Anja P Bieneman

Johns Hopkins Medicine, Baltimore, MD, United States

Are you Anja P Bieneman?

Claim your profile

Publications (31)119.09 Total impact

  • The Journal of allergy and clinical immunology 10/2013; · 12.05 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Food allergy (FA) and eosinophilic oesophagitis (EE) are increasingly common clinical problems. Dendritic cells (DCs) are key regulators of the sensitization and effector phases of allergic immune responses, but their role in these diseases is largely unknown. To evaluate for alterations in the phenotype and function of DCs in children with IgE-mediated milk allergy or EE compared with their non-affected siblings. Plasmacytoid DCs (pDCs) and myeloid DCs (mDCs) were prepared from peripheral blood of children with milk allergy (FA), EE, and non-affected siblings (CON). Purified pDCs and mDCs were cultured alone or with autologous CD4(+) lymphocytes. Cytokine levels in plasma, or culture supernatants following stimulation, were measured using multiplex array immunoassay. Cell-surface molecule expression was determined by flow cytometry. DCs from FA subjects produced greater levels of pro-inflammatory cytokines (IL-6, TNF-α), granulocyte macrophage-colony forming factor, and mDC-derived IL-10 compared with controls following allergen exposure. T(H) 2 but not T(H) 1 cytokines were spontaneously produced in DC-CD4(+) T cell co-cultures from children with FA and were not significantly increased after stimulation with milk extract, suggesting an ongoing activation in vivo. This hypothesis was further supported by evidence for elevated IL-5 and IL-13 protein in the plasma of children with both FA and EE. The only significant DC phenotypic differences were: (1) reduced levels of CD80 in EE subjects and (2) FcɛRI expression that correlated with serum IgE levels in both groups of subjects. This study suggests that DCs from children with FA and EE produce more pro-inflammatory cytokines, and that their CD4(+) T cells are spontaneously activated to produce T(H) 2 cytokines in the presence of FcɛRI-bearing DCs.
    Clinical & Experimental Allergy 01/2011; 41(1):61-71. · 4.79 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2011; 127(2).
  • [show abstract] [hide abstract]
    ABSTRACT: Dendritic cells (DCs) and other professional antigen-presenting cells express a variant of the high-affinity IgE receptor known as alphagamma(2), which, on the basis of in vitro findings, has long been implicated to function in facilitating allergen uptake and presentation to T(H) cells. To use omalizumab as an in vivo tool to neutralize IgE binding to circulating dendritic cells and to assess whether this results in altered DC-dependent T-cell responsiveness to allergen ex vivo. Subjects with cat allergy were enrolled in a 3.5-month, double blind, randomized (3.5:1), placebo-controlled trial of omalizumab using standard dosing for allergic asthma. Blood plasmacytoid and myeloid DCs were assessed at baseline and posttreatment for expression of surface IgE, FcepsilonRIalpha, and induction of CD4(+)T-cell proliferation and cytokine responses to cat allergen. IgE expression on plasmacytoid and myeloid DCs from omalizumab-treated subjects (n = 12) decreased by > or =95% posttreatment (P = .0005), whereas FcepsilonRIalpha expression decreased by 66% and 48%, respectively (P = .0005). Cat allergen-induced proliferation in DC/T-cell cocultures observed at baseline was suppressed approximately 20% to 40% postomalizumab treatment (P = .001). Multiplexing for cytokines in plasmacytoid DC/T-cell cocultures also showed decreases in IL-5, IL-13, and IL-10 (P < .05), whereas IL-2 and IFN-gamma were unaltered or slightly increased. These changes were not evident in placebo-control subjects (n = 4). IgE likely facilitates allergen presentation by dendritic cells in vivo and is also important in regulating DC-dependent T-cell cytokines during effector phases of allergic disease.
