title: Naturally acquired Pneumocystis carinii pneumonia in gene disruption mutant mice: roles of distinct T-cell populations in infection.
abstract: When kept under strict specific-pathogen-free conditions, H-21-Abeta (Abeta(-/-),T-cell receptor beta (TCRbeta(-/-)), and recombinase-activating gene 1 (RAG-1(-/-) gene disruption mutant mice, deficient in conventional CD4+ T cells, TCRalphabeta cells, and all peripheral T and B lymphocytes, respectively, consistently developed lethal Pneumocystis carinii pneumonia through natural infection. The most severe symptoms appeared in RAG-1(-/-) mutants. In contrast, TCRdelta(-/-) and beta2-microglobulin(-/-)(beta2m-/-) mutants, deficient in TCRgammadelta cells and conventional CD8alphabeta+ TCRalphabeta cells, respectively, were fully resistant to infection. Our data indicate not only the insufficiency but also the dispensability of CD8 alphabeta+TCRalphabeta cells and of TCRgammadelta lymphocytes in resistance to P. carinii infection. Under disease conditions, large numbers of unusual single-positive CD4+ and CD8alphabeta+ as well as double-negative TCRgammadelta subpopulations of cells accumulated in lungs of TCRbeta(-/-) mutants. This accumulation was consistently accompanied by a drastic increase in the pulmonary B-cell population. In contrast, CD8alphabeta+ TCR alpha beta cells, but no B cells, appeared in lungs of parasitized Abeta (-/-) mutants. Since lung damage and parasite numbers were less prominent in morbid TCRbeta(-/-) and Abeta(-/-) mutants than in diseased RAG-1(-/-) mice, the remaining lymphocytes accumulating in lungs of the former two mutants seem to perform residual resistance functions.
authors: Department of Immunology, University of Ulm, Germany.
authors: R
authors: R
authors: Hanano
authors: K
authors: K
authors: Reifenberg
authors: S H
authors: SH
authors: Kaufmann
mesh_terms: D000818:Animals; D001483:Base Sequence; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004269:DNA, Bacterial / Q000302:isolation & purification; D006183:H-2 Antigens / Q000235:genetics*; D018398:Homeodomain Proteins; D007150:Immunohistochemistry; D008168:Lung / Q000382:microbiology / Q000473:pathology; D051379:Mice; D008817:Mice, Mutant Strains; D008969:Molecular Sequence Data; D009017:Morbidity; D011010:Pneumocystis / Q000235:genetics / Q000302:isolation & purification; D011020:Pneumonia, Pneumocystis / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D016133:Polymerase Chain Reaction; D011506:Proteins / Q000235:genetics*; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D001613:beta 2-Microglobulin / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D006183:H-2 Antigens; D018398:Homeodomain Proteins; D011506:Proteins; D016693:Receptors, Antigen, T-Cell, alpha-beta; D001613:beta 2-Microglobulin; C064658:RAG-1 protein