Cellular changes in the bronchoalveolar lavage (BAL) of pigs, following immunization by the enteral or respiratory route

Abstract

SUMMARYNormal young pigs were immunized by the oral or aerogenic route with the viable or inactivated lungpathogenic bacterium Actinohaciltus (Haemophilus) pleuropneumoniae. Three weeks Uiler the cellular composition as well as the lymphocyte subset composition of the bronchoalveolar space were examined by BAL. Lymphocytes in the lavage increased significantly, including CD4' and CD8' T cells. After oral immunization a dramatic increase of plasma cells and lymphoid blasts was found. Among immunoglobulin-positive lymphocytes IgG' cells showed the most pronounced increase. For most lymphocyte subsets there was no difference between viable and inactivated bacteria. Oral immunization with a lung-pathogenic bacterium results in increased numbers of lymphocytes in the bronchoalveolar space and might play a critical role in proteetion against lower respiratory tract infections.

Evidence for a common mucosal immune system in the pig

“…Oral immunization with the Actinobacillus pleuropneumoniae (live or killed) and the impact on lymphocyte subset distribution in the bronchoalveolar space and ASCs in lavage fluid and sera (Delventhal et al, 1992;Pabst et al, 1995) In these experiments, four month old German Landrace pigs from an SPF breeding farm were used (Delventhal et al, 1992;Pabst et al, 1995). A 'lavage' control group (n = 5) were lavaged at week one, five and six (without being immunized) (Delventhal et al, 1992;Pabst et al, 1995). Another 'non-immunization' control group was lavaged then infected by aerosol challenge and lavaged again one week later.…”

“…Another 'non-immunization' control group was lavaged then infected by aerosol challenge and lavaged again one week later. The experimental pigs were lavaged followed by orally immunized with 10 11 active or inactive (irradiated) bacteria (Delventhal et al, 1992;Pabst et al, 1995). All groups (with the exception of the lavage control group) were infected by aerosol challenge with 10 8 viable APP at week five then lavaged one week later.…”

Oral and aerosol immunization with viable or inactivatedActinobacillus pleuropneumoniaebacteria: antibody response to capsular polysaccharides in bronchoalveolar lavage fluids (BALF) and sera of pigs

“…We used the BAL technique to determine the effects ofaerogenieororal immunization with A. pleuropneumoniae on ee!l composition in lavage fluids. A significant increase of immunocompetent cells in the bronchoaiveolar airways was demonstrated after oral and aerosol immunization [20].…”

“…Pigs accepted for the study did not show any exudate and inflammatory signs in traehea and main bronchi visible by bronchoseopy. and were found with ^90% alveolar maerophages in the differential cell count of the BALF [20]. Within 1 week after BAL the pigs were randomly divided in five groups and subsequently immunized with A. pleuropneumoniae.…”

“…Bronchoaiveolar lavage BAL was performed in anaesthetized pigs using flexible fibreoptie bronchoscopes as described previously [20]. Briefly, the pigs were anaesthetized and the tip of the bronchoscope was direeted into ihe right middle lobar bronchus.…”