    The Journal of allergy and clinical immunology 04/2010; 125(4):896-901.e6. · 12.05 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Allergic inflammatory processes may have the capacity to propagate systemically through the actions of circulating leucocytes. Consequently, basophils from allergic individuals are often 'primed', as evidenced by their hyperresponsiveness in vitro. IFN-alpha secreted predominantly by plasmacytoid dendritic cells (pDCs), suppresses basophil priming for IL-13 production in vitro. This study sought in vivo correlates arising during experimental allergen challenge that support an 'axis-interplay' between basophils and pDCs. Using segmental allergen challenge (SAC) in the lung, the immune responses of both cell types from the blood were investigated in volunteers (n=10) before and 24 h after allergen exposure. These responses were then correlated with inflammatory parameters measured in bronchoalveolar lavage fluids (BALF). In the blood, SAC significantly augmented IL-13 secretion by basophils induced by IL-3 (P=0.009), yet reduced IFN-alpha secreted by pDCs stimulated with CpG (P=0.018). Both parameters were negatively correlated (P=0.0015), at least among those subjects that secreted the latter. Circulating basophil IL-13 responses further correlated with post-SAC bronchoalveolar lavage (BAL) parameters including IL-13 protein (P=0.04), basophil (P=0.051), eosinophil (P=0.0018), and total cell counts (P<0.003). Basophil and IL-13 levels in BAL correlated likewise (P=0.0002). These results support a mechanism of immune regulation whereby an allergen reduces innate immune responses and IFN-alpha production by pDCs, resulting in an enhanced inflammation and basophil cytokine production at sites of allergen exposure.
    Clinical & Experimental Allergy 02/2010; 40(5):745-54. · 4.79 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2010; 125(2).
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: We recently reported that human blood dendritic cells from allergic subjects have impaired IFN-alpha production following toll-like receptor 9 (TLR9)-dependent innate immune stimulation. It is not known how subcutaneous allergen immunotherapy (SCIT) affects dendritic cell immune responses. The aim of this study is to determine how SCIT affects human dendritic cell function. Peripheral blood mononuclear cell (PBMC) and plasmacytoid dendritic cells (pDCs) were isolated from the blood of seven dust mite allergic subjects at baseline and upon reaching a standard SCIT maintenance dose that included dust mite and other aeroallergens. Cells were stimulated with various adaptive and innate immune receptor stimuli, or media alone for 20 h with secreted cytokine levels determined by ELISA. A portion of the cells were used to measure intracellular signalling proteins by flow cytometry. Humoral immune responses were measured from plasma. SCIT resulted in a threefold increase in PBMC production of IFN-alpha in response to CpG at 100 nM (P=0.015) and at 500 nM (P=0.015), n=7. The predominant cell type known to produce IFN-alpha in response to CpG (CpG ODN-2216) and other TLR9 agonists is the pDC. As expected, a robust innate immune response from isolated pDCs was re-established among allergic subjects undergoing SCIT resulting in a fivefold increase in IFN-alpha production in response to CpG at 500 nM (P=0.046), n=7. In contrast, IL-6 production was unaffected by SCIT (P=0.468). Consistent with published reports, IgG4 blocking antibody increased 10-fold with SCIT (P=0.031), n=7. There was no significant increase in the frequency of pDCs or the expression of TLR9 that would account for the rise in IFN-alpha production. Allergen immunotherapy increases dendritic cell TLR9-mediated innate immune function, which has previously been shown to be impaired at baseline in allergic subjects.
    Clinical & Experimental Allergy 01/2010; 40(1):94-102. · 4.79 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2010; 125(2).
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Although IL-3 is commonly recognized for its growth factor-like activity, in vitro studies have long demonstrated a unique capacity for this cytokine to also augment the proinflammatory properties and phenotype of human basophils. In particular, basophils secrete mediators that are hallmarks in allergic disease, including vasoactive amines (e.g., histamine), lipid metabolites (e.g., leukotriene C(4)), and cytokines (e.g., IL-4/IL-13), which are all markedly enhanced with IL-3 pretreatment. This priming phenomenon is observed in response to both IgE-dependent and IgE-independent stimulation. Additionally, IL-3 directly activates basophils for IL-13 secretion and enhanced CD69 expression, two markers that are elevated in allergic subjects. Lymphocytes are commonly thought to be the source of the IL-3 that primes for these basophil responses. However, we demonstrate herein for the first time that basophils themselves rapidly produce IL-3 (within 4 h) in response to IgE-dependent activation. More importantly, our findings definitively show that basophils rapidly bind and utilize the IL-3 they produce, as evidenced by functional and phenotypic activity that is inhibited in the presence of neutralizing anti-IL-3 receptor (CD123) Abs. We predict that autocrine IL-3 activity resulting from low-level IgE/FcepsilonRI cross-linking by specific allergen represents an important mechanism behind the hyperreactive nature of basophils that has long been observed in allergic disease.
