Lewis antigen expression on human monocytes and binding of pyrogenic toxins

Toxigenic bacteria such as Bordetella pertussis and Staphylococcus aureus have been implicated in some cases of sudden infant death syndrome (SIDS). We have previously demonstrated that the Lewis(a) antigen is an epithelial cell receptor for S. aureus, and this study demonstrated that Lewis(a) on human monocytes is also a receptor for staphylococcal enterotoxin B (SEB). Values obtained in assays for production of TNF-alpha and nitric oxide were greater for monocytes treated with SEB compared with those treated with lipopolysaccharide (LPS). Exposure to LPS increased the expression of Lewis(a) on monocytes. These results are discussed with reference to the reported enhancement of endotoxic shock by pyrogenic toxins.