Anti-allergic potential of oligomannose-coated liposome-entrapped Cry j 1 as immunotherapy for Japanese cedar pollinosis in mice

Administration of oligomannose-coated liposomes (OMLs) in mice can induce Th1 immune responses against antigens entrapped in the OMLs. In the present study, we investigated the anti-allergic effect of treatment with oligomannose-coated liposomes (OMLs) with entrapped Cry j 1, a major allergen of Japanese cedar pollen (Cry j 1/OMLs), in Balb/c mice sensitized with Cry j 1. Pretreatment of unsensitized mice with Cry j 1/OMLs repressed the elevation of total and allergen-specific IgE levels in sera elicited in response to subsequent sensitization with Cry j 1. Cry j 1-specific IgG1 in sera also decreased in Cry j 1/OML-treated mice, while the levels of Cry j 1-specific IgG2a in these mice significantly increased after sensitization with Cry j 1. In addition, Cry j 1/OML-treated mice showed high IFN-γ production from spleen cells and low IL-4/IFN-γ and IL-5/IFN-γ ratios in response to in vitro stimulation with Cry j 1. These results indicate that allergen-specific Th1 immune responses predominate over Th2 responses and control IgE elevation in Cry j 1/OML-treated mice. The anti-allergic effect of Cry j 1/OML determined by suppression of serum IgE levels was also observed in Cry j 1-presensitized mice after challenge with antigen. Thus, Cry j 1/OMLs may be useful for immunotherapeutic control of allergic reactions to Japanese cedar pollinosis.