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Biomedical subjects

A B Kay

Publications and source records attributed to A B Kay.

At least 19 recordsLinked to original sources
PubMed2006

Induction of interleukin-10 and suppressor of cytokine signalling-3 gene expression following peptide immunotherapy.

BACKGROUND: Allergen-derived (T cell epitope) peptides may be safer for immunotherapy than native allergen, as they do not cross-link immunoglobulin (Ig)E. However, HLA polymorphism results in multiple potential epitopes. Synthetic peptides of phospholipase (PL) A(2) were selected for a peptide vaccine, on the basis of binding affinity for commonly expressed HLA-DR molecules. OBJECTIVE: To evaluate treatment with an HLA-DR-based PLA(2) peptide vaccine in subjects with mild honeybee allergy in an open, controlled study. METHODS: Twelve volunteers with allergy to bee venom received nine intradermal injections of PLA(2) peptides, with six untreated subjects serving as controls. Outcome was assessed by the size of the late-phase cutaneous reaction to allergen, peripheral blood mononuclear cell (PBMC) proliferation, cytokine release, and expression of genes associated with immune regulation. RESULTS: Subjects receiving peptides showed a decrease in the magnitude of the late-phase cutaneous reaction to bee venom compared with controls (P=0.03). The proliferation of venom-stimulated PBMCs decreased in treated subjects compared with controls (P=0.01). Peptide treatment reduced the production of IL-13 by PLA(2)-stimulated PBMCs (P<0.01) and IFN-gamma (P<0.01), and increased the production of IL-10 (P=0.02). Transcription of the suppressor of cytokine signalling (Socs)3 gene was significantly increased following therapy. A transient, but modest, increase in allergen-specific IgG was also observed. CONCLUSION: HLA-DR-based T cell epitopes modify surrogate markers associated with successful immunotherapy and induction of immune regulation, supporting the concept that this form of treatment may be efficacious in human allergic disease.

Adult↗
PubMed2006

100 years of 'Allergy': can von Pirquet's word be rescued?

Summary It is 100 years since Clemens von Pirquet wrote his classic paper introducing the term 'allergy'. Although the word is no longer used in the way he intended, his concept of 'changed reactivity' laid the foundation for the modern science of immunology.

Allergens↗
PubMed2005

Fel d 1-derived T cell peptide therapy induces recruitment of CD4+ CD25+; CD4+ interferon-gamma+ T helper type 1 cells to sites of allergen-induced late-phase skin reactions in cat-allergic subjects.

BACKGROUND: Specific immunotherapy with whole allergen extracts is associated with local accumulation of IFN-gamma+ and CD25+ cells indicating recruitment of activated T-helper type 1 (Th1) and/or T regulatory cells. We have studied allergen-induced, late-phase skin biopsies before and after T cell peptide therapy for evidence of alterations in the pattern of local recruitment of Th1, T-helper type 2 (Th2) and T regulatory cells. OBJECTIVE: To evaluate the effect of T cell peptide therapy on the allergen-induced cutaneous late-phase reaction. METHODS: Increasing doses of synthetic Fel d 1-derived peptides were administered (by intradermal injection) to eight cat-allergic asthmatics at 14-day intervals. Twenty-four-hour skin biopsies were taken from whole cat allergen- and diluent-injected sites, before and after treatment and studied by immunohistochemistry and in situ hybridization. RESULTS: Fel-d 1 peptides decreased airway hyper-responsiveness (P = 0.02) and inhibited the late-phase cutaneous reaction (LPCR) to whole cat allergen (P = 0.03). This was associated with significant increases (post- vs. pre-treatment) in the number of cutaneous CD4+/IFN-gamma+ (P = 0.03) and CD4+/CD25+ cells (P = 0.04), but not in CD4+/IL-10+ or CD4+/CTLA-4+ cells. CONCLUSIONS: Treatment with allergen-derived T cell peptides results in allergen-dependent recruitment to the skin of Th1, rather than T regulatory cells, to cutaneous late-phase reaction sites.

Animals↗
PubMed2005

The effect of Fel d 1-derived T-cell peptides on upper and lower airway outcome measurements in cat-allergic subjects.

