Abstract
Toll-like receptor 4 (TLR4) mediates lipopolysaccharide (LPS) signaling in a variety of cell types. MD-2 is associated with the extracellular domain of TLR4 and augments TLR4-dependent LPS responses in vitro. We show here that MD-2−/− mice do not respond to LPS, do survive endotoxic shock but are susceptible to Salmonella typhimurium infection. We found that in MD-2−/− embryonic fibroblasts, TLR4 was not able to reach the plasma membrane and predominantly resided in the Golgi apparatus, whereas TLR4 was distributed at the leading edge surface of cells in wild-type embryonic fibroblasts. Thus, MD-2 is essential for correct intracellular distribution and LPS-recognition of TLR4.
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References
Janeway, C.A. Jr. & Medzhitov, R. Innate immune recognition. Annu. Rev. Immunol. 20, 197–216 (2002).
Aderem, A. & Ulevitch, R.J. Toll-like receptors in the induction of the innate immune response. Nature 406, 782–787 (2000).
Fearon, D.T. & Locksley, R.M. The instructive role of innate immunity in the acquired immune response. Science 272, 50–53 (1996).
Ulevitch, R.J. & Tobias, P.S. Receptor-dependent mechanisms of cell stimulation by bacterial endotoxin. Annu. Rev. Immunol. 13, 437–457 (1995).
Pugin, J. et al. CD14 is a pattern recognition receptor. Immunity 1, 509–516 (1994).
Haziot, A., Lin, X.Y., Zhang, F. & Goyert, S.M. The induction of acute phase proteins by lipopolysaccharide uses a novel pathway that is CD14-independent. J. Immunol. 160, 2570–2572 (1998).
Medzhitov, R., Preston-Hurlburt, P. & Janeway, C.A. Jr. A human homologue of the Drosophila Toll protein signals activation of adaptive immunity. Nature 388, 394–397 (1997).
Rock, F.L., Hardiman, G., Timans, J.C., Kastelein, R.A. & Bazan, J.F. A family of human receptors structurally related to Drosophila Toll. Proc. Natl. Acad. Sci. USA 95, 588–593 (1998).
Poltorak, A. et al. Defective LPS signaling in C3H/HeJ and C57BL/10ScCr mice: mutations in Tlr4 gene. Science 282, 2085–2088 (1998).
Qureshi, S.T. et al. Endotoxin-tolerant mice have mutations in Toll-like receptor 4 (Tlr4). J. Exp. Med. 189, 615–625 (1999).
Hoshino, K. et al. Cutting edge: Toll-like receptor 4 (TLR4)-deficient mice are hyporesponsive to lipopolysaccharide: evidence for TLR4 as the LPS gene product. J. Immunol. 162, 3749–3752 (1999).
Miyake, K., Yamashita, Y., Hitoshi, Y., Takatsu, K. & Kimoto, M. Murine B cell proliferation and protection from apoptosis with an antibody against a 105-kD molecule: unresponsiveness of X-linked immunodeficient B cells. J. Exp. Med. 180, 1217–1224 (1994).
Chan, V.W.F. et al. The molecular mechanism of B cell activation by Toll-like receptor protein RP-105. J. Exp. Med. 188, 93–101 (1998).
Miura, Y. et al. RP105 is associated with MD-1 and transmits an activation signal in human B cells. Blood 92, 2815–2822 (1998).
Miyake, K., Yamashita, Y., Ogata, M., Sudo, T. & Kimoto, M. RP105, a novel B cell surface molecule implicated in B cell activation, is a member of the leucine-rich repeat protein family. J. Immunol. 154, 3333–3340 (1995).
Miyake, K. et al. Mouse MD-1, a molecule that is physically associated with RP105 and positively regulates its expression. J. Immunol. 161, 1348–1353 (1998).
Nagai, Y. et al. Requirement for MD-1 in cell surface expression of RP105/CD180 and B-cell responsiveness to lipopolysaccharide. Blood 99, 1699–1705 (2002).
Shimazu, R. et al. MD-2, a molecule that confers lipopolysaccharide responsiveness on Toll-like receptor 4 J. Exp. Med. 189, 1777–1782 (1999).
da Silva Correia, J. & Ulevitch, R.J. MD-2 and TLR4 N-linked glycosylations are important for a functional lipopolysaccharide receptor. J. Biol. Chem. 277, 1845–1854 (2002).
Ohnishi, T., Muroi, M. & Tanamoto, K.-I. N-Linked glycosylations at Asn26 and Asn114 of human MD-2 Are required for Toll-like receptor 4-mediated activation of NF-κB by lipopolysaccharide. J. Immunol. 167, 3354–3359 (2001).
Schromm, A.B. et al. Molecular genetic analysis of an endotoxin nonresponder mutant cell line: a point mutation in a conserved region of MD-2 abolishes endotoxin-induced signaling. J. Exp. Med. 194, 79–88 (2001).
Visintin, A., Mazzoni, A., Spitzer, J.A. & Segal, D.M. Secreted MD-2 is a large polymeric protein that efficiently confers lipopolysaccharide sensitivity to Toll-like receptor 4. Proc. Natl. Acad. Sci. USA 98, 12156–12161 (2001).
Yang, H., Young, D.W., Gusovsky, F. & Chow, J.C. Cellular events mediated by lipopolysaccharide-stimulated toll-like receptor 4. MD-2 is required for activation of mitogen-activated protein kinases and Elk-1. J. Biol. Chem. 275, 20861–20866 (2000).
