Mikila R. Jacobsonb

Background: Local tissue eosinophilia and Th2 cytokines are characteristic features of seasonal allergic rhinitis. Airway remodelling is a feature of asthma whereas evidence for remodelling in allergic rhinitis (AR) is conflicting.Objective: By use of a novel human repetitive nasal allergen challenge (RAC) model, we evaluated the relationship between allergic inflammation and features of remodelling in AR.Methods: Twelve patients with moderate–severe AR underwent 5 alternate day challenges with diluent which after 4 weeks were followed by 5 alternate day challenges with grass pollen extract. Nasal symptoms, Th1/Th2 cytokines in nasal secretion and serum were evaluated. Nasal biopsies were taken 24 hours after the 1st and 5th challenges with diluent and with allergen. Sixteen healthy controls underwent a single challenge with diluent and with allergen. Using immunohistochemistry, epithelial and submucosal inflammatory cells and remodelling markers were evaluated by computed image analysis.Results: There was an increase in early and late‐phase symptoms after every allergen challenge compared to diluent (both P < .05) with evidence of both clinical and immunological priming. Nasal tissue eosinophils and IL‐5 in nasal secretion increased significantly after RAC compared to corresponding diluent challenges (P < .01, P = .01, respectively). There was a correlation between submucosal mast cells and the early‐phase clinical response (r = 0.79, P = .007) and an association between epithelial eosinophils and IL‐5 concentrations in nasal secretion (r = 0.69, P = .06) in allergic rhinitis. No differences were observed after RAC with regard to epithelial integrity, reticular basement membrane thickness, glandular area, expression of markers of activation of airway remodelling including α‐SMA, HSP‐47, extracellular matrix (MMP7, 9 and TIMP‐1), angiogenesis and lymphangiogenesis for AR compared with healthy controls.Conclusion: Novel repetitive nasal allergen challenge in participants with severe persistent seasonal allergic rhinitis resulted in tissue eosinophilia and increases in IL‐5 but no structural changes. Our data support no link between robust Th2‐inflammation and development of airway remodelling in AR.

Rationale: Increases in airway smooth muscle, extracellular matrix, and vascularity are prominent features of airway remodeling in asthma, whereas the extent of such remodeling in patients with persistent allergic rhinitis (PAR) is unknown. Objectives: To test the hypothesis that upper airway remodeling is a feature of PAR. Methods: Total nasal symptoms scores, nasal biopsies, and Th1 and Th2 cytokines from nasal lavage were assessed in subjects with severe PAR (n = 46) and healthy control subjects (n = 19). Angiolymphangiogenesis was examined using immunohistochemistry staining against CD31 (vascular endothelial cells), vascular endothelial growth factor-A, and D2-40 (lymphatic endothelial cells). Collagen and extracellular matrix proteins, such as heat shock protein-47 (markers of collagen synthesis), matrix metalloproteinase-9, and tissue inhibitor metalloproteinase-1, and α-smooth muscle actin (myofibroblasts) were evaluated as markers of activation of upper airway remodeling using image analysis, together with reticular basement membrane thickness, mucus gland area, collagen area, and submucosal effector inflammatory cells. Measurements and Main Results: Total nasal symptoms scores, visual analog scale, and total quality of life were significantly higher in PAR compared with healthy control subjects (P < 0.0001). Nasal lavage cytokine levels of IL-4 (P < 0.01), IL-5, and IL-13 (P < 0.001, respectively) were significantly higher in PAR compared with healthy control subjects. In addition there was an increase in submucosal eosinophils (P = 0.06). No statistical difference in terms of angiogenesis, lymphangiogenesis, deposition of extracellular matrix, collagen markers, reticular basement membrane thickness, or glandular percentage area was observed between PAR and healthy control subjects. Conclusions: Our data suggest that tissue remodeling is not a feature of PAR and argues that in contrast to asthma, targeting remodeling in allergic rhinitis may not be appropriate as a therapeutic approach.

