Heat shock proteins refine the danger theory.
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Apoptosis↗
Biomedical subjects
A G Dalgleish
Publications and source records attributed to A G Dalgleish.
Allogeneic whole-tumour cell vaccination in the rat model of prostate cancer.
OBJECTIVE: To investigate cancer immunotherapy using whole allogeneic (differing tissue-type) tumour cells as vaccines in the rat prostate cancer model. Materials and methods Two rat models of prostate cancer were used; MAT-LyLu tumours which grow in Copenhagen rats and PAIII tumours which grow in Lobund-Wistar rats, with crossover of the cell lines to test allogeneic vaccination. The cell lines were immunologically characterized by flow cytometry. Irradiated tumour cells were administered as subcutaneous vaccines either before tumour challenge or after tumour establishment (both subcutaneous). A preparation of heat-killed Mycobacterium vaccae bacilli (SRL172) was used as an adjuvant to increase vaccine efficiency. RESULTS: Flow cytometry analysis of the cell lines showed that the PAIII cells had higher levels of major histocompatibility complex (MHC) class I and intercellular adhesion molecule (ICAM-1) expression than the MAT-LyLu cells. However, both tumour cell lines were rejected in their allogeneic hosts. Prophylactic vaccination with allogeneic MAT-LyLu cells protected against PAIII tumour challenge in Lobund-Wistar rats, with 80% of animals surviving for > 5 months, compared with 40% for animals receiving autologous cells. The immunity was prolonged, as rats were protected when rechallenged 5 months later. In Copenhagen rats allogeneic PAIII cells protected against the more aggressive MAT-LyLu tumour challenge only when the cells were combined with SRL172. Initial therapy experiments showed that vaccination with the cell lines mediated only limited tumour regression in the Lobund-Wistar rats. CONCLUSION: The allogeneic tumour cell vaccination model described is valuable for assessing the principle and efficacy of allogeneic prostate cancer cell vaccines for clinical use.
Animals↗
Reduction in cytokine production in colorectal cancer patients: association with stage and reversal by resection.
The aim of this study was to assess monocyte/macrophage function, as defined by lipopolysaccharide (LPS)-induced production of tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and interferon (IFN)-gamma by stimulated whole blood cultures in patients with colorectal carcinoma before and after surgical resection. Forty colorectal cancer patients prior to surgery and 31 healthy controls were studied. Heparinized venous blood was taken from colorectal cancer patients prior to surgery and from healthy controls. Serial samples were obtained at least 3-6 weeks post-operatively. Blood was stimulated with LPS for 24 h and supernatants were assayed for TNF-alpha, IFN-gamma and IL-10 by enzyme-linked immunosorbent assay. LPS-induced production of TNF-alpha and of IFN-gamma was reduced in patients with colorectal carcinoma compared to controls (TNF-alpha, 11,269 pg/ml(-1) ¿12,598¿; IFN-gamma, 0.00 pg/ml(-1) ¿226¿; median ¿IQR¿) (TNF-alpha, 20,576 pg/m(-1) ¿11,637¿, P < 0.0001; IFN-gamma, 1,048 ¿2,428¿, P = 0.0051, Mann-Whitney U-test). Production in patients after surgery had increased (TNF-alpha: 17,620 pg/ml(-1) ¿7,986¿; IFN-gamma. 410 pg/ml(-1) ¿2,696¿; mean ¿s.d.¿) and were no longer significantly reduced when compared to controls (TNF-alpha, P = 0.28; IFN-gamma, P = 0.76). Production of TNF-alpha and IFN-gamma prior to surgery were reduced to a greater extent in patients with Dukes' stage C tumours compared to those with Dukes' stage A and B stage. There was no difference in IL-10 production between any group. Monocytes/macrophages from patients with colorectal carcinoma are refractory to LPS stimulation as reflected by reduction in TNF-alpha and IFN-gamma production and this is more pronounced in patients with advanced stage tumours. This suppression is not mediated by IL-10 and disappears following surgical resection of the tumour. This provides evidence for tumour induced suppression of immune function in patients with colorectal cancer and identifies a potential therapeutic avenue.
Aged↗
Differential and antagonistic effects of 9-cis-retinoic acid and vitamin D analogues on pancreatic cancer cells in vitro.
Retinoids and vitamin D are known to exert important anti-tumour effects in a variety of cell types. In this study the effects of 9-cis-retinoic acid (9cRA) the vitamin D analogues EB1089 and CB1093 on three pancreatic adenocarcinoma cell lines were investigated. All compounds caused inhibition of in vitro growth but the vitamin D analogues were generally the more potent growth inhibitors. They were also more effective on their own than in combination with 9cRA. Growth arrest correlated with an increased proportion of cells in the G0/G1 phase. Apoptosis was induced in the three cell lines by 9cRA, whereas neither EB1089 nor CB1093 had this effect. Furthermore, addition of EB1089 or CB1093 together with 9cRA resulted in significantly reduced apoptosis. Our results show that retinoic acids as well as vitamin D analogues have inhibitory effects on pancreatic tumour cells but different and antagonistic mechanisms seem to be employed.
