Cellular Immunity Induced by Lung Immunization of Fischer 344 Rats

This study describes immunologic response in lung-associated lymph nodes, spleen, cervical lymph nodes and lung lavage cells of rats immunized by intratracheal instillation of BCG-sheep red blood cell (SRBC) suspensions. At 4 through 17 days after immunization, the number of anti-SRBC IfM and IgG antibody-forming cells was significantly increased only in the lung-associated lymph nodes, indicating that these tissues retain the particulate antigen that was deposited in the lung. In contrast, cellular immunity was found initially in the spleen, with significant responses in the lungs and in the lung-associated lymph nodes on 13--19 days after immunization. Our data indicated that the lung-associated lymph nodes are probably the initial site for the production of antigen-sensitive lymphocytes for both antibody and cellular immunity after lung immunization. Cells responsible for cellular immunity appear to migrate to the spleen, where further cell division take place.