Surfactant protein a promotes attachment of Mycobacterium tuberculosis to alveolar macrophages during infection with human immunodeficiency virus.
The incidence of tuberculosis is increasing on a global scale, in part due to its strong association with human immunodeficiency virus (HIV) infection. Attachment of Mycobacterium tuberculosis to its host cell, the alveolar macrophage (AM), is an important early step in the pathogenesis of infection. Bronchoalveolar lavage of HIV-infected individuals demonstrated the presence of a factor which significantly enhances the attachment of tubercle bacilli to AMs 3-fold relative to a normal control population. This factor is surfactant protein A (SP-A). SP-A levels are increased in the lungs of HIV-infected individuals. SP-A levels and attachment of M. tuberculosis to AMs inversely correlate with peripheral blood CD4 lymphocyte counts. Elevated concentrations of SP-A during the progression of HIV infection may represent an important nonimmune risk factor for acquiring tuberculosis, even before significant depletion of CD4 lymphocytes in the peripheral blood occurs.
Downing
J F
JF
Division of Pulmonary and Critical Care Medicine, Indiana University Medical Center, Indianapolis 46202, USA.
Pasula
R
R
Wright
J R
JR
Twigg
H L
HL
Martin
W J
WJ
D017088:AIDS-Related Opportunistic Infections / Q000503:physiopathology; D000818:Animals; D001422:Bacterial Adhesion; D001992:Bronchoalveolar Lavage Fluid; D006023:Glycoproteins / Q000502:physiology; D006678:HIV / Q000502:physiology*; D006801:Humans; D016676:Macrophages, Alveolar / Q000382:microbiology / Q000502:physiology* / Q000821:virology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009169:Mycobacterium tuberculosis / Q000502:physiology*; D011510:Proteolipids / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000032:analysis / Q000096:biosynthesis / Q000502:physiology*; D012016:Reference Values; D014376:Tuberculosis / Q000503:physiopathology
D006023:Glycoproteins; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants