title: Effect of simian immunodeficiency virus infection on tumor necrosis factor-alpha production by alveolar macrophages.
abstract: We studied the release of tumor necrosis factor-alpha (TNF alpha), a vital immunoregulatory cytokine, by alveolar macrophages (M phi s) infected with simian immunodeficiency virus (SIV) in vitro or collected from SIV-infected macaques. For in vitro studies, M phi s were harvested by bronchoalveolar lavage from 5 normal animals and infected in flasks with SIV (10(4)TCID50/2.5 x 10(6) M phi s). After 7 to 10 days, cytopathic effect was prominent and 68 +/- 2% of M phi s were immunoreactive for p27 core protein. Uninfected (control) and SIV-infected M phi s were then cultured for 24 hours in 96-well plates (10(5) M phi s/well) while challenged with lipopolysaccharide (LPS; 100 micrograms/ml). TNF alpha was assayed in culture supernatants by an enzyme-linked immunosorbent assay (detection limit, 50 pg/ml) and results were expressed as pg TNF alpha/ml/10(3) M phi s (mean +/- SEM). TNF alpha was not detected in unstimulated wells. TNF alpha release by control and SIV-infected M phi s was similar (6.6 +/- 0.7 and 7.9 +/- 1.1 pg/ml/10(3) M phi s, respectively). We also studied TNF alpha release by alveolar M phi s from 8 animals infected with SIV (3 asymptomatic, 5 with acquired immune deficiency syndrome virus (AIDS]. One animal with AIDS had p27+ M phi s. Alveolar M phi s from asymptomatic animals released significantly more TNF alpha (10.3 +/- 1.1 pg/ml/10(3) M phi s) than did animals with AIDS or uninfected macaques (5.2 +/- 0.8 and 7.0 +/- 0.6 pg/ml/10(3) M phi s, respectively) (p less than 0.01). However, M phi s from monkeys with AIDS failed to respond to LPS after 7 to 10 days in culture. In summary, in vitro infection with SIV does not cause constitutive TNF alpha release or alter the response of cultured M phi s to LPS. When kept in culture, M phi s collected from asymptomatic, SIV-infected animals retain their response to LPS, whereas M phi s from animals with AIDS lose the capacity to produce TNF alpha. Furthermore, M phi s cytokine production is exaggerated before overt clinical disease, but not as a direct result of infection with SIV.
authors.affiliation: New England Regional Primate Research Center, Harvard Medical School, Southborough, Massachusetts.
authors.forename: C J
authors.initials: CJ
authors.lastname: Horvath
authors.forename: R C
authors.initials: RC
authors.lastname: Desrosiers
authors.forename: P K
authors.initials: PK
authors.lastname: Sehgal
authors.forename: N W
authors.initials: NW
authors.lastname: King
authors.forename: D J
authors.initials: DJ
authors.lastname: Ringler
mesh_terms: D000818:Animals; D002452:Cell Count; D004797:Enzyme-Linked Immunosorbent Assay; D008251:Macaca; D008264:Macrophages / Q000378:metabolism* / Q000473:pathology; D011650:Pulmonary Alveoli / Q000378:metabolism* / Q000473:pathology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis*
chemical_list: D014409:Tumor Necrosis Factor-alpha