BACKGROUND: We previously showed that overlapping Fel d 1-derived T-cell peptides inhibited surrogate markers of allergy (i.e. early and late-phase skin reactions and T-cell function) in cat allergic subjects. The present pilot study was designed to determine whether this treatment affected clinically relevant outcome measurements such as the allergen-induced nasal and bronchial reactions, and asthma/rhinitis quality of life (QOL). METHODS: Sixteen cat-allergic asthmatic subjects who gave a dual (early and late) asthmatic response (DAR) to inhaled cat allergen were randomly assigned to receive either Fel d 1 peptides (approximately 300 mug in increasing, divided doses) or placebo (8 active : 8 placebo). Twelve single early responders (SER) were also studied in an open fashion design. Allergen-induced bronchial and nasal measurements as well as the QOL was measured at baseline, 4-8 weeks (follow-up 1 (FU1)) and 3-4 months (FU2). RESULTS: In the active, but not placebo, group there were significant decreases in the late asthmatic reaction (LAR) to whole cat dander (P = 0.03) at FU2 but with no between group difference. There were also significant improvements in asthma quality of life (QOL) scores [asthma-activity limitation (P = 0.014); rhinitis-sleep (P = 0.024), non-nose/non-eye symptoms (P = 0.031), nasal problems (P = 0.015)]. In the open study Fel d 1 peptide treatment resulted in significant decreases in number of sneezes (P = 0.05), weight of nasal secretions (P = 0.04) and nasal blockage (P = 0.01) following allergen challenge. CONCLUSIONS: Multiple, short, overlapping Fel d 1 T-cell peptides have potential for inhibiting upper and lower airway outcome measurements in cat allergic patients. Larger, dose-ranging, studies are required before firm conclusions on clinical efficacy of peptide allergen therapy can be made.

Adult↗
PubMed2004

Intravenous anti-IL-5 monoclonal antibody reduces eosinophils and tenascin deposition in allergen-challenged human atopic skin.

Anti-IL-5 monoclonal antibody (mepolizumab) reduces baseline bronchial mucosal eosinophils and deposition of extracellular matrix proteins in the reticular basement membrane in mild asthma. Here we report the effect of anti-IL-5, in the same patients, on allergen-induced eosinophil accumulation, tenascin deposition (as a marker of repair and remodelling) and the magnitude of the late-phase allergic cutaneous reaction. Skin biopsies were performed in 24 atopic subjects at allergen- and diluent-injected sites before 6 and 48 h after, three infusions of a humanized, monoclonal antibody against IL-5 (mepolizumab) using a randomized double-blind, placebo-controlled design. Anti-IL-5 significantly inhibited eosinophil infiltration in 6 h and 48 h skin biopsies as well as the numbers of tenascin immunoreactive cells at 48 h. In contrast, anti-IL-5 had no significant effect on the size of the 6 or 48 h late-phase cutaneous allergic reaction. This study (a) suggests that eosinophils are unlikely to cause the redness, swelling, and induration characteristic of the peak (6 h) late-phase cutaneous allergic reaction and (b) shows that decreases in tenascin positive cells at 48 h correlates with reduction of eosinophils, so providing further evidence of involvement in remodelling processes associated with allergic inflammation.

Adolescent↗
PubMed2004

Interactions between eotaxin, histamine and mast cells in early microvascular events associated with eosinophil recruitment to the site of allergic skin reactions in humans.

BACKGROUND: The mechanism whereby allergen induces eotaxin expression at the site of allergic inflammation is incompletely understood. Structural cells, including endothelial cells, are a major source of eotaxin. OBJECTIVE: We have investigated, in vivo and in vitro, the relationship between mast cell activation and the expression of eotaxin (eotaxin 1) by endothelial cells. METHODS: The effects of intradermal allergen challenge and histamine injection on eotaxin mRNA and protein generation were studied in atopic subjects using immunofluorescence, immunohistochemistry and in situ hybridization. Histamine-induced expression of eotaxin mRNA and protein by endothelial cells was also measured, as was histamine-induced eosinophil adhesion to cultured endothelial cells. RESULTS: A rapid increase in degranulating cutaneous mast cells, together with a concomitant increase in eosinophils, was observed 60 min after allergen challenge. This was accompanied by the appearance of immunoreactive eotaxin that peaked at 1 h around blood vessels and at 3 h within the tissue. Intradermal histamine injection produced an increase in the number of eotaxin+ cells in the tissues, which was maximal at the 3-h time-point. In vitro, endothelial cells produced eotaxin mRNA and protein product in a dose- and time-dependent fashion following incubation with histamine, an effect that was blocked by levocetirizine. Pre-incubation of endothelial cells with histamine also induced a significant increase in eosinophil adherence, an effect that was inhibited with an anti-eotaxin blocking monoclonal antibody. CONCLUSION: The antigen-induced expression of eotaxin by endothelial cells and the adherence and subsequent migration of eosinophils from the microvasculature to the tissues are rapid events partially under the control of histamine released from degranulating mast cells.

