title: Antigen-pulsed bone marrow-derived and pulmonary dendritic cells promote Th2 cell responses and immunopathology in lungs during the pathogenesis of murine Mycoplasma pneumonia.
abstract: Mycoplasmas are a common cause of pneumonia in humans and animals, and attempts to create vaccines have not only failed to generate protective host responses, but they have exacerbated the disease. Mycoplasma pulmonis causes a chronic inflammatory lung disease resulting from a persistent infection, similar to other mycoplasma respiratory diseases. Using this model, Th1 subsets promote resistance to mycoplasma disease and infection, whereas Th2 responses contribute to immunopathology. The purpose of the present study was to evaluate the capacity of cytokine-differentiated dendritic cell (DC) populations to influence the generation of protective and/or pathologic immune responses during M. pulmonis respiratory disease in BALB/c mice. We hypothesized that intratracheal inoculation of mycoplasma Ag-pulsed bone marrow-derived DCs could result in the generation of protective T cell responses during mycoplasma infection. However, intratracheal inoculation (priming) of mice with Ag-pulsed DCs resulted in enhanced pathology in the recipient mice when challenged with mycoplasma. Inoculation of immunodeficient SCID mice with Ag-pulsed DCs demonstrated that this effect was dependent on lymphocyte responses. Similar results were observed when mice were primed with Ag-pulsed pulmonary, but not splenic, DCs. Lymphocytes generated in uninfected mice after the transfer of either Ag-pulsed bone marrow-derived DCs or pulmonary DCs were shown to be IL-13(+) Th2 cells, known to be associated with immunopathology. Thus, resident pulmonary DCs most likely promote the development of immunopathology in mycoplasma disease through the generation of mycoplasma-specific Th2 responses. Vaccination strategies that disrupt or bypass this process could potentially result in a more effective vaccination.
authors: Division of Infectious Diseases, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390;
authors: Nicole A
authors: NA
authors: Dobbs
authors: Department of Ophthalmology, Xiangya Hospital of Central South University, Changsha 410008, China;
authors: Xia
authors: X
authors: Zhou
authors: Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107; and.
authors: Mark
authors: M
authors: Pulse
authors: Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107; and.
authors: Lisa M
authors: LM
authors: Hodge
authors: Division of Genomics, Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294.
authors: Trenton R
authors: TR
authors: Schoeb
authors: Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, TX 76107; and jerry.simecka@unthsc.edu.
authors: Jerry W
authors: JW
authors: Simecka
mesh_terms: D000281:Administration, Intranasal; D000818:Animals; D000942:Antigens, Bacterial / Q000008:administration & dosage*; D001854:Bone Marrow Cells / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology / Q000637:transplantation; D005260:Female; D007442:Intubation, Intratracheal; D008168:Lung / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D016513:Mice, SCID; D045803:Mycoplasma pulmonis / Q000276:immunology* / Q000472:pathogenicity; D011019:Pneumonia, Mycoplasma / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D018418:Th2 Cells / Q000276:immunology* / Q000473:pathology / Q000637:transplantation
chemical_list: D000942:Antigens, Bacterial