TAMM-HORSFALL PROTEIN ISOLATED FROM URINE OF PREGNANT AND NONPREGNANTWOMEN HAS SIMILAR OLIGOSACCHARIDES

Background Differences in the immunosuppressive activity of Tamm-Horsf all protein and uromodulin claimed by many investigators are controver sial. They have been ascribed to variations in the carbohydrate moiety . Methods We isolated urinary glycoproteins from 18 non-pregnant (THP) and 12 pregnant (UM) women using the same method (adsorption on diato maceous earth) and performed comparative studies including monocarbohy drate analysis and tests of reactivity with lectins, cytokines and ser um proteins. Results No significant differences in monocarbohydrate co ntent or in the reactivity with specific lectins were found between th e native urinary glycoproteins or between their proteolytic products. Also, in Sda+ and Sda- donors monitored throughout pregnancy and after delivery, no time-dependent differences in the sugar moiety were obse rved. We found that THP/UM from Sda+ donors reacted more strongly with PHA-L than THP/UM from Sda- donors, providing further evidence for ca rbohydrate variations between Sda+ and Sda- determinants. No differenc es between THP and UM in terms of their reactivity with recombitant hu man interleukin (rhIL) 1 alpha, recombinant human tumour necrosis fact or (rhTNF) alpha and some serum proteins were found, indicating simila r biological activity. Conclusion The results of our carbohydrate anal ysis together with previous data on amino acid analysis indicate that Tamm-Horsfall protein and uromodulin are identical or very similar gly coproteins.