Background: Myeloid (m) and plasmacytoid (p) dendritic cells (DCs) regulate immune responses to allergens, whereas it remains unclear whether abnormal DC function characterizes patients with airway allergy and whether putative dysfunction exists only in target organs. To evaluate DC function from patients with allergic rhinitis (AR), we assessed nasal, cutaneous as well as blood DCs after in vivo and in vitro allergen challenge, respectively.Methods: DCs were immunostained in nasal and skin tissues, and cytokine expression was assessed by dual immunofluorescence. Cytokine production and regulation of cocultured peripheral CD4+ T cells were assayed by ELISA.Results: In AR patients, local allergen challenge resulted in increases in pDC and mDC numbers at 8 h in the nasal mucosa and at 8–48 h in the skin. Defects in IL‐10 and IFN‐α were observed in both organs from AR. Blood mDCs from AR exhibited reduced IL‐10 and IL‐12 expression. The capacity of activated pDCs from AR to produce IFN‐α and to trigger IL‐10 by allogeneic CD4⁺ T cells was diminished, whereas mDCs from these patients supported Th2‐ and Th17‐cell differentiation.Conclusion: In allergic rhinitis, DCs are altered not only locally but also in the systemic circulation. mDCs and pDCs increased in airway and skin tissues exposed to the allergen and displayed reduced production of IL‐10 and ‘type 1 signals’ (IL‐12, IFN‐α) both locally and in blood. Functional studies showed that this results in preferential Th2/Th17‐cell polarization and impaired generation by blood DCs of IL‐10+ T cells, linking systemic DC dysfunction and biased T‐cell responses.

Summary: Background: T‐bet and GATA‐3 are transcriptional factors involved in Th1 and Th2 cell differentiation, although their concomitant roles at protein levels in target organs during human allergic disease have not been assessed.Objectives: We investigated the expression of T‐bet and GATA‐3 in nasal and cutaneous models of Th2 (grass‐pollen allergen) and a cutaneous model of Th1 (PPD) responses in man.Methods: Nasal biopsies were obtained at 8 h and skin biopsies at 8 and 48 h after allergen and PPD challenges, respectively, from 10 allergic rhinitics and 6 non‐atopic controls. T cells were assessed using immunofluorescence microscopy.Results: There were increases in CD3⁺STAT6⁺cells (P = 0.01 for nose and skin) and CD3⁺GATA3⁺cells (P = 0.03 for skin) in response to allergen compared with diluent in allergics. When compared with non‐atopics after allergen challenge the difference between the two groups was also significant for CD3⁺STAT6⁺ (P = 0.001 and 0.03) and for CD3⁺GATA3⁺cells (P = 0.04 and 0.001) for nose and skin respectively. Following PPD challenge CD3⁺STAT4⁺cells and CD3⁺T‐bet⁺cells increased in both groups compared with diluent (P = 0.02 and 0.03 for both TFs), whereas only CD3⁺T‐bet⁺ cells were significantly greater in non‐atopics compared with allergics (P = 0.04). The ratio of GATA3⁺:T‐bet⁺ T cells in allergen‐induced responses was significantly greater in the allergics (P = 0.008 and 0.01 nose and skin respectively), whereas the ratio of T‐bet:GATA3⁺T cells was significantly higher in the non‐atopics during PPD‐induced responses (P = 0.003).Conclusions and Clinical Relevance: Dysregulation of Th1 transcription may contribute to heightened expression of STAT6 and GATA3 leading to exaggerated Th2‐driven manifestations of allergic disease.

