interleukin-8 and Angiomatosis--Bacillary

The gram-negative bacterium Bartonella henselae is capable of causing angiogenic lesions as a result of infection. Previously, it has been shown that B. henselae infection can result in production of the chemokine interleukin-8 (IL-8). In this study, we demonstrated that monocytes, endothelial cells, and hepatocytes produce IL-8 in response to B. henselae infection. We also investigated the role of IL-8 in B. henselae-induced endothelial cell proliferation and capillary tube formation. Both in vitro angiogenesis assays were IL-8 dependent. B. henselae-mediated inhibition of apoptosis, as indicated by gene expression of Bax and Bcl-2, was also shown to be IL-8 dependent in endothelial cells. Furthermore, infection of endothelial cells with B. henselae stimulated upregulation of the IL-8 chemokine receptor CXCR2. Infection of human endothelial cells by B. henselae resulting in IL-8 production likely plays a central role in the ability of this organism to cause angiogenesis during infection.

Topics: Angiomatosis, Bacillary; Apoptosis; Autocrine Communication; Bartonella henselae; bcl-2-Associated X Protein; Capillaries; Cell Proliferation; Cells, Cultured; Endothelium, Vascular; Gene Expression; Hepatocytes; Humans; Immunoglobulin G; Interleukin-8; Monocytes; Neovascularization, Pathologic; Proto-Oncogene Proteins c-bcl-2; Receptors, Interleukin-8B; Up-Regulation