Viriyakosol, S., Tobias, P.S., Kitchens, R.L. & Kirkland, T.N. MD-2 binds to bacterial lipopolysaccharide. J. Biol. Chem. 276, 38044–38051 (2001).
Akashi, S. et al. Cutting edge: Cell surface expression and lipopolysaccharide signaling via the Toll-like receptor 4-MD-2 complex on mouse peritoneal macrophages. J. Immunol. 164, 3471–3475 (2000).
Kato, K., Morrison, A.M., Nakano, T., Tashiro, K. & Honjo, T. ESOP-1, a secreted protein expressed in the hematopoietic, nervous, and reproductive systems of embryonic and adult mice. Blood 96, 362–364 (2000).
Takeuchi, O. et al. Differential roles of TLR2 and TLR4 in recognition of gram-negative and gram-positive bacterial cell wall components. Immunity 11, 443–451 (1999).
Bernheiden, M. et al. LBP, CD14, TLR4 and the murine innate immune response to a peritoneal Salmonella infection. J. Endotoxin Res. 7, 447–450 (2001).
Thieblemont, N. & Wright, S.D. Transport of bacterial lipopolysaccharide to the Golgi apparatus. J. Exp. Med. 190, 523–534 (1999).
Cole, L., Davies, D., Hyde, G.J. & Ashford, A.E. ER-Tracker dye and BODIPY-brefeldin A differentiate the endoplasmic reticulum and Golgi bodies from the tubular-vacuole system in living hyphae of Pisolithus tinctorius. J. Microsc. 197, 239–249 (2000).
Randow, F. & Seed, B. Endoplasmic reticulum chaperone gp96 is required for innate immunity but not cell viability. Nature Cell Biol. 3, 891–896 (2001).
Hornef, M.W., Frisan, T., Vandewalle, A., Normark, S. & Richter-Dahlfors, A. Receptor 4 resides in the Golgi apparatus and colocalizes with internalized lipopolysaccharide in intestinal epithelial cells. J. Exp. Med. 195, 559–570 (2002).
Underhill, D.M. et al. The Toll-like receptor 2 is recruited to macrophage phagosomes and discriminates between pathogens. Nature 401, 811–815 (1999).
Kawasaki, K. et al. Mouse Toll-like receptor 4.MD-2 complex mediates lipopolysaccharide-mimetic signal transduction by taxol. J. Biol. Chem. 275, 2251–2254 (2000).
Kawasaki, K., Gomi, K. & Nishijima, M. Cutting edge: Gln22 of mouse MD-2 is essential for species-specific lipopolysaccharide mimetic action of Taxol. J. Immunol. 166, 11–14 (2001).
Akashi, S. et al. Human MD-2 confers on mouse Toll-like receptor 4 species-specific lipopolysaccharide recognition. Int. Immunol. 13, 1595–1599 (2001).
Poltorak, A., Ricciardi-Castagnoli, P., Citterio, S. & Beutler, B. Physical contact between lipopolysaccharide and toll-like receptor 4 revealed by genetic complementation. Proc. Natl. Acad. Sci. USA 97, 2163–2167 (2000).
Lien, E. et al. Toll-like receptor 4 imparts ligand-specific recognition of bacterial lipopolysaccharide. J. Clin. Invest. 105, 497–504 (2000).
Hajjar, A.M., Ernst, R.K., Tsai, J.H., Wilson, C.B. & Miller, S.I. Toll-like receptor 4 recognizes host-specific LPS modifications. Nature Immunol. 3, 354–359 (2002).
Yagi, T. et al. A novel negative selection for homologous recombinants using diphtheria toxin A fragment gene. Ann. Biochem. 214, 77–86 (1993).
Niwa, H., Miyazaki, J. & Smith, A.G. Quantitative expression of Oct-3/4 defines differentiation, dedifferentiation or self-renewal of ES cells. Nature Genet. 24, 372–376 (2000).
Ogata, H. et al. The Toll-like receptor protein RP105 regulates lipopolysaccharide signaling in B cells. J. Exp. Med. 192, 23–30 (2000).
Inaba, K. et al. Generation of large numbers of dendritic cells from mouse bone marrow cultures supplemented with granulocyte/macrophage colony-stimulating factor. J. Exp. Med. 176, 1693–1702 (1992).
Morita, S., Kojima, T. & Kitamura, T. Plat-E: an efficient and stable system for transient packaging of retroviruses. Gene Ther. 7, 1063–1066 (2000).
Acknowledgements
We thank R. Horai, K. Fukudome and T. Furuta for technical suggestions; and P. W. Kincade and D. R. Liddicoat for helpful comments on the manuscript. Supported by Special Coordination Funds of the Ministry of Education, Culture, Sports, Science and Technology of the Japanese Government (Monbukagakusho); the Uehara Memorial Foundation; the Yamanouchi Foundation for Research on Metabolic Disorders; Mitsubishi Pharma; and Sankyo.
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Nagai, Y., Akashi, S., Nagafuku, M. et al. Essential role of MD-2 in LPS responsiveness and TLR4 distribution. Nat Immunol 3, 667–672 (2002). https://doi.org/10.1038/ni809
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DOI: https://doi.org/10.1038/ni809