Alitretinoin↗
HIV gp120 plus specific peptides are recognized in a similar manner to specific HLA plus peptide by HLA-restricted antigen-specific T-cell lines.
HIV induces disease only following chronic activation of the immune system. Other retroviruses such as the mouse mammary tumour virus (MMTV) activate a large percentage of T cells by encoding a superantigen (SAg). To date there is no evidence that HIV encodes a SAg. An alternative way to induce pan-activation of the immune system is by allogeneic stimulation, which occurs following transplantation. Here we extend previous work which demonstrated that HIVpg120 could bind peptides in a similar manner to HLA, by demonstrating that human antigen presenting cells (APCs) expressing gp120 (but not DR1) can present a DR1-restricted peptide to induce proliferation of a DR1-restricted peptide-specific T-cell line in a similar manner to the same peptide presented by a DR1 expressing APC. Our data provide strong support for the hypothesis that the HLA-like regions of gp120 encode functional properties shared with HLA, and could explain the extraordinary clinical and immunological similarities between AIDS and chronic graft versus host disease.
Animals↗
Detection of T cell cytokine production as a tool for monitoring immunotherapy.
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Cytokines↗
DNA vaccines.
The premise that DNA coding for antigens produces proteins to stimulate the immune system when inoculated directly into muscle tissues, has the immense attractions of simplicity, versatility and economy. When other vaccination approaches are experiencing practical problems, meeting such challenges as AIDS and malaria, considerable attention has focused on DNA vaccines with entire conferences and a flood of commercial companies devoted to exploring the possibilities. A number of clinical trials for both infectious diseases and cancer have already commenced, even though a number of major issues have to be resolved.
Acquired Immunodeficiency Syndrome↗
Prospects for vaccination in prostate cancer.
Prostate cancer continues to be a major cause of morbidity and mortality. Surgical and medical management of the disease has improved but there is little effect upon overall survival. Novel therapies such as immunotherapy offer the potential of treating the disease by stimulating the immune system to mount a response to the cancer systemically. This review highlights the pitfalls and progress in the understanding of the role of the immune system in malignancy and also explains the theory behind prostate cancer vaccine trials.
Antigen Presentation↗
Potential applications of gene therapy in the patient with cancer.
The elderly population has much to gain from the advances of molecular medicine, although at present genetic pharmacology remains mostly at the conceptual level. Cancer, in particular, is an increasing health burden and the majority (over 70%) of gene therapy trials are aimed at tackling this problem. Available strategies employ both viral and synthetic vectors with the selective delivery and expression of therapeutic genes a pivotal requirement. Clinical trials are now in progress with a view to modulating disease at many different levels, including the direct replacement of abnormal genes. suicide-gene formulations, and the delivery of 'gain of function' genes, which seek to alter the malignant phenotype by indirect means, such as, immunopotentiation and stromal reorganisation. Early data from these studies is tantalising and we must remain optimistic that gene therapy will benefit the patient with cancer by both reducing morbidity and extending life.
Aged↗
Phase I study of ONO-4007, a synthetic analogue of the lipid A moiety of bacterial lipopolysaccharide.
ONO-4007 is a synthetic analogue of the lipid A moiety of bacterial lipopolysaccharide, which exhibits antitumor activity by the induction of intratumoral tumor necrosis factor alpha, the potentiation of tumor-infiltrating macrophages, and the inhibition of angiogenesis. Interleukin (IL)-1 alpha, IL-6, and IL-12 induction by ONO-4007 activates cytotoxic natural killer cells to up-regulate IFN-gamma and nitric oxide synthase activity. ONO-4007 was given to 24 patients (13 males and 11 females; median age, 53 years) as a 30-min i.v. infusion on day 1, followed on day 15 by a first treatment cycle consisting of three weekly infusions at the same dose, followed by a rest period of 1 week. Cohorts of six patients received up to a maximum of four treatment cycles at increasing dose levels (75, 100, and 125 mg). The maximum tolerated dose was 125 mg, with grade 3 National Cancer Institute Common Toxicity Criteria toxicity (rigors with cyanosis) occurring in two of six patients at this dose level. An additional six patients were treated at 100 mg, the dose below the maximum tolerated dose. Other toxicities included grade 2 National Cancer Institute Common Toxicity Criteria myalgia, nausea, and hypotension. The pharmacokinetics of ONO-4007 appeared to be independent of dose and showed linearity with respect to time. ONO-4007 has a low systemic clearance (approximately 1.3 ml/min) and a small volume of distribution (5-8 liters) with a long t1/2 of 74-95 h. The administration of ONO-4007 was shown to result in a significant increase in circulating levels of tumor necrosis factor alpha and IL-6. No objective antitumor responses were observed. Seven patients maintained stable disease for at least two cycles, whereas five patients maintained stable disease for the full four-cycle duration of the study. Additional studies are required to determine the antitumor activity of ONO-4007.
