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Crosstalk between autoreactive T cells and alveolar type II epithelial cells in inflammation and tolerance

von Dr. Marcus Gereke

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[1.] Mag/Fragment 021 01 - Diskussion
Zuletzt bearbeitet: 2014-03-10 12:12:09 Graf Isolan
BauernOpfer, Fragment, Gesichtet, Mag, SMWFragment, Schutzlevel sysop, Wright 2005

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Bearbeiter
Hindemith
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Untersuchte Arbeit:
Seite: 21, Zeilen: 1-31
Quelle: Wright 2005
Seite(n): 61, 62, 63, Zeilen: 61: l.col: 17ff; 62: r.col:18ff; 63: r.col: 20ff
Glycoprotein 340 (gp340) is also discussed as a protein that binds SP-D through its CRD (Holmskov et al., 1997). Because of its localisation at the cell surface of alveolar macrophages, gp340 was suggested to be a SP-D receptor. It is identical to salivary agglutinin, a high-molecular-weight component of saliva that binds Streptococcus mutans, a bacterium that causes dental caries (Prakobphol et al., 2000). This putative receptor gp340 has no transmembrane domain so that it is suggested that it could interact with an adaptor molecule on the surface of the cell (Wright, 2005).

Additionally, a family of conserved cellular receptors that recognize pathogen-associated molecular patterns (PAMP) are discussed as binding-partners for SP-A and SP-D. This family of Toll-like receptors (TLRs) is activated by ligands like flagellin and CpG-containing DNA from bacteria, peptidoglycan from Gram-positive bacteria, LPS from Gram-negative bacteria, RNA from viruses and zymosan from yeast (Takeda et al., 2003). All these activation mechanisms end up in a series of conserved responses that culminate in inflammation and the production of inflammatory cytokines, such as TNF and interleukin-1β. The SP-A dependent binding to TLR4 results in an activation of the nuclear factor κB (NF-κB) signalling pathway and upregulation of cytokine synthesis (Guillot et al., 2002), whereas interaction of SP-A with TLR2 attenuates stimulation of TLR2 signalling and also stimulation of TNF secretion induced by zymosan or peptidoglycan (Sato et al., 2003).

In addition to phagocytosis, SP-A and SP-D have also the ability to regulate the production of inflammatory mediators by immune cells in a context-dependent manner. One example shows that inflammatory mediators, such as TNF, are both up- and downregulated by SP-A and SP-D (Crouch and Wright, 2001). The release of TNF that is induced by LPS or intact bacteria is inhibited by SP-A (Hickling et al., 1998; McIntosh et al., 1996; Rosseau et al., 1999). In contrast, SP-A enhances TNF production either when alone (Kremlev et al., 1994, Kremlev et al., 1997) or in presence of “rough” LPS (Sano et al., 1999).

A further effect of surfactant proteins SP-A and SP-D is the enhanced uptake of apoptotic cells by alveolar macrophages in vitro (Schagat, et al., 2001), which could be even shown for lungs of naïve mice in the case of SP-D (Vandivier et al., 2002).


Crouch E, Wright JR. Surfactant proteins a and d and pulmonary host defense. Annu Rev Physiol. 2001; 63: 521-54. Review.

Guillot L, Balloy V, McCormack FX, Golenbock DT, Chignard M, Si-Tahar M. Cutting edge: the immunostimulatory activity of the lung surfactant protein-A involves Toll-like receptor 4. J Immunol. 2002 Jun 15; 168 (12): 5989-92.

Hickling TP, Sim RB, Malhotra R. Induction of TNF-alpha release from human buffy coat cells by Pseudomonas aeruginosa is reduced by lung surfactant protein A. FEBS Lett. 1998 Oct 16; 437 (1-2): 65-9.

Holmskov U, Lawson P, Teisner B, Tornoe I, Willis AC, Morgan C, Koch C, Reid KB. Isolation and characterization of a new member of the scavenger receptor superfamily, glycoprotein-340 (gp-340), as a lung surfactant protein-D binding molecule. J Biol Chem. 1997 May 23; 272 (21): 13743-9.

Kremlev SG, Phelps DS. Surfactant protein A stimulation of inflammatory cytokine and immunoglobulin production. Am J Physiol. 1994 Dec; 267 (6Pt1): L712-9.

