LDL-mediated interaction of DNA and DNA-anti-DNA immune complexes with cell surface.

The effect of low-density lipoprotein (LDL) on the binding of DNA and DNA-anti-DNA immune complexes to cultured human skin fibroblasts was examined. Using radioisotope analysis, ELISA and indirect immunofluorescent staining, a correlation between plasma membrane-bound DNA or DNA-anti-DNA immune complexes and cell-associated LDL was established. It was demonstrated that cytotoxicity and internalization of DNA-anti-DNA immune complexes may be LDL mediated. The data obtained suggest that the binding of the major part of DNA and immune complexes bound to surface of normal skin fibroblasts is due to the formation of a DNA-LDL-LDL receptor linkage. A possible role of LDL-containing immune complexes in the pathogenesis of systemic lupus erythematosus is discussed.