Adult↗
PubMed2004

Cat allergen peptide immunotherapy reduces CD4(+) T cell responses to cat allergen but does not alter suppression by CD4(+) CD25(+) T cells: a double-blind placebo-controlled study.

BACKGROUND: We have previously described both modification of allergen immunotherapy using peptide fragments, and reduced regulation of allergen stimulated T cells by CD4(+) CD25(+) T cells from allergic donors when compared with nonallergic controls. It has been suggested that allergen immunotherapy induces regulatory T cell activity: we hypothesized that allergen peptide immunotherapy might increase suppressive activity of CD4(+) CD25(+) T cells. OBJECTIVE: To examine cat allergen-stimulated CD4 T cell responses and their suppression by CD4(+) CD25(+) T cells before and after cat allergen peptide immunotherapy in a double-blind placebo-controlled study. METHODS: Peripheral blood was obtained and stored before and after peptide immunotherapy or placebo treatment. CD4(+) and CD4(+) CD25(+) were then isolated by immunomagnetic beads and cultured with allergen in vitro. RESULTS: Comparing cells from blood taken before with that after peptide immunotherapy there was a significant reduction in both proliferation and IL-13 production by allergen-stimulated CD4+ T cells, whereas no change was seen after placebo. CD4(+) CD25(+) T cells suppressed both proliferation and IL-13 production by CD4(+) CD25(-) T cells before and after therapy but peptide therapy was not associated with any change in suppressive activity of these cells. CONCLUSION: Allergen peptide immunotherapy alters T cell response to allergen through mechanisms other than changes in CD4(+) CD25(+) T cell suppression.

Adolescent↗
PubMed2003

Cyclosporin A, apoptosis of BAL T-cells and expression of Bcl-2 in asthmatics.

The late asthmatic reaction is characterised by elevated numbers of interleukin-4/interleukin-5/CD4-positive T-helper cells type 2 in bronchoalveolar lavage fluid (BALF). Cyclosporin A (CsA) is known to inhibit T-cell proliferation, induce apoptosis of CD4-positive T-cells and downregulate cytokine gene expression. It was assessed whether CsA-induced inhibition of the late asthmatic reaction was associated with apoptosis of BALF T-lymphocytes and other cell types, as well as expression of the antiapoptotic protein B-cell leukaemia/lymphoma 2 gene product (Bcl-2). BALF cells were obtained from asthmatics at baseline and 24 h after allergen-inhalation challenge following prior administration of CsA (n=13) or placebo (n=11). The number of apoptotic CD3-positive T-lymphocytes increased in the CsA but not the placebo group. The numbers of Bcl-2-positive cells were significantly reduced in the CsA but not the placebo group. The majority of Bcl-2-positive cells were CD3-positive T-lymphocytes. The beneficial effect of cyclosporin A in asthma may be related to its inhibitory effect on the late asthmatic reaction via induction of T-cell apoptosis and decreased B-cell leukaemia/lymphoma 2 gene product levels.

Apoptosis↗
PubMed2002

Effect of T-cell peptides derived from Fel d 1 on allergic reactions and cytokine production in patients sensitive to cats: a randomised controlled trial.

