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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 017 01 - Diskussion
Zuletzt bearbeitet: 2014-03-10 13:25:54 Hindemith
Fehrenbach 2001, Fragment, Gesichtet, Mag, SMWFragment, Schutzlevel sysop, Verschleierung

Typus
Verschleierung
Bearbeiter
Hindemith
Gesichtet
Yes
Untersuchte Arbeit:
Seite: 17, Zeilen: 1-6
Quelle: Fehrenbach 2001
Seite(n): 34, Zeilen: l.col: 8-17
[Unlike most other lipid-rich components of cells and organs, the surfactant lipids are characterized by an] unusually high level of satured [sic] fatty acid chains, such as the predominant dipalmitoylphosphatidylcholines, which contribute substantially to the unique properties of pulmonary surfactant (van Golde et al., 1994). The protein fraction comprises a highly variable amount of serum proteins (Griese; 1999) and four apoproteins that are associated with surfactant and contribute to its specific function (Weaver and Whitsett, 1991).

Griese M. Pulmonary surfactant in health and human lung diseases: state of the art. Eur Respir J. 1999 Jun; 13 (6): 1455-76. Review.

van Golde LMG, BatenburgJJ, Robertson B The pulmonary surfactant system. Newsin Physiol Sciences 1994, 9:13-20.

Weaver TE, Whitsett JA. Function and regulation of expression of pulmonary surfactant-associated proteins. Biochem J. 1991 Jan 15; 273 (Pt2): 249-64. Review.

Unlike most other lipid-rich components of cells and organs, the surfactant lipids are characterised by an unusually high level of saturated fatty acid chains, such as the predominant dipalmitoylphosphatidylcholines, which contribute substantially to the unique properties of pulmonary surfactant (for review, see eg [8]). The protein fraction comprises a highly variable amount of serum proteins (50–90% of protein) [7] and four apoproteins that are associated with surfactant and contribute to its specific functions [9].

7. Griese M: Pulmonary surfactant in health and human lung diseases: state of the art. Eur Respir J 1999, 13:1455–1476.

8. Van Golde LMG, Batenburg JJ, Robertson B: The pulmonary surfactant system. News in Physiol Sciences 1994, 9:13–20.

9. Weaver TE, Whitsett JA: Function and regulation of pulmonary surfactant-associated proteins. Biochem J 1991, 273:249–264.

Anmerkungen

The source is not given.

The copied passage starts on the previous page: Mag/Fragment_016_27

Sichter
(Hindemith) Schumann


[2.] Mag/Fragment 017 08 - Diskussion
Zuletzt bearbeitet: 2014-03-10 13:25:43 Hindemith
BauernOpfer, Fragment, Gesichtet, Mag, SMWFragment, Schutzlevel sysop, Wright 2005

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BauernOpfer
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Hindemith
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Untersuchte Arbeit:
Seite: 17, Zeilen: 8-17
Quelle: Wright 2005
Seite(n): 58, Zeilen: r.col: 6-19
SP-B is essential for the ability of surfactant to reduce surface tension (Nogee, 2004), and SP-C has recently been shown to bind lipopolysaccharide (LPS) (Augosto et al., 2002; Augosto et al., 2003). In the absence of surfactant, surface tension is extremely high at end expiration and tends to collapse the lung. This makes breathing difficult to the extent that respiration is frequently impossible without ventilatory support and surfactant replacement. A deficiency of surfactant – which can result in “Respiratory-Distress Syndrome (RDS)” – occurs when infants are born prematurely, before their surfactant biosynthetic machinery has matured. Treatment of these premature infants with exogenous surfactant replacement reduces mortality and morbidity, because of this disease (Wright, 2005).

Augusto LA, Li J, Synguelakis M, Johansson J, Chaby R. Structural basis for interactions between lung surfactant protein C and bacterial lipopolysaccharide. J Biol Chem. 2002 Jun 28; 277 (26): 23484-92. Epub 2002 Apr 29.

Augusto LA, Synguelakis M, Johansson J, Pedron T, Girard R, Chaby R. Interaction of pulmonary surfactant protein C with CD14 and lipopolysaccharide. Infect Immun. 2003 Jan; 71 (1): 61-7.

