Mannhardt W, Becker A, Putzer M, Bork M, Zepp F, Hacker J, Schulte-Wissermann H
Department of Pediatrics, University of Mainz, Germany.
Pediatr Nephrol. 1996 Oct;10(5):568-72. doi: 10.1007/s004670050162.
Uroepithelial defense has ben suggested to contribute to the local host resistance against ascending urinary tract infection. The cellular mechanism, however, is not known. In this study, bacterial growth was measured under the direct and indirect influence of uroepithelial cells. To study if a specific ligand-receptor interaction is required for uroepithelial cell (UEC) activation, isogenic Escherichia coli mutants expressing either mannose-sensitive, mannose-resistant (p), or mannose resistant (s) pili were tested for their capacity to induce the UEC defense mechanism. The antibacterial effect of UEC was abolished either by performing coculture in chambers with a fluid-permeable membrane which separates UEC from bacteria or by inhibiting membrane contact using the antiadherence factor pentosane polysulfate. No difference between the various types of pili could be shown. All E. coli strains adhered comparably to the UEC and were subsequently suppressed in their growth. Even a "naked" mutant without expression of common pili showed a similar behavior. In conclusion, bacterial growth suppression depends on direct contact between the UEC and bacteria, but is independent of common pili expressed on E. coli.
尿路上皮防御被认为有助于局部宿主抵抗上行性尿路感染。然而，其细胞机制尚不清楚。在本研究中，在尿路上皮细胞的直接和间接影响下测量细菌生长。为了研究尿路上皮细胞（UEC）激活是否需要特定的配体-受体相互作用，测试了表达甘露糖敏感、甘露糖抗性（p）或甘露糖抗性（s）菌毛的同基因大肠杆菌突变体诱导UEC防御机制的能力。通过在具有可渗透流体的膜的小室中进行共培养（该膜将UEC与细菌分开）或使用抗粘附因子戊聚糖多硫酸盐抑制膜接触，可消除UEC的抗菌作用。各种类型的菌毛之间未显示出差异。所有大肠杆菌菌株与UEC的粘附程度相当，随后其生长受到抑制。即使是不表达普通菌毛的“裸”突变体也表现出类似的行为。总之，细菌生长抑制取决于UEC与细菌之间的直接接触，但与大肠杆菌上表达的普通菌毛无关。