To cite this article: Banfield G, Watanabe H, Scadding G, Jacobson MR, Till SJ, Hall DA, Robinson DS, Lloyd CM, Nouri‐Aria KT, Durham SR. CC Chemokine Receptor 4 (CCR4) in human allergen‐induced late nasal responses. Allergy 2010; 65: 1126–1133. Background:  CC Chemokine receptor 4 (CCR4) is preferentially expressed on Th2 lymphocytes. CCR4‐mediated inflammation may be important in the pathology of allergic rhinitis. Disruption of CCR4 – ligand interaction may abrogate allergen‐induced inflammation.Methods:  Sixteen allergic rhinitics and six nonatopic individuals underwent both allergen and control (diluent) nasal challenges. Symptom scores and peak nasal inspiratory flow were recorded. Nasal biopsies were taken at 8 h post challenge. Sections were immunostained and examined by light or dual immunofluorescence microscopy for eosinophils, T‐lymphocytes, CCR4⁺CD3⁺ and CXCR3⁺CD3⁺ cells and examined by in situ hybridization for CCR4, IL‐4 and IFN‐γ mRNA⁺ cells. Peripheral blood mononuclear cells were obtained from peripheral blood of nine normal donors and the CCR4⁺CD4⁺ cells assessed for actin polymerization in response to the CCR4 ligand macrophage‐derived chemokine (MDC/CCL22) and the influence of a CCR4 antagonist tested.Results:  Allergic rhinitics had increased early and late phase symptoms after allergen challenge compared to diluent; nonatopics did not respond to either challenge. Eosinophils, but not total numbers of CD3⁺ T cells, were increased in rhinitics following allergen challenge. In rhinitics, there was an increase in CCR4⁺CD3⁺ protein‐positive cells relative to CXCR3⁺CD3⁺ cells; CCR4 mRNA+ cells were increased and IL‐4 increased to a greater extent than IFN‐γ. CCR4⁺CD4⁺ T cells responded to MDC in vitro, and this response was inhibited by the selective CCR4 antagonist.Conclusion:  Lymphocyte CCR4 expression is closely associated with induction of human allergen‐induced late nasal responses. Blocking CCR4‐ligand interaction may provide a novel therapeutic approach in allergic disease.

Summary: Background The mechanisms of sublingual immunotherapy (SLIT) are less well understood than those of subcutaneous immunotherapy (SCIT).Objectives To determine the effects of grass‐pollen SLIT on oral mucosal immune cells, local regulatory cytokines, serum allergen‐specific antibody subclasses and B cell IgE‐facilitated allergen binding (IgE‐FAB).Methods Biopsies from the sublingual mucosa of up to 14 SLIT‐treated atopics, nine placebo‐treated atopics and eight normal controls were examined for myeloid dendritic cells (mDCs) (CD1c), plasmacytoid dendritic cells (CD303), mast cells (AA1), T cells (CD3) and Foxp3 using immunofluorescence microscopy. IL‐10 and TGF‐β mRNA expression were identified by in situ hybridization. Allergen‐specific IgG and IgA subclasses and serum inhibitory activity for binding of allergen‐IgE complexes to B cells (IgE‐FAB) were measured before, during and on the completion of SLIT.Results Foxp3⁺ cells were increased in the oral epithelium of SLIT‐ vs. placebo‐treated atopics (P=0.04). Greater numbers of subepithelial mDCs were present in placebo‐treated, but not in SLIT‐treated, atopics compared with normal controls (P=0.05). There were fewer subepithelial mast cells and greater epithelial T cells in SLIT‐ compared with placebo‐treated atopics (P=0.1 for both). IgG₁ and IgG₄ were increased following SLIT (P1 and IgA₂ were increased during SLIT (PConclusions SLIT with grass pollen extract is associated with increased Foxp3⁺ cells in the sublingual epithelium and systemic humoral changes as observed previously for SCIT. Cite this as: G. W. Scadding, M. H. Shamji, M. R. Jacobson, D. I. Lee, D. Wilson, M. T. Lima, L. Pitkin, C. Pilette, K. Nouri‐Aria and S. R. Durham, Clinical & Experimental Allergy, 2010 (40) 598–606.