Immunomodulating Properties of Stored Product Mite Extracts on Human Dermal Fibroblasts

Abstract

RATIONALE: Since dust and/or scabies mite extracts are the sources of bioactive components that influence the function of lung epithelial cells, fibroblasts, keratinocytes, skin endothelial cells, lymphocytes, monocytes, and dendritic cells, we undertook a study to determined if components in storage mite extracts influenced the function of fibroblasts that are a common cell type in many tissues. METHODS: Normal human dermal fibroblasts were cultured and then exposed to whole body extracts from the stored product mites Acarus siro (AS), Chortoglyphus arcuatus (CA), and Lepidoglyphus destructor (LD) in the presence or absence of lipopolysaccharide (LPS). Cytokine secretion by the cells was measured by ELISA. RESULTS: Components in the body extracts of all three species of mites induced the secretion of IL-8 while CA and LD induced secretion of IL-6 and MCP-1 generally in a dose dependent manner. CA extracts induced greater secretion of IL-6 than did LD while LD and CA induced secretion of greater amounts of IL-8 at lower doses than AS. There was no mite-induced secretion of IL-1ra, IL-1α, IL-1β, IL-7, IL-15, MIP-1α, M-CSF, TNFα, or eotaxin. CA body and fecal extracts were fractionated by isoelectric focusing (pH 2.0-12.0). Fractions of pI 5.8-6.3 of the CA body extract induced secretion of IL-6 while no fraction of the fecal extract induced IL-6 secretion. CONCLUSIONS: This study demonstrated that components of storage mite extracts influence the secretion of IL-6, IL-8, and MCP-1 by dermal fibroblasts and therefore may influence the course of an inflammatory and immune reaction.