BACKGROUND: Some patients with asthma who are allergic to cats and are injected intradermally with short, overlapping, T-cell peptides derived from Fel d 1 develop late asthmatic reactions to the peptides, which are associated with a reduction in late-phase skin reactions induced by whole allergens and bronchial hyporesponsiveness to the peptides on the second injection. We aimed to ascertain the effect of multiple injections on the magnitude of the early and late phase skin reactions to intact allergens. METHODS: After a 9-week run-in period, we randomly assigned patients with asthma and allergies to cats to receive either Fel d 1 peptides (90 microg in increasing divided doses) or placebo. The primary outcome was late-phase cutaneous reactions to whole cat dander. Outcomes were measured at baseline, 4-8 weeks, and 3-9 months. Analysis was by intention to treat. FINDINGS: 16 patients were randomly assigned to the peptides, and eight to placebo. All patients completed the course of injections. Four of the 16 patients on Fel d 1 peptides had initial late asthmatic reactions, but could be desensitised to the higher dose of peptide. Patients in the peptide group but not the placebo group had a significant reduction in the size of their late reaction to whole cat dander between baseline and both follow-ups, but the difference between groups was not significant (first follow-up, difference -422.8 mm(2) [95% CI -1115.0 to 269.4], p=0.43; second follow-up -1180.8 mm(2) [-2216.8 to -144.8], p=0.058). The size of the late reaction to Fel d 1 significantly differed between treatment groups at both follow-ups. At second follow-up, the size of the early reaction to Fel D 1, but not to whole cat dander was significantly reduced in those on peptides compared with those on placebo. The concentration of interferon gamma and of interleukin 4 and 13, and the amount of proliferation, significantly decreased between baseline and second follow-up, and the concentration of interleukin 10 was significantly higher in patients on peptides, however, none of these values differed significantly between groups. Patients on peptides had a significantly greater decrease in the concentration of interferon gamma and interleukin 13, and in the amount of proliferation between baseline and first follow-up than did those on placebo. INTERPRETATION: Several, short, overlapping Fel d 1 T-cell peptides have potential in treatment of cat allergy.

Adult↗
PubMed2002

Elevated expression of interleukin-9 mRNA in the bronchial mucosa of atopic asthmatics and allergen-induced cutaneous late-phase reaction: relationships to eosinophils, mast cells and T lymphocytes.

BACKGROUND: Interleukin-9 is a T cell-derived Th2-type cytokine that has been linked to airway hyper-responsiveness, mucus hypersecretion and mast cell infiltration in animal models. We recently demonstrated the potential for IL-9 to act in human eosinophil development and survival. OBJECTIVES: The aims of this study were: (i) to compare IL-9 mRNA expression in bronchial biopsies between atopic asthmatics and normal controls, (ii) to investigate kinetic expression of IL-9 mRNA in skin biopsies after allergen challenge; and (iii) to relate IL-9 expression to infiltration of eosinophils, mast cell and T lymphocytes in local tissue. METHODS: Bronchial biopsies were obtained from atopic asthmatics (n = 12) and normal non-asthmatics (n = 12) at baseline. Skin biopsies were obtained from atopic subjects (n = 11) at 1, 3, 6, 24, 48 and 72 h after allergen challenge. Diluent challenge sites at 24 h were used as controls. IL-9 mRNA was identified using the technique of in situ hybridization. The numbers of eosinophils, mast cells and T cells were evaluated by immunohistochemistry. RESULTS: The numbers of IL-9 mRNA(+) cells present in the bronchial mucosa were significantly greater in atopic asthmatics than those in normal controls (P = 0.003). The numbers of eosinophils, but not mast cells, were also significantly higher in asthmatics (P < 0.005). The numbers of IL-9 mRNA(+) cells present in the airway of asthmatics significantly correlated with the numbers of eosinophils (r = 0.623, P = 0.03), but not mast cells or T cells. Compared with diluent challenge, the numbers of IL-9 mRNA(+) cells were significantly elevated at all allergen-challenged sites in the skin, with maximal signals at 48 h (P < 0.005). At 72 h, the numbers of IL-9 mRNA(+) cells significantly correlated with the numbers of eosinophils (r = 0.707, P = 0.015). CONCLUSION: Elevated expression of IL-9 in allergic inflammation may contribute to local eosinophil infiltration and survival in asthma and other allergic atopic diseases.

Adult↗
PubMed2001

Allergen-derived T cell peptide-induced late asthmatic reactions precede the induction of antigen-specific hyporesponsiveness in atopic allergic asthmatic subjects.

Allergen-derived peptides can induce T cell tolerance in naive and Ag-primed mice. This is preceded by transient T cell activation. In humans, intradermal administration of short allergen-derived T cell peptide epitopes provokes IgE-independent isolated late asthmatic reactions (LARs) in sensitized subjects. In this study, we determine whether, as in mouse models, such peptides produce hyporesponsiveness to rechallenge with peptides, or whole allergen, either clinically or in terms of in vitro T cell responses. We found that a second injection of cat allergen (Fel d 1)-derived T cell peptides was associated with a marked reduction, or absence, of the LAR, and that up to 40 wk was required for return to baseline values. The cutaneous late-phase reaction to whole cat dander was also inhibited, even in subjects who did not experience an initial LAR. These observations were associated with a significant decrease in peptide- and whole allergen-induced proliferation of PBMCs and the production of IL-4, IL-13, and IFN-gamma in cultures. Thus, allergen-derived peptides induce tolerance to subsequent peptide injection in the target organ (the lung), reduce late-phase cutaneous responsiveness to whole allergen, and alter in vitro T cell reactivity.

Allergens↗
PubMed2001

Interleukin-10 levels increase in cutaneous biopsies of patients undergoing wasp venom immunotherapy.

We have studied the influence of wasp venom immunotherapy (VIT) on cellular recruitment and cytokine mRNA expression during allergen-induced cutaneous late-phase responses (LPR). Nine subjects with a history of wasp sting anaphylaxis, and specific IgE in their sera underwent wasp VIT. Skin biopsies were taken 24 h after intradermal diluent and allergen before and after 3 months VIT. Pre-immunotherapy, there were significant allergen-induced increases in EG2(+) eosinophils, elastase(+) neutrophils, CD68(+) macrophages and IL-10 protein(+) cells, and increased expression of mRNA for IL-4, IL-13, IFN-gamma, IL-12, IL-10, TGF-beta, RANTES and eotaxin. When these allergen-induced changes in cytokine mRNA and cellular profiles were compared with those obtained after 3 months VIT there was a significant reduction in IL-4 mRNA (p=0.012) and increase in IL-10 protein(+) cells (p=0.004) with a trend to an increase in IL-10 mRNA (p=0.054). There were also significant reductions in eosinophils (p<0.004) and the size of the cutaneous LPR (p<0.01) but no change in mRNA to IFN-gamma, IL-13 or IL-12. Therefore, VIT is associated with a significant increase in cells positive for IL-10 protein but not IL-12 or IFN-gamma. These results suggest that induction of IL-10 may be important in VIT and occur independently of the switch to a Th1 phenotype. IL-10 generation may down-regulate IL-4 expression and eosinophil recruitment.

Adult↗
PubMed2001

Macrophage inflammatory protein-1alpha and C-C chemokine receptor-1 in allergen-induced skin late-phase reactions: relationship to macrophages, neutrophils, basophils, eosinophils and T lymphocytes.

BACKGROUND: Macrophage inflammatory protein (MIP)-1alpha binds to C-C chemokine receptor (CCR)-1 with high affinity. CCR-1 is expressed on neutrophils, eosinophils, monocytes, T lymphocytes and basophils; cells characteristic of atopic allergic inflammation. In vitro, MIP-1alpha is chemotactic for monocytes, T cells and basophils and is also a potent histamine-releasing factor for basophils and mast cells. Although increased levels of MIP-1alpha were shown in atopic allergic disorders, the kinetics of expression of these CC chemokines in vivo is largely unknown. OBJECTIVE: To investigate the kinetics of expression of MIP-1alpha and receptor CCR-1 and the relationships between the expression and infiltration of inflammatory cells in allergen-induced cutaneous late-phase reactions in atopic subjects. METHODS: Cryostat sections, obtained from skin biopsies from 10 human atopic subjects at 6, 24, 48, 72 h and 7 days after allergen challenge, were processed for immunohistochemistry and in situ hybridization using 35S-labelled riboprobes. RESULTS: The peak expression of allergen-induced mRNA for MIP-1alpha and CCR-1 was 6 h. This was maintained at 24 h, and gradually returned to base line at 7 days. At 6 h, the number of cells expressing MIP-1alpha mRNA significantly correlated with elastase+ neutrophils and BB-1+ basophils. At 24 h, the MIP-1alpha mRNA+ cells significantly correlated with CD68+ macrophages. There were significant inverse correlations between the numbers of MIP-1alpha mRNA cells and the numbers of Tryptase+ mast cells at 6 and 24 h after allergen challenge. CONCLUSION: Allergen-induced cutaneous late-phase reactions in humans were associated with increased expression of MIP-1alpha and CCR-1. This may be relevant to the infiltration of neutrophils, eosinophils, basophils and macrophages.

