Recruitment of antibody-forming cells in the lung after local immunization is nonspecific.

The deposition of particulate antigen into the dog lung induces a large accumulation of antigen-specific-forming cells in immunized lung lobes. The results of our previous studies with dogs indicate that these cells are recruited to the immunized lung lobes from the blood. The present study was designed to determine if the recruitment of immune cells to the lung is antigen-specific, or if changes occur in the lung after immunization that allow immune cells to enter the lung nonspecifically. Dogs were immunized in the left and right cardiac lung lobes with antigenically different particulate antigens. The number of lymphoid cells producing antibody to each antigen and the concentrations of antigen-specific antibody were measured in the immunized lung lobes and in a control lung lobe at 5 through 14 days after immunization. Similar numbers of antibody-forming cells and concentrations of antibody to both antigens were found in each immunized lung lobe, regardless of which antigen was used for immunization. These results indicate that antigen exposure alters the lung to allow a nonspecific recruitment of immune cells from the blood into the immunized lung lobes, regardless of antigen specificity. These data also provide further evidence that the antibody-forming cells found in the lung lavage fluid after localized immunization are produced in the thoracic lymph nodes or other systemic lymphoid tissues, rather than locally in lymphoid tissues in the deep lung.