Nogee LM. Alterations in SP-B and SP-C expression in neonatal lung disease. Annu Rev Physiol. 2004; 66: 601-23. Review.

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

SP-B is essential for the ability of surfactant to reduce surface tension3, and SP-C has recently been shown to bind lipopolysaccharide (LPS)4,5. In the absence of surfactant, surface tension is extremely high at end expiration and tends to collapse the lung. This makes breathing difficult to the extent that respiration is frequently impossible without ventilatory support and surfactant replacement. A deficiency of surfactant — which can result in RESPIRATORY-DISTRESS SYNDROME — occurs when infants are born prematurely, before their surfactant biosynthetic machinery has matured. Treatment of these babies with exogenous surfactant replacement (BOX 1) reduces mortality and morbidity due to this disease.

3. Nogee, L. M. Alterations in SP-B and SP-C expression in neonatal lung disease. Annu. Rev. Physiol. 66, 601–623 (2004).

4. Augusto, L. A. et al. Interaction of pulmonary surfactant protein C with CD14 and lipopolysaccharide. Infect. Immun. 71, 61–67 (2003).

5. Augusto, L. A., Li, J., Synguelakis, M., Johansson, J. & Chaby, R. Structural basis for interactions between lung surfactant protein C and bacterial lipopolysaccharide. J. Biol. Chem. 277, 23484–23492 (2002).

Anmerkungen

The source is given, but the extent of the copied text is not clear to the reader. Neither is it clear that the copy is almost literal. Also three references to the literature are taken from the source.

Sichter
(Hindemith) Schumann


[3.] Mag/Fragment 017 18 - Diskussion
Zuletzt bearbeitet: 2014-03-16 20:53:46 WiseWoman
BauernOpfer, Fehrenbach 2001, Fragment, Gesichtet, Mag, SMWFragment, Schutzlevel sysop

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BauernOpfer
Bearbeiter
Hindemith
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Yes
Untersuchte Arbeit:
Seite: 17, Zeilen: 18-34
Quelle: Fehrenbach 2001
Seite(n): 35, Zeilen: r.col: 17ff
The other function of alveolar surfactant relies on the nature of SP-A and SP-D as collectins. Both proteins are able to bind to the surface of various pathogens, thus acting as opsonins to facilitate their elimination by alveolar macrophages. Therefore, alveolar surfactant is also responsible for host defence (Crouch, 2000; Pison et al., 1994; Wright, 1998).

Surfactant is synthesized by alveolar type II epithelial cells and released upon appropriate stimuli by exocytosis from special intracellular storage organelles termed lamellar bodies. Once released into the alveolar space, freshly secreted lamellar body material undergoes several steps of transformation that are necessary to establish the surface-active lining layer. Cyclic compression and expansion during ventilation result in a fraction of spent surfactant that will largely be recycled by AECII. Thus, single constituents of surfactant run through several cycles before being removed by alveolar macrophages and replaced by de novo synthesis (Fehrenbach, 2001).

Although the bronchiolar Clara cells and submucosal cells also synthesize and release the mature proteins SP-A, SP-B and SP-D (Kalina et al., 1992; Voorhout et al., 1992) the alveolar type II epithelial cell is the only type of pulmonary cell that [produces all surfactant components including phospholipids as well as all four surfactant proteins. The mature 3.5 -3.7kDa small SP-C is thought to be exclusively released by AECII cells (Beers et al., 1994; Phelps and Floros et al., 1991).]


Beers MF, Kim CY, Dodia C, Fisher AB. Localization, synthesis, and processing of surfactant protein SP-C in rat lung analyzed by epitope-specific antipeptide antibodies. J Biol Chem. 1994 Aug 12; 269 (32): 20318-28.

Crouch EC. Surfactant protein-D and pulmonary host defense. Respir Res. 2000; 1 (2): 93-108. Epub 2000 Aug 25. Review.

Fehrenbach H. Alveolar epithelial type II cell: defender of the alveolus revisited. Respir Res. 2001; 2 (1): 33-46. Epub 2001 Jan 15. Review.

Kalina M, Mason RJ, Shannon JM. Surfactant protein C is expressed in alveolar type II cells but not in Clara cells of rat lung. Am J Respir Cell Mol Biol. 1992 Jun; 6 (6): 594-600.