Basophils↗
PubMed2001

Local expression of epsilon germline gene transcripts and RNA for the epsilon heavy chain of IgE in the bronchial mucosa in atopic and nonatopic asthma.

BACKGROUND: The demonstration of epsilon germline gene (Cepsilon) transcripts and mature mRNA for the epsilon heavy chain gene (Iepsilon) in the nasal mucosa suggested that IgE synthesis may occur in allergic rhinitis. OBJECTIVE: In view of our previous demonstration of increases in IL-4 mRNA(+) cells in asthmatic subjects, we assessed whether local IgE synthesis may also be a feature of bronchial asthma. METHODS: Fiberoptic bronchoscopic mucosa biopsy specimens were obtained from 9 atopic asthmatic subjects and 10 nonatopic normal (intrinsic) control subjects. To control for atopy, we also studied 9 nonatopic asthmatic subjects and 10 atopic nonasthmatic control subjects. Tissue was processed for immunohistochemistry for B cells (CD20) and in situ hybridization for Iepsilon and Cepsilon RNA(+) cells and IL-4 mRNA(+) cells. RESULTS: B-cell numbers in the bronchial mucosa were similar for asthmatic subjects compared with control subjects, whereas significantly higher numbers of Iepsilon RNA(+) (P =.02 and P =.04, respectively), Cepsilon RNA(+) (P =.01 and P =.03, respectively), and IL-4 mRNA(+) (P =.001 and P =.001, respectively) cells were observed in atopic asthmatic subjects and nonatopic asthmatic subjects, respectively, but not in atopic control subjects compared with nonatopic control subjects. In asthmatic subjects there were significant correlations between Iepsilon RNA(+) cells (r = 0.54, P =.02) and Cepsilon RNA(+) cells (r = 0.48, P =.05) when compared with the number of IL-4 mRNA(+) cells. CONCLUSION: Increases in Iepsilon and Cepsilon RNA(+) cells, but not B-cell numbers, in the bronchial mucosa provide evidence for local IgE synthesis in both atopic and nonatopic asthma. These changes appear to relate to asthma rather than atopy per se and, at least in part, may be under the regulation of IL-4.

Adult↗
PubMed2001

Late asthmatic reactions provoked by intradermal injection of T-cell peptide epitopes are not associated with bronchial mucosal infiltration of eosinophils or T(H)2-type cells or with elevated concentrations of histamine or eicosanoids in bronchoalveolar fluid.

BACKGROUND: Isolated late asthmatic reactions can be provoked by intradermal challenge of allergen-derived T-cell peptide epitopes. OBJECTIVE: The purpose of this study was to determine whether the isolated LAR is associated with the local accumulation of inflammatory cells, the expression of T(H)2 cytokines, and the production of pharmacologic mediators. METHODS: A randomized, placebo-controlled, crossover study design was used. The investigation involved bronchial and skin biopsies and bronchoalveolar lavage (BAL) fluids from 8 cat-allergic subjects who developed significant late asthmatic reactions 6 hours after intradermal injection of Fel d 1 chain 1-derived peptides (FC1Ps). RESULTS: Immunostaining of bronchial biopsy specimens showed no changes in the numbers of eosinophils, neutrophils, basophils, mast cells, CD3(+), CD4(+) or CD8(+) T cells, CD25(+) cells or macrophages, or cells mRNA(+) for IL-4, IL-5, or IL-13 when the FC1P day was compared with the diluent control day. There were also no significant differences in eosinophil numbers, either in BAL fluids or in peripheral blood after FC1P challenge. Furthermore, there were no significant alterations in the concentrations of histamine, histamine-releasing factors, or eicosanoids (LTC(4)/D(4)/E(4), PGD(2), PGE(2), TXB(2), PGF(2alpha)) in BAL fluids. FC1Ps induced a significant (P <.05) elevation in CD8(+) cells in the skin and an unexpected decrease in IL-5 in BAL fluids (P =.043). CONCLUSION: Part of the asthma process might involve T cell-dependent airway narrowing with no requirement for IgE, mast cells, or infiltrating inflammatory cells.

Adult↗