Abstract
Surfactant lipids inhibit cytokine production by immune cells, and surfactant protein A (SP-A) stimulates it. By enzyme-linked immunosorbent assay and mRNA blotting, we studied proinflammatory cytokine production by the monocytic cell line THP-1. SP-A caused increases in tumor necrosis factor (TNF)-α within 1 h, peaking at 4 h and then declining. Interleukin (IL)-1β increased and stayed elevated for 24 h. SP-A stimulated IL-8 also, peaking at 4 h, rapidly declining, and peaking again at 24 h. SP-A-dependent changes were detected for IL-6, but at higher SP-A doses. mRNA levels for TNF-α and IL-1β increased in response to SP-A, peaking within 2 h. The increases in TNF-α mRNA and protein induced by SP-A were inhibited by surfactant lipids. For IL-Iβ and IL-8, the lipids either had no inhibitory influence or inhibited less than for TNF-α. This suggests that the ability of macrophages to participate in inflammatory reactions is enhanced by SP-A alone or by mixtures of lipids and SP-A containing more SP-A than in normal surfactant, as occurs in many conditions leading to inflammation.
Original language | English (US) |
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Pages (from-to) | L996-L1004 |
Journal | American Journal of Physiology - Lung Cellular and Molecular Physiology |
Volume | 272 |
Issue number | 5 16-5 |
DOIs | |
State | Published - May 1997 |
All Science Journal Classification (ASJC) codes
- Physiology
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology