ToxSci Advance Access originally published online on February 18, 2003
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Toxicological Sciences 72, 92-102 (2003)
Copyright © 2003 by the Society of Toxicology
IMMUNOTOXICOLOGY |
Role of Residual Additives in the Cytotoxicity and Cytokine Release Caused by Polyvinyl Chloride Particles in Pulmonary Cell Cultures

* Laboratory of Pneumology (Lung Toxicology), K. U. Leuven, Herestraat 49, B-3000 Leuven, Belgium; and
MRC Toxicology Unit, Lancaster Road, LE1 9HN, Leicester, United Kingdom
Occupational exposure to polyvinyl chloride (PVC) dust has been linked to pulmonary disease. The aim of the present study was to investigate, in vitro, the role of additives in the cytotoxicity and the release of inflammatory mediators caused by PVC particles in different cells. We compared two types of emulsion PVC particles (E3 and E8) with their washed (hence, "additive-free") counterparts (W3 and W8). A positive control (crystalline SiO2, Min-U-Sil) and the pure additives, sodium lauryl sulfate (A3) and sodium alkylbenzenesulfonate (A8), were tested concurrently. Cytotoxicity (MTT assay) was assessed in primary cultures of rat alveolar macrophages, rat type II pneumocytes, and human alveolar macrophages (h-AM), and cultures of the A549 cell line (type II cell-derived) and the differentiated THP-1 cell line (macrophage-like). Hemolytic potential was assessed after a 2-h incubation with human erythrocytes. Cytokine release (IL-8, IL-6, and TNF-
) by A549 cells, THP-1 cells, and h-AM, was measured by ELISA after 4, 16, 24 and/or 48 h of exposure. Cytotoxicity and hemolytic activity of the washed particles were abolished or markedly decreased compared with their nonwashed forms. In A549 cells, E3 and E8 (2.5 mg/ml) caused a 3-fold increase in IL-8 release and a more than 10-fold increase in IL-6 release, whereas W3 and W8 did not elicit any significant response at similar concentrations. Compared with Min-U-Sil (0.1, 0.5, and 2.5 mg/ml), the response to E3 and E8 occurred later and was slightly lower (IL-8) or much more pronounced (IL-6). A3 and A8 exhibited similar responses to E3 and E8, at concentrations corresponding to those present in the particles. In conclusion, thein vitro cytotoxicity and inflammatory potential of some PVC particles appear to be mostly due to their residual additives.
Key Words: polyvinyl chloride; PVC; additive; silica; particle; cytotoxicity; IL-8; IL-6; TNF-
; A549; THP-1.