    The Journal of Immunology 03/2009; 182(4):2432-8. · 5.52 Impact Factor
  • J. Tversky, A. Bieneman, J. Schroeder
    Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2009; 123(2).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2009; 123(2).
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Immature human blood monocytoid dendritic cells (mDCs) express high-affinity receptors for IgE (Fc epsilon RI), yet their exact function and regulation remain poorly understood. We sought to characterize Fc epsilon RI-dependent cytokine responses and their regulation in circulating human blood mDCs. Fc epsilon RI-dependent cytokine responses of circulating mDCs were studied by using anti-Fc epsilon RI alpha stimulation. Plasmacytoid dendritic cell (pDC) cross-regulation through Toll-like receptor 9 on these responses was investigated by examining the effects of exogenous IFN-alpha pretreatment and by coculturing pDCs and mDCs stimulated with CpG. Culture supernatants were analyzed by means of ELISA to determine cytokine levels. Cell markers were determined by means of flow cytometry. mDCs express marked levels of Fc epsilon RI (net mean fluorescence intensity, 196 +/- 49; n = 4). After Fc epsilon RI-dependent activation in mDCs, TNF-alpha (2189 +/- 864 pg/10(6) mDCs, n = 3) levels were upregulated within 4 hours, whereas IL-10 (112 +/- 47 pg/10(6) mDCs, n = 3) levels were detectable only after 24 hours of incubation. After adding IL-10-neutralizing antibody, TNF-alpha Fc epsilon RI-dependent responses were significantly augmented (3903 +/- 197 pg/10(6) mDCs, P < .01, n = 3). Conversely, recombinant IL-10 dose-dependently inhibited Fc epsilon RI-mediated TNF-alpha responses up to 86% +/- 3% (n = 3, P < .001). Pretreatment of mDCs with IFN-alpha (100 U/mL) enhanced Fc epsilon RI-dependent secretion of IL-10 by 3.2-fold (183 +/- 11 pg/10(6) mDCs, n = 4) compared with that seen in untreated cells (57 +/- 33 pg/10(6) mDCs, P < .001, n = 4). In pDC/mDC cocultures pretreated with CpG, Fc epsilon RI-dependent IL-10 secretion by mDCs was similarly augmented by 3-fold. Autocrine secretion of IL-10, a critical autoregulator of Fc epsilon RI-dependent proinflammatory responses in mDCs, is cross-regulated by IFN-alpha, a major product of Toll-like receptor 9 responses in pDCs that normally promotes T(H)1 immunity.
    The Journal of allergy and clinical immunology 10/2008; 123(1):217-23. · 12.05 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: Previously, we demonstrated a negative correlation between histamine release to histamine-releasing factor/translationally controlled tumor protein (HRF/TCTP) and protein levels of SHIP-1 in human basophils. The present study was conducted to investigate whether suppressing SHIP-1 using small interfering (si)RNA technology would alter the releasability of culture-derived mast cells and basophils, as determined by HRF/TCTP histamine release. Frozen CD34+ cells were obtained from the Fred Hutchinson Cancer Research Center (Seattle, WA, USA). Cells were grown in StemPro-34 medium containing cytokines: mast cells with IL-6 and stem cell factor (100 ng/ml each) for 6-8 weeks and basophils with IL-3 (6.7 ng/ml) for 2-3 weeks. siRNA transfections were performed during Week 6 for mast cells and Week 2 for basophils with siRNA for SHIP-1 or a negative control siRNA. Changes in SHIP-1 expression were determined by Western blot. The functional knockdown was measured by HRF/TCTP-induced histamine release. siRNA knockdown of SHIP-1 in mast cells ranged from 31% to 82%, mean 65 +/- 12%, compared with control (n=4). Histamine release to HRF/TCTP was increased only slightly in two experiments. SHIP-1 knockdown in basophils ranged from 34% to 69%, mean 51.8 +/- 7% (n=4). Histamine release to HRF/TCTP in these basophils was dependent on the amount of SHIP knockdown. Mast cells and basophils derived from CD34+ precursor cells represent suitable models for transfection studies. Reducing SHIP-1 protein in cultured mast cells and in cultured basophils increases releasability of the cells.
    Journal of Leukocyte Biology 08/2008; 84(4):1151-8. · 4.57 Impact Factor
  • Source
    [show abstract] [hide abstract]
