Surfactant prevents quartz induced down-regulation of complement receptor 1 in human granulocytes

• Published in: Inflammation Vol. 21; no. 1; pp. 83 - 92
• Main Authors: Zetterberg, G, Lundahl, J, Curstedt, T, Eklund, A
• Format: Journal Article
• Language: English
• Published: United States 01.02.1997
• Subjects: Adolescent; Adult; Aged; Animals; Down-Regulation - drug effects; Granulocytes - drug effects; Granulocytes - metabolism; Humans; Lipids - chemical synthesis; Lipids - pharmacology; Medicin och hälsovetenskap; Middle Aged; Pulmonary Surfactants - pharmacology; Quartz - toxicity; Receptors, Complement - antagonists & inhibitors; Receptors, Complement - biosynthesis; Receptors, Complement - drug effects; Swine
• ISSN: 0360-3997
• DOI: 10.1023/A:1027394926261

Quartz is known to induce an inflammatory response in the alveolar space by recruitment of different effector cells. We investigated the interaction between granulocytes and quartz with respect to expression of complement receptor type 1 (CR1) and CR3, with and without the presence of surfactant. Granulocytes from hemolyzed blood were stimulated by N-formyl-methionyl-leucyl-phenylalanine (fMLP), which mobilize the intracellular pool of CR1 to the surface, and the mean fluorescence intensity (MFI) measured by cytofluorometry was 47.4 (46-63.6) (median; interquartile range). Quartz exposure reduced the CR1 expression to 23.2 (22.8-30.6) MFI units (P < 0.01), a porcine surfactant preparation added during quartz exposure abolished the down-regulation completely, 47.7 (43.2-62.3) MFI units (P < 0.001). Similar results were obtained after preincubation of the cells with surfactant followed by quartz exposure. No significant influence on CR1 expression was found by a synthetic lipid mixture, nor was the CR3 expression affected. In conclusion, this study demonstrates that the presence of surfactant inhibits quartz induced down-regulation of CR1 on activated granulocytes.