TLR- and CXCR1-dependent innate immunity: insights into the genetics of urinary tract infections.

Summary, in English

The susceptibility to urinary tract infection (UTI) is controlled by the innate immune response and Toll like receptors (TLRs) are the sentinels of this response. If productive, TLR4 signalling may initiate the symptomatic disease process. In the absence of TLR4 signalling the infected host instead develops an asymptomatic carrier state. The activation of mucosal TLR4 is also influenced by the properties of the infecting strain, and pathogens use their virulence factors to trigger 'pathogen-specific' TLR4 responses in the urinary tract but do not respond to the asymptomatic carrier strains in patients with asymptomatic bacteriuria (ABU). The TLR4 dependence has been demonstrated in mice and the relevance of low TLR4 function for protection for human disease was recently confirmed in children with asymptomatic bacteriuria, who expressed less TLR4 than age matched controls. Functional chemokines and functional chemokine receptors are crucial for neutrophil recruitment, and for the neutrophil dependent bacterial clearance. Interleukin (IL)-8 receptor deficient mice develop acute septic infections and chronic tissue damage, due to aberrant neutrophil function. This mechanism is relevant for human UTI as pyelonephritis prone children express low levels of the human CXCL8 (Il-8) receptor, CXC chemokine receptor 1 (CXCR1) and often have heterozygous CXCR1 polymorphisms. This review illustrates how intimately the innate response and the susceptibility to UTI are linked and sophisticated recognition mechanisms that rely on microbial virulence and on host TLR4 and CXCR1 signalling.

• Author: Bryndis Ragnarsdottir; Hans Fischer; Gabriela Godaly; Jenny Grönberg Hernandez; Mattias Gustafsson; Diana Karpman; Ann-Charlotte Lundstedt; Nataliya Lutay; S Rämisch; M L Svensson; Björn Wullt; Manisha Yadav; Catharina Svanborg
• Department/s: Division of Microbiology, Immunology and Glycobiology - MIG; Urology; Obstetrics and Gynaecology (Lund); Division of Medical Microbiology; Paediatrics (Lund); Pediatric Nephrology
• Publishing year: 2008
• Language: English
• Pages: 12-20
• Publication/Series: European Journal of Clinical Investigation
• Volume: 38 Suppl 2
• Links: http://www.ncbi.nlm.nih.gov/pubmed/18826477?dopt=Abstract; http://dx.doi.org/10.1111/j.1365-2362.2008.02004.x
• Document type: Journal article review
• Publisher: Wiley-Blackwell
• Topic: Microbiology in the medical area; Immunology in the medical area; Pediatrics; Obstetrics, Gynecology and Reproductive Medicine; Urology and Nephrology
• Status: Published
• Research group: Urology; Pediatric Nephrology
• ISBN/ISSN/Other: ISSN: 0014-2972