The long polar fimbriae of STEC O157:H7 induce expression of pro-inflammatory markers by intestinal epithelial cells.
Infection with Shiga toxin-producing Escherichia coli (STEC) O157:H7 is characterized by acute inflammation of the colonic mucosa. STEC O157:H7 contains two non-identical loci encoding long polar fimbriae (Lpf), which play a role in the STEC colonization of the intestinal epithelial cells. However, no information is available regarding the involvement of Lpf in the STEC-induced host inflammatory response. Hence, in this study we assess the role of Lpf as an inducer of inflammation on intestinal epithelial cells. Secretion of pro-inflammatory cytokines in response to STEC wild type and lpf isogenic mutants was evaluated on intestinal T84 cells. Of the 27 cytokines assayed, IL-6, IL-8, IL-15, FGF, GM-CSF and IP-10 were significantly reduced, when compared to the wild-type strain, in the lpfA1 lpfA2 double mutant. Further, the host intracellular signaling pathways activated in response to Lpf were determined by using an array containing genes representative of 18 different signal transduction pathways. The analysis indicated that the NF-κB pathway is activated in response to Lpf-expressing STEC. Therefore, our study supports the role of Lpf as a STEC factor mediating intestinal inflammation.
Centro de Estudios Moleculares, Departamento de Pediatría, Facultad de Medicina, Universidad de Chile, Hospital Dr. Luis Calvo Mackenna, Santiago, Chile. mfarfan@med.uchile.cl
Mauricio J
MJ
Farfan
Lidia
L
Cantero
Alejandra
A
Vergara
Roberto
R
Vidal
Alfredo G
AG
Torres
D001422:Bacterial Adhesion / Q000276:immunology; D002460:Cell Line; D016207:Cytokines / Q000032:analysis / Q000276:immunology; D004847:Epithelial Cells / Q000276:immunology / Q000382:microbiology; D004927:Escherichia coli Infections / Q000276:immunology* / Q000382:microbiology; D019453:Escherichia coli O157 / Q000276:immunology*; D010861:Fimbriae, Bacterial / Q000276:immunology*; D020869:Gene Expression Profiling; D006801:Humans; D007249:Inflammation / Q000276:immunology* / Q000382:microbiology; D007410:Intestinal Diseases / Q000276:immunology / Q000382:microbiology*; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000276:immunology
D016207:Cytokines; D012329:RNA, Bacterial