEC-AF produced a significant inhibition of tumour growth, following a challenge with live tumour cells, when compared with mice vaccinated with whole cell vaccine alone. IDEC-AF was superior to two conventional adjuvants, namely alum and incomplete Freund's adjuvant and a more reliable response was achieved with the oil-microemulsion adjuvant compared with IL-2-transfected cells. In addition, the adjuvant was comparable in efficacy to IL-4-transfected B16-F10 cells. Given the practical difficulty in using cytokine-transfected tumour cells and the limited therapeutic range of some cytokines, a cheap and easy to deliver adjuvant formulation proved equally or more effective than some of the currently clinically used transfected cytokines.
Chemotherapy for solid tumours.
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The immune response to HIV: potential for immunotherapy?
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