Kremlev SG, Umstead TM, Phelps DS. Surfactant protein A regulates cytokine production in the monocytic cell line THP-1. Am J Physiol. 1997 May; 272 (5Pt1): L996-1004.

McIntosh JC, Mervin-Blake S, Conner E, Wright JR. Surfactant protein A protects growing cells and reduces TNF-alpha activity from LPS-stimulated macrophages. Am J Physiol. 1996 Aug; 271 (2Pt1): L310-9.

Prakobphol A, Xu F, Hoang VM, Larsson T, Bergstrom J, Johansson I, Frangsmyr L, Holmskov U, Leffler H, Nilsson C, Boren T, Wright JR, Stromberg N, Fisher SJ. Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340. J Biol Chem. 2000 Dec 22; 275 (51): 39860-6.

Rosseau S, Hammerl P, Maus U, Gunther A, Seeger W, Grimminger F, Lohmeyer J. Surfactant protein A down-regulates proinflammatory cytokine production evoked by Candida albicans in human alveolar macrophages and monocytes. J Immunol. 1999 Oct 15; 163 (8): 4495-502.

Sano H, Sohma H, Muta T, Nomura S, Voelker DR, Kuroki Y. Pulmonary surfactant protein A modulates the cellular response to smooth and rough lipopolysaccharides by interaction with CD14. J Immunol. 1999 Jul 1; 163 (1):387-95.

Schagat TL, Wofford JA, Wright JR. Surfactant protein A enhances alveolar macrophage phagocytosis of apoptotic neutrophils. J Immunol. 2001 Feb 15; 166 (4): 2727-33.

Sato M, Sano H, Iwaki D, Kudo K, Konishi M, Takahashi H, Takahashi T, Imaizumi H, Asai Y, Kuroki Y. Direct binding of Toll-like receptor 2 to zymosan, and zymosan-induced NF-kappa B activation and TNF-alpha secretion are down-regulated by lung collectin surfactant protein A. J Immunol. 2003 Jul 1; 171 (1): 417-25.

Takeda K, Takeuchi O, Akira S. Recognition of lipopeptides by Toll-like receptors. J Endotoxin Res. 2002; 8 (6): 459-63.

Vandivier RW, Ogden CA, Fadok VA, Hoffmann PR, Brown KK, Botto M, Walport MJ, Fisher JH, Henson PM, Greene KE. Role of surfactant proteins A, D, and C1q in the clearance of apoptotic cells in vivo and in vitro: calreticulin and CD91 as a common collectin receptor complex. J Immunol. 2002 Oct 1; 169 (7): 3978-86.

Wright JR. Immunoregulatory functions of surfactant proteins. Nat Rev Immunol. 2005 Jan; 5 (1): 58-68. Review.

Glycoprotein 340 (gp340) was initially identified as a protein that binds the CRD of SP-D49. Because of its location at the cell surface of alveolar macrophages, gp340 was suggested to be an SP-D receptor. It was subsequently shown to be identical to salivary agglutinin, a high-molecular-weight component of saliva that binds Streptococcus mutans, a bacterium that causes dental caries50. gp340 does not have a transmembrane domain, and its identity as an SP-D receptor remains unclear. The possibility that gp340 could interact with an adaptor molecule on the surface of the cell has not yet been investigated.

Other recent studies have reported that SP-A and SP-D bind to Toll-like receptors (TLRs) — a family of conserved cellular receptors that recognize pathogenassociated molecular patterns, including flagellin and CpG-containing DNA from bacteria, peptidoglycan from Gram-positive bacteria, LPS from Gram-negative bacteria, RNA from viruses and zymosan from yeast51. Activation of TLRs by these ligands initiates a conserved series of responses that culminate in inflammation and the production of inflammatory cytokines, such as TNF and interleukin-1β (IL-1β). Guillot and co-workers52 observed a TLR4-dependent SP-A activation of the nuclear factor-κB (NF-κB)-signalling pathway and upregulation of cytokine synthesis in TLR4-transfected Chinese hamster ovary cells. Such a response was lacking in the TLR4-deficient mice. In addition, Murakami and colleagues53 reported that SP-A directly binds TLR2. By contrast, the interaction of SP-A with TLR2 attenuates stimulation of TLR2 signalling and also stimulation of TNF secretion induced by zymosan or peptidoglycan. [...]

