Transfer of allergic airway responses with serum and lymphocytes from rats sensitized to dust mite

Abstract

House dust mite (HDM) antigen is one of the most common allergens associated with extrinsic asthma. In a model of allergic lung disease, Brown Norway (BN) rats sensitized to HDM with alum and Bordetella pertussis adjuvants produce high levels of IgE antibody and experience bronchoconstriction, increased airway hyperresponsiveness (AHR) to acetylcholine (ACh), and pulmonary inflammation after antigen challenge. The purpose of this study was to determine whether these asthmatic symptoms could be transferred from sensitized animals to naive recipients via humoral or cellular factors. Syngeneic recipient rats were injected (intraperitoneally with 4 x 10(7) cells (precultured overnight with either HDM or bovine serum albumin [BSA]) from lymph nodes of sensitized or control rats, respectively. Other groups received a tail-vein injection of serum from either HDM-sensitized or control rats. Antigen challenge in rats injected with sensitized cells caused increases in pulmonary inflammation and in AHR, but no changes in immediate bronchoconstriction as compared with control recipients. Antigen challenge in serum recipients resulted in immediate bronchoconstriction but had no effect on AHR or on pulmonary inflammation. These data show that immune-mediated lung inflammation and AHR are promoted by antigen-specific lymphocytes, whereas immediate allergic responses are caused by serum factors.