Anita E Blake

University of Sydney, Sydney, New South Wales, Australia

Are you Anita E Blake?

Claim your profile

Publications (6)33.4 Total impact

  • J Chhabra · Y-Z Li · H Alkhouri · A E Blake · Q Ge · C L Armour · J M Hughes ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Degranulating mast cells are increased in the airway smooth muscle (ASM) of asthmatics, where they may influence ASM function. The aim of the present study was to determine whether histamine and tryptase modulate ASM cell granulocyte-macrophage colony-stimulating factor (GM-CSF) and RANTES (regulated on activation, normal T-cell expressed and secreted) release and also to examine which receptors are involved in this release. Confluent, quiescent ASM cells from asthmatic and nonasthmatic donors were treated with histamine (1 microM-100 microM) with and without histamine receptor antagonist pre-treatment, or the protease-activated receptor (PAR)-2 agonists tryptase (0.5-5 nM) and SLIGKV (100 and 400 microM). The cells were then stimulated with interleukin (IL)-1beta and/or tumour necrosis factor (TNF)-alpha (10 ng.mL(-1)) or left unstimulated for 24 h. Release of GM-CSF and RANTES was determined by ELISA and prostaglandin (PG)E(2) measured by enzyme immunoassay. Neither histamine nor tryptase induced ASM GM-CSF or RANTES secretion. However, histamine increased IL-1beta-induced GM-CSF release and markedly reduced TNF-alpha-induced RANTES release by both asthmatic and nonasthmatic cells to a similar extent, but did not modulate PGE(2) release. All changes involved activation of the histamine H1 receptor as they were partially or fully blocked by chlorpheniramine, but not ranitidine. Tryptase, via its proteolytic activity, also potentiated GM-CSF, but not RANTES, release from asthmatic and nonasthmatic ASM cells induced by both cytokines. PAR-2 involvement in the tryptase potentiation was unlikely because SLIGKV had no effect. In conclusion, mast cells, through histamine and tryptase, may locally modulate airway smooth muscle-induced inflammation in asthma.
    European Respiratory Journal 06/2007; 29(5):861-70. DOI:10.1183/09031936.00106306 · 7.64 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Severe, persistent asthma is characterized by airway smooth muscle hyperplasia, inflammatory cell infiltration into the smooth muscle, and increased expression of many cytokines, including IL-4, IL-13, IL-1beta, and TNF-alpha. These cytokines have the potential to alter the expression of surface receptors such as CD40 and OX40 ligand on the airway smooth muscle cell. To examine whether cytokines alter expression of CD40 and OX40 ligand on airway smooth muscle cells and identify any differences in response between asthmatic and nonasthmatic airway smooth muscle cells. We used flow cytometry and immunohistochemistry to detect CD40 and OX40 ligand on airway smooth muscle cells cultured in the presence of TNF-alpha, IL-1beta, IL-4, or IL-13. Prostaglandin E 2 levels were assessed by ELISA. TNF-alpha increased expression of both CD40 and OX40 ligand on both asthmatic and nonasthmatic airway smooth muscle cells. The level of expression was significantly greater on the asthmatic cells. IL-1beta alone had no effect, but it attenuated the TNF-induced expression of both CD40 and OX40 ligand. The mechanism of inhibition was COX-dependent for CD40 and was COX-independent but cyclic AMP-dependent for OX40 ligand. IL-4 and IL-13 had no effect. Our study has demonstrated that TNF-alpha and IL-1beta have the potential to modulate differentially the interactions between cells present in the inflamed airways of a patient with asthma and therefore to contribute to the regulation of airway inflammation and remodeling.
    Journal of Allergy and Clinical Immunology 03/2005; 115(2):302-8. DOI:10.1016/j.jaci.2004.11.004 · 11.48 Impact Factor
  • D J Lalor · B Truong · S Henness · AE Blake · Q Ge · AJ Ammit · C L Armour · J M Hughes ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Inflammation and vascular leakage are prevalent in asthma. This study aimed to elucidate the mechanisms involved in serum potentiation of cytokine-induced granulocyte macrophage colony stimulating factor (GM-CSF) production by human airway smooth muscle cells and to identify possible factors responsible. Serum-deprived cells at low density were stimulated with TNF-alpha and IL-1beta for 24 h. Human AB serum (10%), inhibitors of RNA and protein synthesis or specific signaling molecules, or known smooth muscle mitogens were then added for 24 h. Culture supernatants were analyzed for GM-CSF levels, and cells were harvested to assess viability, cell cycle progression, GM-CSF-specific mRNA content, and p38 phosphorylation. Serum potentiated GM-CSF release when added before, together with (maximal), or after the cytokines. The potentiation involved both new GM-CSF-specific mRNA production and protein synthesis. The mitogens IGF, PDGF, and thrombin all potentiated GM-CSF release, and neutralizing antibodies for EGF, IGF, and PDGF reduced the serum potentiation. Inhibitor studies ruled as unlikely the involvement of p70(S6kinase) and the MAPK p42/p44, two signaling pathways implicated in proliferation, and the involvement of the MAPK JNK, while establishing roles for p38 MAPK and NF-kappaB in the potentiation of GM-CSF release. Detection of significant p38 phosphorylation in response to serum stimulation, through Western blotting, further demonstrated the involvement of p38. These studies have provided evidence to support p38 being targeted to interrupt the cycle of inflammation, vascular leakage and cytokine production in asthma.
