Alveolar macrophages in pulmonary immune responses. I. Role in the initiation of primary immune responses and in the selective recruitment of T lymphocytes to the lung.
Antigen inoculated intratracheally (IT) into animals can induce primary immune responses and selectively recruit specific T cells to the lung. In the current study, the role of alveolar macrophages (AM) in these two responses was investigated. Antigen-pulsed bronchoalveolar cells (BAC) inoculated IT into guinea pigs generated a population of immune T cells that proliferated in vitro on reexposure to antigen-pulsed macrophages (Mø). The possibility that antigen-pulsed donor BAC shed antigen that was subsequently processed and presented by host Mø was ruled out by genetic experiments. Thus, peritoneal exudate lymphocytes (PEL) from (2 X 13)F1 guinea pigs primed with antigen-pulsed BAC from strain 2 animals responded preferentially to antigen-pulsed strain 2 Mø rather than to antigen-pulsed strain 13 Mø. In a second set of studies, antigen-pulsed BAC inoculated IT into guinea pigs selectively recruited antigen-specific T cells to the lung. Genetic experiments verified that inoculated BAC were the source of the antigen-presenting cells responsible for selective recruitment. Thus, antigen-pulsed strain 2 BAC inoculated IT recruited a greater proportion of (2 X 13)F1 T cells that recognized antigen in the context of strain 2 Mø than F1 T cells that recognized antigen on strain 13 Mø. Taken together, these studies suggest that AM contribute to the regulation of pulmonary immunity by both inducing T lymphocyte immunity and selectively recruiting specific T cells to the lung.
D000818:Animals; D000941:Antigens / Q000008:administration & dosage; D002465:Cell Movement; D000939:Epitopes; D006168:Guinea Pigs; D007116:Immunization, Passive; D008168:Lung / Q000276:immunology*; D008213:Lymphocyte Activation; D008262:Macrophage Activation; D008264:Macrophages / Q000145:classification / Q000276:immunology*; D011650:Pulmonary Alveoli / Q000166:cytology; D013601:T-Lymphocytes / Q000276:immunology* / Q000502:physiology
D000941:Antigens; D000939:Epitopes