Allergen‐Induced Synthesis of Interleukin‐5, but not of IgE, is a Key Mechanism Linked to Symptomatic Episodes of Seasonal Allergic Rhinitis in Sensitized Individuals

Abstract

Some individuals with detectable levels of Japanese cedar (Criptomeria japonica) pollen-specific immunoglobulin (Ig)E in serum have no apparent nasal symptoms during the pollen season. The response of CD4+ T-helper (Th) cells to the pollen allergen might differ fundamentally between asymptomatic and symptomatic individuals who are already sensitized to the pollen. The aim of this study was to discern the possible differences in responses of peripheral blood mononuclear cells (PBMCs) to the pollen allergen between asymptomatic and symptomatic subjects who have been sensitized to the pollen. This study included 20 non-atopic healthy volunteers (non-atopic group) and 48 patients who had detectable levels of the pollen-specific IgE before the pollen season in 1997. In the review of nasal symptoms during the pollen season 1997, 24 patients had typical symptoms of seasonal allergic rhinitis (symptomatic group), and the remainder had no seasonal aggravation of nasal symptoms (asymptomatic group). Peripheral blood mononuclear cells (1.0 x 10(7) cells/well) were obtained from each individual during the pollen season and cultured in the absence or presence of 12.5 microg of Cry j 1 for 4 days. The concentrations of IgE, interleukin-5 (IL-5), and interferon-gamma (IFN-gamma) in the culture supernatants were measured. The levels of IgE produced by Cry j 1-stimulated PBMCs of the asymptomatic and symptomatic groups were significantly higher than those of the non-atopic group, but did not differ between the asymptomatic and symptomatic groups. The levels of IL-5 produced by Cry j 1-stimulated PBMCs did not differ significantly between the non-atopic group and the asymptomatic group, but the levels of IL-5 were significantly higher in the symptomatic group than in the asymptomatic group as well as the non-atopic group. The levels of IFN-gamma produced by Cry j 1-stimulated PBMCs did not differ significantly among the three groups. In conclusion, our study has suggested that Japanese cedar pollen-induced synthesis of IL-5, but not of IgE or IFN-gamma, is likely to be a key mechanism linked to the symptomatic episode of seasonal allergic rhinitis in individuals sensitized to the pollen.

The Herbal Medicine Shoseiryu-to inhibits Allergen-induced Synthesis of Tumour Necrosis Factor Alpha by Peripheral Blood Mononuclear Cells in Patients with Perennial Allergic Rhinitis

“…According to current thinking, atopic allergy might be defined as a TH2 cell or allergen-induced TH2 response predominant inflammatory disease. A key factor involved in allergic diseases is undoubtedly allergen-specific IgE to a particular environmental allergens (24), and PBMCs from allergic patients produce larger amounts of IgE than those from non-atopic individuals (16,25). In the present study, the level of IgE produced by PBMCs in the presence of shoseiryu-to were significantly lower than those in the absence of the agent, although the significance was weak (p =0.0415).…”

“…Expression of mRNA for IL-5 has been detected in bronchial biopsies of asthmatic patients, and the expression of IL-5 mRNA has tended to increase in severe disease (27). IL-5 is a key cytokine linked to symptomatic episodes of allergic rhinitis and asthma in sensitized individuals (25,28). In addition, treatment with anti-IL-5mAb could inhibit the development of hyper-responsiveness (29).…”

Examination of seasonal difference in serum interleukin-17 and interleukin-5 concentrations in ragweed-sensitized children

“…These authors have found that neutrophils were regulated through activation of IL-8. Ex vivo stimulation of peripheral blood mononuclear cells of patients with symptoms of seasonal allergic rhinitis with Japanese cedar pollen allergen Cry j induced synthesis of IL-5 (Ohashi et al 1998).…”

Seasonal Changes in Phytohemagglutinin-induced Cytokine Synthesis by Peripheral Blood Lymphocytes of Patients with Seasonal Allergic Rhinitis due to Japanese Cedar Pollens

“…The details and justification of the methods employed in this study have been described elsewhere (19,(22)(23)(24).…”

“…The seasonal rise in TH2-type cytokines in seasonal allergic rhinitis is likely to be due to the increased reactivity of TH cells in response to the natural allergen exposure during the pollen season. Indeed, allergen-induced synthesis of TH2-type cytokines by TH cells is significantly greater in patients with seasonal allergic rhinitis than in non-atopic individuals (19). However, it remains unclear whether this increased reactivity of TH cells of patients with seasonal allergic rhinitis is an allergen-specific or a general immune enhancement.…”