Adult↗
Oncological applications of gene therapy.
Despite the rapid technological advances that continue to sustain the field of cancer gene therapy, few individual patients have benefited from the revolution so far. The plethora of clinical trials described confirms that each malignancy will have its own ideal strategy based on the associated molecular defects, and there has been rapid progress from this viewpoint. At the same time, there has been a renewed appreciation for the limitations to gene therapy, which include low efficiency of gene transfer, poor specificity of response and methods to accurately evaluate responses, and lack of truly tumor-specific targets at which to aim. As with all new therapies, we are climbing a steep learning curve in terms encountering treatment-related toxicities, as well as profound ethical and regulatory issues.
Animals↗
Gene therapy: recent progress in the clinical oncology arena.
Despite the rapid technological advances that continue to sustain the field of cancer gene therapy, few individual patients have benefited from the revolution so far. The plethora of clinical trials described confirms that each malignancy will have its own ideal strategy based on the associated molecular defects, and there has been rapid progress from this viewpoint. At the same time, there has been a renewed appreciation for the limitations to gene therapy, which include low efficiency of gene transfer, poor specificity of response and methods to accurately evaluate responses, and lack of truly tumor-specific targets at which to aim. As with all new therapies, we are climbing a steep learning curve in terms encountering treatment-related toxicities, as well as profound ethical and regulatory issues.
Animals↗
Immunotherapy with Mycobacterium vaccae.
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Combined Modality Therapy↗
The gp120 envelope of HIV-1 binds and presents peptides in a similar manner to human leukocyte antigen.
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Antigen Presentation↗
The role of HIV gp120 in the disruption of the immune system.
The existence of HIV positive individuals who do not appear to progress to disease, or do so only very slowly (LTNPs), strongly suggest that factors other than virus pathogenicity determine disease. The occurence of HIV infected chimpanzees that remain disease free and other African SIV infected primates where disease is apparently species specific underscores the importance of host factors [1,2]. We have examined the immune response of LTNP patients using a variety of techniques including intracellular cytokine FACscan, anchor PCR analysis of the T cell receptor and HLA typing of class II genes by DNA sequencing. Our results to date confirm that the development of disease is consistent with activation of a susceptible immune system, and that this could be due to the fact that HLA-like sequences of HIV may 'allo' activate the host immune response. In order to test this hypothesis further we have examined whether gp120 itself can bind and present specific peptides which may be capable of eliciting 'allo' activation responses in particular hosts.
Antigen Presentation↗
Thalidomide as an emerging immunotherapeutic agent.
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Abnormalities, Drug-Induced↗
Possible improved survival of patients with stage IV AJCC melanoma receiving SRL 172 immunotherapy: correlation with induction of increased levels of intracellular interleukin-2 in peripheral blood lymphocytes.
PURPOSE: This phase I-II study was designed to assess safety and clinical efficacy of SRL 172 vaccine in patients with advanced stage IV (AJCC) malignant melanoma. Induction of intracellular cytokines (IL-2 and INF-gamma) in peripheral blood lymphocytes (PBLCs) from these patients was assayed and correlated to clinical outcome. PATIENTS AND METHODS: SRL 172 was administered intradermally to 24 patients with stage IV malignant melanoma, initially at 15-day intervals for three vaccinations and then at monthly intervals. Lymphocyte activation for cytokines in PBLCs was assayed prior to each vaccine administration using a FACS-based intracellular cytokine assay. Survival was compared to historical controls. RESULTS: The vaccination schedule resulted in sustained intracellular IL-2 induction in PBLCs in 9 of 23 patients (39%) who received at least three doses. Cytokine induction became apparent within the first three administrations of vaccine and was maximal at 8-12 weeks. Induction of intracellular IL-2 production (group 1) was associated with improved survival (P < 0.036). The median survival of the nine patients demonstrating IL-2 induction was 59 (95% confidence interval (95% CI): 47-71) weeks compared to 31 (95% CI: 18-44) weeks for the non-inducers. Induction of INF-gamma (group 2) was found in 10 patients and 6 patients had IL-2 and INF-gamma induction (group 3). There was no survival advantage for these patient groups. Although no objective responses were documented the group as a whole had a median survival of 44 (95% CI: 31-59) weeks which is better than that of historical controls. SRL 172 was safe and well tolerated. CONCLUSION: SRL 172 is effective in inducing intracellular IL-2 responses in PBLCs of a significant number of patients with stage IV (AJCC) melanoma. This is correlated with improved survival. The survival analysis is sufficiently encouraging to suggest that further prospective trials are justified. The methodology we present in this study may help in developing surrogate markers that will allow rational immunotherapeutic strategies to be designed for cancer patients.
Cancer Vaccines↗