Evaluation of the utility and reliability of COSHH Essentials.
Explore the source record for details and available documents.
Hazardous Substances↗
Biomedical subjects
Heather Jackson
Publications and source records attributed to Heather Jackson.
Striking immunodominance hierarchy of naturally occurring CD8+ and CD4+ T cell responses to tumor antigen NY-ESO-1.
Immunodominance has been well-demonstrated in many antiviral and antibacterial systems, but much less so in the setting of immune responses against cancer. Tumor Ag-specific CD8+ T cells keep cancer cells in check via immunosurveillance and shape tumor development through immunoediting. Because most tumor Ags are self Ags, the breadth and depth of antitumor immune responses have not been well-appreciated. To design and develop antitumor vaccines, it is important to understand the immunodominance hierarchy and its underlying mechanisms, and to identify the most immunodominant tumor Ag-specific T cells. We have comprehensively analyzed spontaneous cellular immune responses of one individual and show that multiple tumor Ags are targeted by the patient's immune system, especially the "cancer-testis" tumor Ag NY-ESO-1. The pattern of anti-NY-ESO-1 T cell responses in this patient closely resembles the classical broad yet hierarchical antiviral immunity and was confirmed in a second subject.
Animals↗
Transforming growth factor-beta1-induced endothelial barrier dysfunction involves Smad2-dependent p38 activation and subsequent RhoA activation.
Lung edema due to increased vascular permeability is a hallmark of acute lung injury and acute respiratory distress syndrome. Both p38 and RhoA signaling events are involved in transforming growth factor (TGF)-beta1-increased endothelial permeability; however, the mechanism by which these pathways cooperate is not clear. In this study, we hypothesized that TGF-beta1-induced changes in endothelial monolayer permeability and in p38 and RhoA activation are dependent on Smad2 signaling. We assessed the role of Smad2 in p38 activation and the role of p38 in RhoA activation by TGF-beta1. We found that TGF-beta1 caused Smad2 phosphorylation between 0.5 and 1 h of exposure in endothelial cells. Knockdown of Smad2 protein prevented TGF-beta1-induced p38 activation and endothelial barrier dysfunction. Furthermore, TGF-beta1-enhanced RhoA activation was dependent on p38 activation. Inhibition of the RhoA-Rho kinase signaling pathway blunted TGF-beta1-induced adherens junction disruption and focal adhesion complex formation. In addition, depletion of heat shock protein 27, a downstream signaling molecule of p38, did not prevent TGF-beta1-induced endothelial barrier dysfunction. Finally, inhibition of de novo protein expression blunted TGF-beta1-induced RhoA activation and endothelial barrier dysfunction. Our data indicate that TGF-beta1 induces endothelial barrier dysfunction involving Smad2-dependent p38 activation, resulting in RhoA activation by possible transcriptional regulation.
Animals↗
Characterization of antigen-specific CD8+ T lymphocyte responses in skin and peripheral blood following intradermal peptide vaccination.
Immune responses to cancer vaccines are commonly tested by measuring cutaneous reactions to intradermal (i.d.) antigen. When well-characterized peptide epitopes are injected i.d., infiltrates of CD4+ and CD8+ T lymphocytes are frequently seen. In this study, we have further characterized T cells derived from vaccine-infiltrating lymphocyte (VIL) responses. We found that the infiltrates capable of producing IFN-gamma and cytolytic activity could recognize vaccine peptide, as well as antigen-positive melanoma cells. We studied antigen-specific T cell responses from VILs and peripheral blood in 10 patients who participated in a clinical trial. All patients received systemic Flt3 ligand (20 microg/kg/d) and i.d. peptides: Three NY-ESO-1 peptides, SLLMWITQCFL (157-167), SLLMWITQC (157-165), QLSLLMWIT (155-163); tyrosinase internal peptide YMDGTMSQV (368-376); Melan-A/MART-1 analogue peptide ELAGIGILTV (26-35, E27L substitution); and influenza matrix peptide GILGFVFTL (58-66). In 54 paired VIL and peripheral blood analyses, a good correlation was found between responses in skin and in blood. These cells could be rapidly expanded in a short-term assay and thus appear to be memory T cells. The demonstrated presence of antigen-specific T cells at vaccination sites validates this method of assessing the immune response to i.d. vaccines.
Antigens, Neoplasm↗
The impact of imiquimod, a Toll-like receptor-7 ligand (TLR7L), on the immunogenicity of melanoma peptide vaccination with adjuvant Flt3 ligand.