    AJP Lung Cellular and Molecular Physiology 12/2004; 287(5):L1007-16. DOI:10.1152/ajplung.00126.2004 · 4.08 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Successful control of sexually transmitted diseases (STDs) through vaccination will require the development of vaccine strategies that target protective immunity to both the female and male reproductive tracts (MRT). In the male, the immune privileged nature of the male reproductive tract provides a barrier to entry of serum immunoglobulins into the male reproductive ducts, thereby preventing the induction of protective immunity using conventional injectable vaccination techniques. In this study we investigated the potential of intranasal (IN) immunization to elicit anti-chlamydial immunity in BALB/c male mice. Intranasal immunization with Chlamydia muridarum major outer membrane protein (MOMP) admixed with cholera toxin (CT) resulted in high levels of MOMP-specific IgA in prostatic fluids (PF) and MOMP-specific IgA-secreting cells in the prostate. Prostatic fluid IgA inhibited in vitro infection of McCoy cells with C. muridarum. Using RT-PCR we also show that mRNA for the polymeric immunoglobulin receptor (PIgR), which transports IgA across mucosal epithelia, is expressed only in the prostate but not in other regions of the male reproductive ducts upstream of the prostate. These data suggest that using intranasal immunization to target IgA to the prostate may protect males against STDs while at the same time maintaining the state of immune privilege within the MRT.
    Vaccine 11/2004; 22(31-32):4306-15. DOI:10.1016/j.vaccine.2004.04.021 · 3.62 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The extension of airway smooth muscle cell (ASMC) functions, from just contractile, to synthetic and/or proliferative states, is an important component of airway remodelling and inflammation in asthma. Whereas all these functions have been demonstrated in ASM, currently, it is not known whether ASMC can be differentiated on the basis of their proliferative and synthetic functions. We used flow-cytometric techniques to determine, first, whether human ASMC are phenotypically heterogenous with regard to their secretory function, and second, the proliferative status of secretory cells. ASMC were induced to synthesize GM-CSF by stimulation with IL-1beta and TNF-alpha followed by 10% human serum. Flow-cytometric detection of intracellular GM-CSF revealed that only a proportion of cells in culture (approximately 20-60%) synthesize GM-CSF. To determine the proliferative status of GM-CSF producing cells, ASMC were pretreated with 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE), a fluorescein based dye used to track cell division, prior to cytokine/serum stimulation. Simultaneous analysis of intracellular GM-CSF and CFSE revealed that GM-CSF producing cells were present in both the divided and undivided ASMC populations. Thus, cytokine production and proliferation occurred in overlapping ASMC populations and prior progression through the cell cycle was not essential for ASMC cytokine production.
    Immunology and Cell Biology 11/2004; 82(5):471-8. DOI:10.1111/j.0818-9641.2004.01275.x · 4.15 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Successful immunocontraception using sperm antigens is dependent on achieving sufficient sperm-specific antibody in the reproductive ducts to prevent fertilization. The blood: luminal barrier of the male and female reproductive ducts must be overcome for this to occur. We have, therefore, investigated the relative titers of antigen-specific immunoglobulin G (IgG) in luminal fluids collected from male and female rabbit reproductive ducts following immunization with recombinant rabbit PH-20 (rPH-20). Male and female rabbits were immunized subcutaneously with rPH-20 in Freund's adjuvant. Reproductive tract fluids and plasma were collected and assayed for specific IgG by enzyme-linked immunoabsorbent assay (ELISA). Plasma anti-rPH-20 antibodies were tested for their ability to inhibit in vitro fertilization. Plasma rPH-20-specific IgG titers of > 21 x 106 were induced in bucks. Antibody levels in the rete testis and cauda epididymidis fluids were only 0.026 and 0.168% of plasma levels, respectively. Plasma IgG titers were > 30 x 10(6) in does, but antibody levels in free flow vaginal fluid, free flow uterine fluid and free flow oviduct fluid were only 0.016, 0.078 and 0.072% of plasma levels, respectively. Induction of ovulation by administration of human chorionic gonadotrophin (hCG) significantly increased rPH-20-specific IgG only in free flow vaginal fluids. Plasma antibody from immunized rabbits inhibited in vitro fertilization but conception rates following mating of rPH-20 immunized male to untreated female rabbits were not affected. The IgG antibody entry into the reproductive ducts of both male and female rabbits is restricted to less than 0.2% of levels induced in plasma following subcutaneous immunization. This finding raises doubts about the suitability of rPH-20 to induce immunocontraception in rabbits using strategies optimized for induction of a serum antibody response. Whether mucosal immunization strategies can achieve this remains to be tested.
    American journal of reproductive immunology (New York, N.Y.: 1989) 03/2002; 47(3):174-82. DOI:10.1034/j.1600-0897.2002.1o056.x · 2.44 Impact Factor