Sensitized Lymphocytes Partially Transfer Rat Pulmonary Late Responses
Format of Original
Journal of Allergy and Clinical Immunology
Original Item ID
doi: 10.1016/0091-6749(94)90221-6; Shelves: RC583 .J Memorial Periodicals
We have demonstrated that, following antigen challenge, rats sensitized to preferentially produce IgE antibody develop late (8-24 h) responses characterized by airway obstruction (AO), hyperresponsiveness (HR), and tissue inflammation (TI). To evaluate mechanisms responsible for these changes, we have begun a series of passive transfer experiments. We initially established that antigen-specific IgE and IgG antibody are insufficient stimuli to allow the development of the late response following antigen challenge. in this series of experiments, we attempted to transfer a late response using sensitized lymphocytes. Splenic lymphocytes were obtained from Lewis rats sensitized (IgE) to dinitrophenol-ovalbumin (DNP-OA); cultured cells demonstrated a significant proliferative response to OA in vitro. Naive rats were injected with sensitized lymphocytes (107cells iv) that had been cultured with OA for 24 hours; in some experiments CD8+ lymphocytes were depleted from the cultured cell populations using magnetic bead methods. An additional subset of rats received both lymphocytes and IgE rich serum from sensitized donor rats. After transfer, recipient rats were challenged with 1 or 2 tracheal insufflations of OA or BSA. One day after antigen challenge, rats were evaluated for AO (resistance & compliance), HR (iv methacholine), and TI (inflammation scores of lung sections). Inflammation scores were significantly increased (fig.) in OA challenged rats (n=11) compared with BSA controls (n=5); OA pulmonary responses were not noticeably enhanced by CD8+ cell depletion or by addition of IgE rich serum. Despite the induction of a pulmonary inflammatory response, no significant AO or HR was detected in OA-challenged rats, although the OA-induced inflammation was less intense than occurs in actively sensitized animals. Thus, one (TI) of the three (TI, OA, HR) components of rat late responses can be transferred with sensitized lymphocytes, whereas none can be transferred with IgE or IgG isotypes alone.