Immunomodulatory properties of Tamm-Horsfall glycoprotein (THP) and uromodulin.

BACKGROUND Tamm-Horsfall glycoprotein (THP) and uromodulin are the most abundant glycoproteins in non-pregnant women's/men's and pregnant women's urine, respectively. However, the bioactivities of these glycoproteins are still unclear. OBJECTIVE To evaluate the immunomodulatory properties of THP and uromodulin on human peripheral blood mononuclear cells (PBMC) METHODS: THP and uromodulin isolated with diatomaceous earth filtration were subjected to several bioassays, such as MTS viability assay, immunophenotyping and cytokine analysis. RESULTS MTS viability assay and immunophenotyping analysis showed that uromodulin has greater inhibitory activities in suppressing PBMC viability and the percentage of CD4⁺ T helper cells and CD8⁺ cytotoxic T cells, compared to that of THP. In cytokine analysis, THP tended to induce pro-inflammatory cytokines such as IL-1β, TNF and Th1 cytokine IFN-γ; while uromodulin only induced IL-1β and suppressed both Th1 cytokine IFN-γ and Th2 cytokine IL-10. CONCLUSION These results demonstrate that uromodulin has greater immunosuppressive activities and lower inductive property in relation to activation of immune cells, which provides a more tolerant environment for the developing fetus.