[page 62]

Collectins regulate multiple cellular responses in addition to phagocytosis. SP-A and SP-D also regulate the production of inflammatory mediators by immune cells in a context-dependent manner. Several reports show that inflammatory mediators, such as TNF, are both upregulated and downregulated27 by SP-A and SP-D. For example, SP-A inhibits62–64 the release of TNF that is induced by LPS or intact bacteria; by contrast, SP-A enhances TNF production either when alone65,66 or in the presence of ‘rough’LPS67. [...]

[page 63]

Recent studies have shown that both SP-A and SP-D enhance the uptake of apoptotic cells by alveolar macrophages in vitro79. Vandivier and colleagues80 showed that SP-A, SP-D and C1q all enhanced apoptotic-cell uptake by mouse and human alveolar macrophages in vitro, but only SP-D altered apoptotic-cell clearance from naive mouse lung80.


27. Crouch, E. & Wright, J. R. Surfactant proteins A and D and pulmonary host defense. Annu. Rev. Physiol. 63, 521–554 (2001).

49. Holmskov, U. et al. Isolation and characterization of a new member of the scavenger receptor superfamily, glycoprotein-340 (gp-340), as a lung surfactant protein-D binding molecule. J. Biol. Chem. 272, 13743–13749 (1997).

50. Prakobphol, A. et al. Salivary agglutinin, which binds Streptococcus mutans and Helicobacter pylori, is the lung scavenger receptor cysteine-rich protein gp-340. J. Biol. Chem. 275, 39860– 39866 (2000).

51. Takeda, K., Kaisho, T. & Akira, S. Toll-like receptors. Annu. Rev. Immunol. 21, 335–376 (2003).

52. Guillot, L. et al. The immunostimulatory activity of the lung surfactant protein-A involves Toll-like receptor 4. J. Immunol. 168, 5989–5992 (2002).

53. Sato, M. et al. Direct binding of Toll-like receptor 2 to zymosan, and zymosan-induced NF-κB activation and TNF-á secretion are down-regulated by lung collectin surfactant protein A. J. Immunol. 171, 417–425 (2003).

62. Rosseau, S. et al. Surfactant protein A down-regulates proinflammatory cytokine production evoked by Candida albicans in human alveolar macrophages and monocytes. J. Immunol. 163, 4495–4502 (1999).

63. McIntosh, J. C., Mervin-Blake, S., Conner, E. & Wright, J. R. Surfactant protein A protects growing cells and reduces TNF-α activity from LPS-stimulated macrophages. Am. J. Physiol. Lung Cell. Mol. Physiol. 271, L310–L319 (1996).

64. Hickling, T. P., Sim, R. B. & Malhotra, R. Induction of TNF-α release from human buffy coat cells by Pseudomonas aeruginosa is reduced by lung surfactant protein A. FEBS Lett. 437, 65–69 (1998).

65. Kremlev, S. G., Umstead, T. M. & Phelps, D. S. Surfactant protein A regulates cytokine production in the monocytic cell line THP-1. Am. J. Physiol. Lung Cell. Mol. Physiol. 272, L996–L1004 (1997).

66. Kremlev, S. G. & Phelps, D. S. Surfactant protein A stimulation of inflammatory cytokine and immunoglobulin production. Am. J. Physiol. Lung Cell. Mol. Physiol. 267, L712–L719 (1994).

67. Sano, H. et al. Pulmonary surfactant protein A modulates the cellular response to smooth and rough lipopolysaccharides by interaction with CD14. J. Immunol. 163, 387–395 (1999).

79. Schagat, T. L., Wofford, J. A. & Wright, J. R. Surfactant protein A enhances alveolar macrophage phagocytosis of apoptotic neutrophils. J. Immunol. 166, 2727–2733 (2001). The ability of SP-A to enhance phagocytosis of apoptotic cells was first reported in this publication.

80. Vandivier, R. W. et al. Role of surfactant proteins A, D, and C1q in the clearance of apoptotic cells in vivo and in vitro: calreticulin and CD91 as a common collectin receptor complex. J. Immunol. 169, 3978–3986 (2002).

Anmerkungen

The source is given for the statement: "This putative receptor gp340 has no transmembrane domain so that it is suggested that it could interact with an adaptor molecule on the surface of the cell", but not for the rest of the page which also follows the source very closely and gives the same references to the literature.

Sichter
(Hindemith), PlagProf:-)


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