title: Alterations in T lymphocyte profiles of bronchoalveolar lavage fluid from SIV- and Pneumocystis carinii-coinfected rhesus macaques.
abstract: The goal of this study was to examine SIV- and Pneumocystis carinii-coinfected rhesus macaques as a model of P. carinii infection in HIV-seropositive humans. The influence of P. carinii infection on the cellular composition of bronchoalveolar lavage (BAL) fluid from SIV-infected and normal rhesus macaques was examined by flow cytometric analysis and polymerase chain reaction (PCR). BAL fluid from SIV- and P. carinii coinfected macaques showed a substantial T lymphocyte influx composed of more than 90% CD8+ T cells. These results are in contrast to BAL fluid from SIV-infected macaques with no detectable P. carinii-specific PCR product, where CD4+ T cells were present in significant numbers and the CD8+ T cell population was less than 70% of total CD3+ lymphocytes. We observed no significant differences in peripheral blood CD4+ or CD8+ T cell levels in the SIV-infected animals, regardless of P. carinii status, indicating that the CD8+ T cell infiltration in the lungs of the P. carinii-positive animals was likely the result of P. carinii infection. These results demonstrate that although peripheral blood CD4+ T cell levels are predictive of susceptibility to P. carinii infection in this model, the levels are not reflective of the T cell profile in the lung during SIV and P. carinii coinfection. The SIV- and P. carinii-coinfected macaques showed a spectrum of lung disease severity that was histologically similar to human P. carinii pneumonia (PCP). Interestingly, even mild P. carinii infection was sufficient to alter the normal CD4+/CD8+ T cell profiles in the lungs of SIV-infected rhesus macaques. These results are similar to immunologic findings in human AIDS-associated PCP and support the usefulness of this model in the study of immune responses to P. carinii.
authors.affiliation: Department of Molecular Genetics and Biochemistry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Denise A
authors.initials: DA
authors.lastname: Croix
authors.forename: Kathryn
authors.initials: K
authors.lastname: Board
authors.forename: Saverio
authors.initials: S
authors.lastname: Capuano
authors.forename: Michael
authors.initials: M
authors.lastname: Murphey-Corb
authors.forename: Constantine G
authors.initials: CG
authors.lastname: Haidaris
authors.forename: Joanne L
authors.initials: JL
authors.lastname: Flynn
authors.forename: Todd
authors.initials: T
authors.lastname: Reinhart
authors.forename: Karen A
authors.initials: KA
authors.lastname: Norris
mesh_terms: D000818:Animals; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D008168:Lung / Q000276:immunology / Q000473:pathology; D018655:Lymphocyte Count; D008253:Macaca mulatta; D008297:Male; D011020:Pneumonia, Pneumocystis / Q000150:complications / Q000276:immunology* / Q000473:pathology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000150:complications / Q000276:immunology* / Q000473:pathology; D015302:Simian Immunodeficiency Virus; D013601:T-Lymphocytes / Q000276:immunology*