Affiliation:
1. *Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814;
2. †Department of Cell Biology and Immunology, Free University, Amsterdam, The Netherlands;
3. ‡Department of Immunology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
Abstract
AbstractThe host response to Gram-negative LPS is characterized by an influx of inflammatory cells into host tissues, which is mediated, in part, by localized production of chemokines. The expression and function of chemokines in vivo appears to be highly selective, though the molecular mechanisms responsible are not well understood. All CXC (IFN-γ-inducible protein (IP-10), macrophage inflammatory protein (MIP)-2, and KC) and CC (JE/monocyte chemoattractant protein (MCP)-1, MCP-5, MIP-1α, MIP-1β, and RANTES) chemokine genes evaluated were sensitive to stimulation by LPS in vitro and in vivo. While IL-10 suppressed the expression of all LPS-induced chemokine genes evaluated in vitro, treatment with IFN-γ selectively induced IP-10 and MCP-5 mRNAs, but inhibited LPS-induced MIP-2, KC, JE/MCP-1, MIP-1α, and MIP-1β mRNA and/or protein. Like the response to IFN-γ, LPS-mediated induction of IP-10 and MCP-5 was Stat1 dependent. Interestingly, only the IFN-γ-mediated suppression of LPS-induced KC gene expression was IFN regulatory factor-2 dependent. Treatment of mice with LPS in vivo also induced high levels of chemokine mRNA in the liver and lung, with a concomitant increase in circulating protein. Hepatic expression of MIP-1α, MIP-1β, RANTES, and MCP-5 mRNAs were dramatically reduced in Kupffer cell-depleted mice, while IP-10, KC, MIP-2, and MCP-1 were unaffected or enhanced. These findings indicate that selective regulation of chemokine expression in vivo may result from differential response of macrophages to pro- and antiinflammatory stimuli and to cell type-specific patterns of stimulus sensitivity. Moreover, the data suggest that individual chemokine genes are differentially regulated in response to LPS, suggesting unique roles during the sepsis cascade.
Publisher
The American Association of Immunologists
Subject
Immunology,Immunology and Allergy
Reference69 articles.
1. Bone, R. C.. 1993. Gram-negative sepsis: a dilemma of modern medicine. Clin. Microbiol. Rev. 6: 57
2. Dellinger, R., S. M. Opal, D. Rotrosen, A. F. Suffredini, J. L. Zimmerman. 1997. From the bench to the bedside: the future of sepsis research. Chest 111: 744
3. Manthey, C. L., S. N. Vogel. 1992. The role of cytokines in host response to endotoxin. Rev. Med. Microbiol. 3: 72
4. Morrison, D. C., R. L. Danner, C. A. Dinarello, S. Munford, C. Natanson, M. Pollack, J. J. Spitzer, R. J. Ulevitch, S. N. Vogel, E. McSweegan. 1994. Bacterial endotoxins and pathogenesis of Gram-negative infections: current status and future direction. J. Endotoxin Res. 1: 71
5. Evans, G. F., Y. M. Snyder, L. D. Butler, S. H. Zuckerman. 1989. Differential expression of interleukin-1 and tumor necrosis factor in murine septic shock models. Circ. Shock 29: 279