ADOPTIVE TRANSFER OF ALLERGIC AIRWAY RESPONSES WITH SENSITIZED LYMPHOCYTES IN BN RATS

To evaluate the role of lymphocytes in the pathogenesis of allergic br onchoconstriction, we investigated whether allergic airway responses a re adoptively transferred by antigen-primed lymphocytes in Brown Norwa y (BN) rats. Animals were actively sensitized to ovalbumin (OA) or sha m sensitized, and 14 d later mononuclear cells (MNCs) were isolated fr om intrathoracic lymph nodes, passed through a nylon wool column, and transferred to naive syngeneic rats. Recipients were challenged with a erosolized OA or bovine serum albumin (BSA) (5% wt/vol) and analyzed f or changes in lung resistance (R(L)), airway responsiveness to inhaled methacholine (MCh), and bronchoalveolar lavage (BAL) cells. Recipient s of MNCs from sensitized rats responded to OA inhalation and exhibite d sustained increases in R(L) throughout the 8-h observation period, b ut without usual early airway responses. Recipients of sham-sensitized MNCs or BSA-challenged recipients failed to respond to antigen challe nge. At 32 h after OA exposure, airway responsiveness to MCh was incre ased in four of seven rats that had received sensitized MNCs (p = 0.03 5). BAL eosinophils increased at 32 h in the recipients of both sensit ized and sham-sensitized MNCs. However, eosinophil numbers in BAL were inversely correlated with airway responsiveness in the recipients of sensitized MNCs (r = 0.788, p = 0,036). OA-specific immunoglobulin E ( IgE) was undetectable by enzyme-linked immunosorbent assay (ELISA) or passive cutaneous anaphylaxis (PCA) in recipient rats following adopti ve transfer. In conclusion, allergic late airway responses (LAR) and c holinergic airway hyperresponsiveness, but not antigen-specific IgE an d early responses, were adoptively transferred by antigen-primed lymph ocytes in BN rats. This study suggests a central role of T lymphocytes in allergic airway responses in this experimental model.