Identification of the lysosomal membrane glycoprotein Lamp-1 as a receptor for type-1-fimbriated (mannose-specific) Escherichia coli.

The presence of several glycosylated sites with high-mannose oligosaccharides on the lysosome-associated membrane glycoproteins (Lamps)_ combined with the fact that neutrophil Lamps are present in mobilizable organelles inspired us to investigate their ability to bind type-1 fimbriated (mannose-binding) Escherichia coli and subsequently define a potential function for the Lamps in human neutrophils. Bacterial binding to Lamps purified from chronic myeloic leukemia cells was investigated by separation of the proteins by sodium dodecyl sulfate polyacrylamide gel electrophoresis, transfer to a blotting membrane and overlay with type-1-fimbriated bacteria. The overlays were developed by growth. The bacteria bound readily to Lamp-1 while there was almost no binding to Lamp-2. Hence, we state that a possible function for neutrophil Lamp-1 is bacterial binding.