Ability of uropathogens to bind to tamm horsfall protein-coated renal tubular cells

Epithelial cells were isolated from a healthy human kidney and found to be of normal, renal tubular origin. The cells were maintained in tissue culture and found to secrete Tamm Horsfall protein (THP). Three strains of uropathogenic Escherichia coli, and one each of Proteus mirabilis and Pseudomonas aeruginosa were found to adhere to the THP-coated tubular cells. Extraneous THP bound to all the organisms except P fimbriated E. coli, and caused a reduction in the adhesion of type 1 fimbriated E. coli and P. mirabilis to the renal cells. However, irrespective of reduced adhesion in three of five strains tested, there was adequate evidence to indicate that THP does not competitively exclude all uropathogenic adhesion. On the contrary, its presence on renal cells may act to mediate bacterial colonization.