Dendritic cells (DCs) show promise as adjuvants in anticancer immunotherapeutic strategies. Flt3 ligand (FL) is a hematopoietic growth factor that increases the number of immature DCs in the blood and other tissues. We treated 27 patients with metastatic or high-risk resected melanoma with s.c. FL daily for 14 d in three 28 d cycles. Eighteen of these patients also received vaccination with influenza (Flu), Melan-A (Mel), tyrosinase (Tyr), and NY-ESO-1 peptides. To induce local DC maturation, 8 of the vaccinated patients had imiquimod, a Toll-like receptor-7 ligand (TLR7L), applied topically to their vaccine sites. Patients were monitored for clinical and hematological effects. Immune responses were assessed by cutaneous reactivity to vaccination and by the induction of peptide-specific CD8+ T-cells. Eight patients did not complete the protocol due to adverse events related to their cancer. The treatment was generally safe and well tolerated, although some patients developed clinically significant toxicities related to FL. FL induced increases in immature CD11c+ and CD123+ peripheral blood (PB) DCs. Other hematological effects included monocytosis, granulocytosis, and thrombocytosis, which were marked in some patients. Cutaneous reactions to peptide vaccination and circulating peptide-specific CD8+ T-cells were more frequent in imiquimod-treated patients. FL treatment of melanoma patients has pleiotropic clinical and hematological effects. In vivo maturation of FL-generated DCs using imiquimod may increase immune responses to tumor antigens.
Adjuvants, Immunologic↗
Recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant induces broad integrated antibody and CD4(+) and CD8(+) T cell responses in humans.
NY-ESO-1 is a "cancer-testis" antigen expressed in many cancers. ISCOMATRIX is a saponin-based adjuvant that induces antibody and T cell responses. We performed a placebo-controlled clinical trial evaluating the safety and immunogenicity of recombinant NY-ESO-1 protein with ISCOMATRIX adjuvant. Forty-six evaluable patients with resected NY-ESO-1-positive tumors received three doses of vaccine intramuscularly at monthly intervals. The vaccine was well tolerated. We observed high-titer antibody responses, strong delayed-type hypersensitivity reactions, and circulating CD8(+) and CD4(+) T cells specific for a broad range of NY-ESO-1 epitopes, including known and previously unknown epitopes. In an unplanned analysis, vaccinated patients appeared to have superior clinical outcomes to those treated with placebo or protein alone. The vaccine is safe and highly potent immunologically.
Adjuvants, Immunologic↗
Immunodominant CD4+ responses identified in a patient vaccinated with full-length NY-ESO-1 formulated with ISCOMATRIX adjuvant.
There is increasing evidence showing the involvement of CD4(+) T cells in initiating and maintaining antitumor immune responses. NY-ESO-1 is expressed by various tumors but not normal tissues except testis. We conducted a cancer clinical trial by using full-length NY-ESO-1 protein formulated with ISCOMATRIX adjuvant and injected into patients intramuscularly. Autologous dendritic cells pulsed with NY-ESO-1 ISCOMATRIX in combination with overlapping synthetic peptides were used to identify immunodominant T cells from a vaccinated patient. We show here the identification and characterization of two novel CD4(+) T cell epitopes. T cells specific to these epitopes not only recognized autologous dendritic cells loaded with NY-ESO-1 but also NY-ESO-1-expressing tumor cell lines treated with IFN-gamma. One of the two responses identified was greater than the previously identified immunodominant HLA-DP4-restricted response and correlated with NY-ESO-1-specific CD8(+) T cell induction after vaccination. This T cell response was vaccinated in most patients who expressed HLA-DR2. This study has systematically surveyed patients vaccinated with full-length tumor antigen for a vaccinated CD4 helper T cell response.
Amino Acid Sequence↗
Functional and structural characteristics of NY-ESO-1-related HLA A2-restricted epitopes and the design of a novel immunogenic analogue.
NY-ESO-1, a commonly expressed tumor antigen of the cancer-testis family, is expressed by a wide range of tumors but not found in normal adult somatic tissue, making it an ideal cancer vaccine candidate. Peptides derived from NY-ESO-1 have shown preclinical and clinical trial promise; however, biochemical features of these peptides have complicated their formulation and led to heterogeneous immune responses. We have taken a rational approach to engineer an HLA A2-restricted NY-ESO-1-derived T cell epitope with improved formulation and immunogenicity to the wild type peptide. To accomplish this, we have solved the x-ray crystallographic structures of HLA A2 complexed to NY-ESO (157-165) and two analogues of this peptide in which the C-terminal cysteine residue has been substituted to alanine or serine. Substitution of cysteine by serine maintained peptide conformation yet reduced complex stability, resulting in poor cytotoxic T lymphocyte recognition. Conversely, substitution with alanine maintained complex stability and cytotoxic T lymphocyte recognition. Based on the structures of the three HLA A2 complexes, we incorporated 2-aminoisobutyric acid, an isostereomer of cysteine, into the epitope. This analogue is impervious to oxidative damage, cysteinylation, and dimerization of the peptide epitope upon formulation that is characteristic of the wild type peptide. Therefore, this approach has yielded a potential therapeutic molecule that satiates the hydrophobic F pocket of HLA A2 and exhibited superior immunogenicity relative to the wild type peptide.
Adult↗
Risk factors for elevated intraocular pressure in uveitis.