Phelps DS, Floros J. Localization of pulmonary surfactant proteins using immunohistochemistry and tissue in situ hybridization. Exp Lung Res. 1991 Nov-Dec; 17 (6): 985-95.

Pison U, Max M, Neuendank A, Weissbach S, Pietschmann S. Host defence capacities of pulmonary surfactant: evidence for 'non-surfactant' functions of the surfactant system. Eur J Clin Invest. 1994 Sep; 24 (9): 586-99. Review.

Voorhout WF, Veenendaal T, Kuroki Y, Ogasawara Y, van Golde LM, Geuze HJ. Immunocytochemical localization of surfactant protein D (SP-D) in type II cells, Clara cells, and alveolar macrophages of rat lung. J Histochem Cytochem. 1992 Oct; 40 (10): 1589-97.

Wright JR. Host defense functions of surfactant In Lung surfactant:cellular and molecular processing. Edited by Ronney SA. Austin, Texas; R. G. Landes Company, 1998: 191-214.

Another function of alveolar surfactant postulated by Macklin [1], host defence, has attracted major scientific interest in recent years (for reviews, see [32,33]). This function of surfactant relies on the nature of SP-A and SPD as collectins. Both proteins are able to bind to the surface of various pathogens, thus acting as opsonins to facilitate their elimination by alveolar macrophages [32–34]. [...]

[...] It is synthesised by the AE2 cells and released upon appropriate stimuli by exocytosis from special intracellular storage organelles termed lamellar bodies. Once released into the alveolar space, freshly secreted lamellar body material undergoes several steps of transformation that are necessary to establish the surface-active lining layer. Cyclic compression and expansion during ventilation result in a fraction of spent surfactant that will largely be recycled by the AE2 cells. Thus, single constituents of surfactant may run through several cycles before being removed by alveolar macrophages and replaced by de novo synthesis (for comprehensive review, see [11]).

Synthesis

Although the bronchiolar Clara cells synthesise and release the mature proteins SP-A, SP-B, and SP-D (Fig. 2a) [37,38], the AE2 cell is the only type of pulmonary cell that produces all the surfactant components (phospholipids [Fig. 3] as well as all four surfactant proteins). The mature 3.5–3.7 kDa small SP-C (Fig. 2b) is thought to be released by AE2 cells only [39,40].


1. Macklin CC: The pulmonary alveolar mucoid film and the pneumonocytes. Lancet 1954, 29:1099–1104.

11. Rooney SA: Lung surfactant: cellular and molecular processing. Austin, Texas, RG Landes Company, 1998.

32. Pison U, Max M, Neuendank A, Weissbach S, Pietschmann S: Host defence capacities of pulmonary surfactant: evidence for ‘non- surfactant’ functions of the surfactant system. Eur J Clin Invest 1994, 24:586–599.

33. Wright JR: Host defense functions of surfactant. In Lung surfactant: cellular and molecular processing. Edited by Rooney SA. Austin, Texas; R. G. Landes Company, 1998:191–214.

34. Crouch EC: Surfactant protein-D and pulmonary host defense. Respir Res 2000, 1:93–108.

37. Kalina M, Mason RJ, Shannon JM: Surfactant protein C is expressed in alveolar type II cells but not in Clara cells of rat lung. Am J Respir Cell Mol Biol 1992, 6:594–600.

38. Voorhout WF, Veenendaal T, Kuroki Y, Ogasawara Y, van Golde LM, Geuze HJ: Immunocytochemical localization of surfactant protein D (SP-D) in type II cells, Clara cells, and alveolar macrophages of rat lung. J Histochem Cytochem 1992, 40: 1589–1597.

39. Phelps DS, Floros J: Localization of pulmonary surfactant proteins using immunohistochemistry and tissue in situ hybridization. Exp Lung Res 1991, 17:985–995.

40. Beers MF, Kim CY, Dodia C, Fisher AB: Localization, synthesis, and processing of surfactant protein SP-C in rat lung analyzed by epitope-specific antipeptide antibodies. J Biol Chem 1994, 269:20318–20328.

Anmerkungen

The source is mentioned on the last line of the second paragraph. It is not clear to the reader that the preceding two as well as the following two paragraphs are taken from the source almost literally, together with several references to the literature.

To be continued on the next page: Mag/Fragment_018_01

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