    ABSTRACT: High-affinity IgE receptor (Fc epsilon RI) expression on blood dendritic cells reportedly correlates with serum IgE levels. Our studies demonstrate that plasmacytoid dendritic cells (pDCs) secrete pro-inflammatory cytokines (IL-6, TNF-alpha) following Fc epsilon RI stimulation - a mode of activation that simultaneously reduces expression of Toll-like receptor 9 (TLR9). Whether or not TLR9 and/or Fc epsilon RI levels and their function on dendritic cells relate to allergic status is unknown. The aim of this study is to compare the innate (TLR9-mediated) immune response of human pDCs to TLR9 and Fc epsilon RI alpha receptor expression in allergic and non-allergic subjects. Basophil-depleted mononuclear cell fractions containing pDCs were prepared from peripheral blood of allergic and non-allergic subjects. Intracellular TLR9 and surface Fc epsilon RI alpha expression in blood dendritic cell antigen-2-positive cells were determined by flow cytometry. Activating anti-IgE antibody, anti-Fc epsilon RI alpha antibody, and TLR9 agonist were used to stimulate cell suspensions, with cytokine levels determined by ELISA. No difference in the frequency of pDCs was detected among allergic (n=9) vs. non-allergic (n=11) subjects (P=0.261). While there was also no difference in the baseline expression of TLR9, pDCs from allergic subjects produced sixfold less IFN-alpha when stimulated with CpG (P=0.002). Conversely, there was higher Fc epsilon RI alpha expression (P=0.01) on the pDCs of allergic subjects. Impaired TLR9-dependent immune responses in human pDCs are associated with allergic status and inversely correlated with Fc epsilon RI alpha expression. This impaired innate immune response among dendritic cells of allergic subjects may lead to more targeted therapeutic approaches and could provide a better understanding of the mechanisms underlying conventional and CpG-based immunotherapy.
    Clinical & Experimental Allergy 06/2008; 38(5):781-8. · 4.79 Impact Factor
  • [show abstract] [hide abstract]
    ABSTRACT: Functional significance for the alphagamma(2) variant of the high-affinity IgE receptor (FcepsilonRI) reportedly expressed on human dendritic cell subtypes remains poorly understood. Studies show that immature plasmacytoid dendritic cells (pDCs) secrete large quantities of TNF-alpha and IL-6 when directly stimulated with anti-IgE antibody. This mode of activation, however, reduces Toll-like receptor 9 (TLR9) expression in pDCs and their ability to mount an IFN-alpha response when subsequently activated with oligodeoxynucleotide containing CpG. To investigate the mechanisms underlying this IgE-dependent suppression of TLR9 and innate immune responsiveness in pDCs by focusing on autocrine cytokine responses. pDCs were isolated from blood by using blood dendritic cell antigen 4 selection. Cytokine responses to anti-IgE antibody-dependent and/or CpG-dependent stimulation were measured by using ELISA. TLR9 expression was determined by using quantitative RT-PCR and Western blotting. The time required for downregulating TLR9 expression in pDCs after anti-IgE stimulation correlated with the induction and duration of TNF-alpha secreted by these cells. Pretreatment of pDCs with recombinant TNF-alpha (but not IL-6 or IL-10) markedly suppressed TLR9 expression. Functional response to CpG (ie, IFN-alpha induction) was also inhibited with TNF-alpha pretreatment (inhibitory concentration(50) = approximately 200 pg/mL). Finally, an antibody that neutralizes TNF-alpha activity completely restored TLR9 expression during anti-IgE stimulation and significantly improved IFN-alpha secretion on subsequent activation with CpG. Autocrine TNF-alpha secretion resulting from IgE/FcepsilonRI-dependent activation plays a critical role in suppressing TLR9-dependent responses in pDCs that normally promote T(H)1 activity.
    The Journal of allergy and clinical immunology 03/2008; 121(2):486-91. · 12.05 Impact Factor
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2008; 121(2).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2008; 121(2).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2007; 119(1).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2007; 119(1).
  • Journal of Allergy and Clinical Immunology - J ALLERG CLIN IMMUNOL. 01/2007; 119(1).

Publication Stats

265 Citations
14 Downloads
767 Views
119.09 Total Impact Points

Institutions

  • 2008–2011
    • Johns Hopkins Medicine
      • Department of Pediatrics
      Baltimore, MD, United States
  • 2003–2011
    • Johns Hopkins University
      • Department of Medicine
      Baltimore, MD, United States
  • 2010
    • Mount Sinai School of Medicine
      Manhattan, New York, United States