The Properdin System and Immunity: I. Demonstration and Isolation of a New Serum Protein, Properdin, and Its Role in Immune Phenomena

Pillemer, Louis; Blum, Livia; Lepow, Irwin H.; Ross, Oscar A.; Todd, Earl W.; Wardlaw, A. C.

doi:10.1126/science.120.3112.279

Cited by 878 publications

(360 citation statements)

References 12 publications

Supporting

Mentioning

332

Contrasting

Unclassified

Order By: Relevance

“…This observation is in agreement with previous work utilizing different systems which assigned to properdin the function of an enhancing regulator of the alternative pathway (22,25). That Pillemer et al (31) considered properdin an essential component of the system may be explained in part by its enhancing activity which, as shown with the isolated component mixture, is most apparent at low component concentrations (Fig. 7).…”

Section: Discussionsupporting

confidence: 82%

“…As a result, C5 convertase is formed, properdin is recruited as a stabilizer of the enzyme, and membrane attack is initiated. Although properdin is the protein that originally revealed the existence of the alternative pathway and although it was thought to be the key component of the pathway (31), the results presented here shows that it fulfills no essential role in the particular bactericidal or bacteriolytic reaction examined in this study. This observation is in agreement with previous work utilizing different systems which assigned to properdin the function of an enhancing regulator of the alternative pathway (22,25).…”

Section: Discussionmentioning

confidence: 53%

See 1 more Smart Citation

Bactericidal activity of the alternative complement pathway generated from 11 isolated plasma proteins.

Schreiber¹,

Morrison²,

Podack³

et al. 1979

The Journal of Experimental Medicine

153

View full text Add to dashboard Cite

It has recently been demonstrated in this laboratory (1) that the composite mixture of the isolated alternative pathway proteins (C3, factor B, factor D, fllH, C3b inactivator, and properdin) and the isolated membrane attack pathway proteins (C5, C6, C7, C8, and C9) constitutes an intact cytolytic alternative pathway quantitatively comparable to that of human serum. In these studies, mammalian cells were used as activating target cells. Because of apparent implications for our understanding of nonspecific resistance to infections, we tested the isolated component system with respect to its ability to eradicate gram-negative bacteria. Using Escherichia coli K12 W1485 we found that the 11 component system was capable of killing the bacteria in the total absence of immunoglobulins or other serum factors. Killing was associated with distinct morphological changes of the bacteria, but not with disintegration. Disintegration or lysis required, in addition to the 11 proteins, lysozyme.Information regarding the bactericidal activity of the alternative pathway is scarce. That the proteins of the alternative pathway can be involved in bactericidal reactions against certain bacterial strains has been demonstrated through the use of factor Bdepleted human serum (2) and C4-deficient guinea pig serum (3). Whether specific antibody is required or not has remained uncertain (4-11). The requirement of lysozyme for complement-dependent lysis of gram-negative bacteria has been well documented (12,13). However, all requirements of accessory factors and of late acting complement components known to date have been elaborated by studying bacteriolysis via the classical pathway and serum reagents rather than isolated proteins. Materials and MethodsBuffers. VB: veronal-buffered physiological saline, pH 7.4; VB++: VB containing 0.15 mM CaCl2 and 0.5 mM MgClz; HBS: Hank's balanced salt solution; and GHBS: I HBS containing 0.1% gelatin.

show abstract

Section: Discussionsupporting

confidence: 82%

Section: Discussionmentioning

confidence: 53%

Bactericidal activity of the alternative complement pathway generated from 11 isolated plasma proteins.

Schreiber¹,

Morrison²,

Podack³

et al. 1979

The Journal of Experimental Medicine

153

View full text Add to dashboard Cite

show abstract

“…The AP pathway is continuously activated by hydrolysis of C3 and triggered by a range of different compounds like lipids, carbohydrates and proteins (60). In the 50's properdin was proposed as an initiator of this pathway and recent evidence supports these early findings (61,62). Another and very important function of the AP is amplification of the complement respons initiated by the other two pathways (63).…”

Section: The Complement Systemmentioning

confidence: 54%

Candidate inhibitors of porcine complement

Thorgersen¹,

Ghebremariam²,

Thurman³

et al. 2007

Molecular Immunology

View full text Add to dashboard Cite

“…The human complement factor B is one of the six components that constitute the alternative pathway activation of the complement system which provides an antibody independent route for the destruction of bacteria, neutralization of viruses and lysis of certain mammalian cells (1,2). Factor B is a heat-labile, single-chain glycoprotein of 93 kDa which is contained in human plasma in its zymogen form at a concentration of 100-400 mg/1.…”

Section: Introductionmentioning

confidence: 99%

Human complement factor B: Functional properties of a recombinant zymogen of the alternative activation pathway convertase

Schwaeble¹,

Lüttig²,

Sokolowski³

et al. 1993

Immunobiology

View full text Add to dashboard Cite

The Properdin System and Immunity: I. Demonstration and Isolation of a New Serum Protein, Properdin, and Its Role in Immune Phenomena

Cited by 878 publications

References 12 publications

Bactericidal activity of the alternative complement pathway generated from 11 isolated plasma proteins.

Bactericidal activity of the alternative complement pathway generated from 11 isolated plasma proteins.

Candidate inhibitors of porcine complement

Human complement factor B: Functional properties of a recombinant zymogen of the alternative activation pathway convertase

Contact Info

Product

Resources

About