OBJECTIVE: To evaluate the local immune response after allergic sensitization and challenge in the lungs of mice.METHODS: C57BL/6 mice were sensitized with keyhole limpet hemocyanin (KLH) by intratracheal instillation and challenged 2 approximately 4 weeks later. Bronchoalveolar lavage fluid (BALF) and plasma were collected and cells from the lung-associated lymph node (LALN), the lungs and the spleen were cultured and collected. Anti-KLH IgA, total IgA and albumin levels were measured by ELISA.RESULTS: Intratracheal instillation of KLH induced local BAL antigen-specific IgA response, and further challenge expanded this response. The ratio of anti-KLH IgA/albumin in BALF was significantly higher than that in serum after both sensitization and challenge by KLH. In vitro, cells from the LALN and the lungs released anti-KLH IgA after sensitization and challenge by KLH, but spleen cells released lower levels of anti-KLH IgA compared to the LALN and the lungs.CONCLUSIONS: Allergic sensitization by intratracheal instillation of KLH into the mouse lungs induced a local pulmonary response of specific IgA, and it was amplified by challenge with KLH. The accumulation of anti-KLH IgA in the respiratory lumen was the result of local production but not the result of simple transudation or leakage from the serum. The LALN and the lung lymphocytes were major sources of anti-specific IgA.
Animals Antibodies