PURPOSE: To determine the prevalence of raised intraocular pressure (IOP) in patients with uveitis and to identify risk factors for raised IOP in patients with uveitis. PATIENTS AND METHODS: Consecutive case notes of 257 patients (402 eyes) attending a specialist uveitis clinic during a three-month period were reviewed. Patients with raised IOP were identified and further evaluated. Risk factors for raised IOP were determined. RESULTS: The prevalence of raised IOP in the study eyes was 41.8%. The prevalence of raised IOP requiring treatment was 29.8%. Raised IOP was found in 26.0% of eyes with acute uveitis and 46.1% of eyes with chronic uveitis. This difference was significant (P = 0.002). Similarly the prevalence of raised IOP requiring treatment in acute and chronic uveitis was 15.1% and 33.8%, respectively. This difference was also significant (P = 0.002). Active inflammation was significantly associated with raised IOP (P = 0.031). Steroid usage, increasing age, and number of years since diagnosis were significantly correlated with raised IOP (P = 0.008, P = 0.022, and P = 0.006, respectively); 9.6% of the study eyes developed glaucoma. The majority of these eyes (69.7%) were treated medically. The remainder (30.3%) required both medical and surgical management. CONCLUSION: Raised IOP is significantly more common in patients with chronic intraocular inflammation than those with acute uveitis. Risk factors for elevated IOP that should enable closer monitoring of 'at-risk' eyes have been identified.
Acute Disease↗
Choroidal neovascularization following hyperopic LASIK surgery.
Laser in situ keratomileusis (LASIK) is a well-accepted refractive surgical procedure; however, reports of complications of hyperopic surgery are scarce. This is the first report of bilateral macular choroidal neovascular membrane following bilateral hyperopic LASIK surgery. It highlights important considerations in older patients undergoing the procedure.
Choroidal Neovascularization↗
Two phase I studies of low dose recombinant human IL-12 with Melan-A and influenza peptides in subjects with advanced malignant melanoma.
Preclinical studies have shown that low dose IL-12 can potentiate cytotoxic lymphocyte responses. Since previous trials have demonstrated significant toxicity from high dose recombinant human IL-12 (rhIL-12), we sought to determine an optimal biological dose for rhIL-12 at lower doses when combined with peptide antigens. Two studies were undertaken. The rhIL-12 was administered at doses of 0 (placebo), 10, 30 and 100 ng/kg, subcutaneously in one study and intravenously in the other. Apart from IL-12 dosing, the studies were identical. Subjects had evaluable stage III or IV melanoma which expressed Melan-A by RT-PCR or immunohistochemistry. Melan-A (26-35) (EAAGIGILTV) and influenza matrix (58-66) (GILGFVFTL) peptides were administered intradermally on weeks 1, 2, 3, 4 and 9. Twenty-eight subjects were enrolled, of whom 24 were evaluable for clinical and immunological responses. Therapy was well tolerated, the main adverse event being influenza-like symptoms. Immunological monitoring included the evaluation of cutaneous reactions and assays for antigen-specific T-cells. Clinical responses included a complete response in a subject with small volume subcutaneous disease, a partial response in a subject with hepatic metastases, and mixed responses in pulmonary, pleural and nodal disease. Biopsies of accessible tumors showed infiltration with CD4+ and CD8+ lymphocytes capable of lysing Melan-A peptide-pulsed targets in vitro. No clear dose-dependent effect of rhIL-12 could be determined. The rhIL-12 given either s.c. or i.v. was well tolerated at doses of 10-100 ng/kg. Clinical and immunological activity has been observed in this study where peptides were administered either with or without low dose rhIL-12.
Adjuvants, Immunologic↗
Blood dendritic cells generated with Flt3 ligand and CD40 ligand prime CD8+ T cells efficiently in cancer patients.
Flt3 ligand mobilizes dendritic cells (DCs) into blood, allowing generation in vivo of large numbers of DCs for immunotherapy. These immature DCs can be rapidly activated by soluble CD40 ligand (CD40L). We developed a novel overnight method using these cytokines to produce DCs for cancer immunotherapy. Flt3 ligand-mobilized DCs (FLDCs) were isolated, activated with CD40L, loaded with antigenic peptides from influenza matrix protein, hepatitis B core antigen, NY-ESO-1, MAGE-A4, and MAGE-A10, and injected into patients with resected melanoma. Three injections were given at 4-week intervals. Study end points included antigen-specific immune responses (skin reactions to peptides alone or peptide-pulsed FLDCs; circulating T-cell responses), safety, and toxicity. No patient had a measurable tumor. Six patients were entered. FLDCs were obtained, enriched, and cultured under Good Manufacturing Practice grade conditions. Overnight culture with soluble CD40L caused marked up-regulation of activation markers (CD83 and HLA-DR). These FLDCs were functional and able to stimulate antigen-specific T cells in vitro. No significant adverse events were attributable to FLDCs. Peptide-pulsed FLDCs caused strong local skin reactions up to 60 mm diameter with intense perivascular infiltration of T cells, exceeding those seen in our previous peptide-based protocols. Antigen-specific blood T-cell responses were induced, including responses to an antigen for which the patients were naive (hepatitis B core antigen) and MAGE-A10. MAGE-A10-specific T cells with a skewed T-cell receptor repertoire were detected in 1 patient in blood ex vivo and from tumor biopsies. Vaccination with FLDCs pulsed with peptides is safe and primes immune responses to cancer antigens.
Adult↗