Immunomodulatory oligonucleotides inhibit neutrophil migration by decreasing the surface expression of interleukin-8 and leukotriene B4 receptors

Neutrophils play important roles in many inflammatory diseases. The migration of neutrophils to the inflammatory site is tightly regulated by specific chemokines, of which interleukin-8 (IL-8) and leukotriene B4 (LTB4 ) constitute key mediators by binding to the surface receptors CXCR1/2 and BLT1, respectively. Oligonucleotides (ODN) containing CpG motifs mediate potent immunomodulatory effects through binding to Toll-like receptor 9. So far, knowledge on how ODN can affect neutrophil migration during inflammation is lacking. This study demonstrates that several novel CpG ODN significantly down-regulate the surface expression of CXCR1/2 and BLT1. In addition, the ODN significantly blocked IL-8-induced and LTB4 -induced neutrophil migration in vitro, as well as leucocyte migration in vivo demonstrated in mice by intravital microscopy and in a model of airway inflammation. The down-regulation of CXCR1 is rapid, occurring 15 min after ODN stimulation, and can be mediated through an endosomally independent mechanism. Inhibition of the IL-8 and LTB4 pathways may provide new opportunities of therapeutic intervention using ODN to reduce neutrophil infiltration during inflammation.

Identification of a new WASP and FKBP-like (WAFL) protein in inflammatory bowel disease: a potential marker gene for ulcerative colitis

BACKGROUND AND AIMS

Inflammatory bowel disease (IBD) is a complex inflammatory disease of the gastrointestinal tract with unknown cause that lacks molecular markers for diagnosis. Crohn's disease (CD) and ulcerative colitis (UC) are the two major forms of IBD. The aim of this study was to investigate gene expression patterns in UC and characterize newly identified marker genes potentially linked to disease pathogenesis of UC.

MATERIALS AND METHODS

Biopsies were taken from eight UC patients, from inflamed and non-inflamed parts of the colon. Gene expression was investigated by subtractive suppression hybridization (SSH), and further study of a selected gene was performed by Northern blot, immunohistochemistry, immunocytochemistry, and in vitro monocyte differentiation.

RESULTS

Three hundred thirty-one differentially expressed genes were found and classified into functional groups. In this paper, we report one gene with unknown function to be differentially expressed in UC but not Crohn's disease by real-time reverse transcriptase polymerase chain reaction. Due to its predicted protein architecture, we call this gene Wiskott-Aldrich syndrome protein and FKBP-like (WAFL). Initial pilot experiments suggest WAFL to participate in innate immune functions.

CONCLUSION

The SSH result supports the current view of UC to be a chronic inflammatory disorder with aberrant expression of epithelial barrier proteins, cell fate-related factors, and disturbed metabolism. The new gene, WAFL, reported in this study, appears to be conditionally regulated in myeloid cells. This indicates that WAFL may be connected to innate immune-host responses. As such, it represents an interesting, hitherto unknown player in IBD where there is a need for further elucidation on the molecular and cellular level.