Localization of the streptococcal C5a peptidase to the surface of group A streptococci

O'Connor, S P; Cleary, P P

doi:10.1128/iai.53.2.432-434.1986

Cited by 36 publications

(18 citation statements)

References 16 publications

(12 reference statements)

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“…Similar characteristics for generation of chemotactic activity in serum, as we here describe for B. gingivalis, have previously been found for Streptoeoeeus pyogenes and Pseudomonas aeruginosa (15,19,29,30,31). Streptoeoeeus pyogenes has a surface bound C5a peptidase that specifically removes a six-aminoacid fragment from the C terminus of human C5a and abrogates the activity of the chemotaxin (15,30).…”

Section: Discussionsupporting

confidence: 82%

Generation and degradation of the complement fragment C5a in human serum by Bacteroides gingivalis

Sundqvist¹,

Bengtson²,

Carlsson³

1988

Oral Microbiology and Immunology

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The ability of Bacteroides gingivalis to generate chemotactic activity and the complement fragment C5a in human serum was assayed. When fresh serum was incubated with B. gingivalis there was a rapid increase of chemotactic activity of the serum during the first 15 min, but longer incubation resulted in loss of chemotactic activity. When heat‐inactivated serum was incubated with B. gingivalis similar increase and decrease of the chemotactic activity of serum was also observed. The chemotactic peptide C5a could be demonstrated in all sera showing chemotactic activity. The generation of C5a and possibly also other chemotactic substances in heat‐inactivated serum by B. gingivalis may mean that this chemotactic activity was formed from serum proteins by the proteolytic activity of B. gingivalis. The proteolytic activity of B. gingivalis may also be responsible for the inactivation of C5a generated in serum.

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Section: Discussionsupporting

confidence: 82%

Generation and degradation of the complement fragment C5a in human serum by Bacteroides gingivalis

Sundqvist¹,

Bengtson²,

Carlsson³

1988

Oral Microbiology and Immunology

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“…Streptococcal infection, like infection with most pathogens, is a complex dynamic process that is presumed to involve differential expression of many gene products. O'Connor and Cleary showed that passage of streptococci in mice enriches cultures for organisms that produce SCPA (24), and others showed that M protein (19) and immunoglobulin-binding proteins (27) are similarly affected. We proposed that SCPA eliminates the C5a chemotactic gradient where it is formed by activation of complement at the cell surface and that this, in turn, delays the initial influx of granulocytes and subsequent clearing of streptococci.…”

Section: Discussionmentioning

confidence: 99%

C5a peptidase alters clearance and trafficking of group A streptococci by infected mice

et al. 1996

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Group A streptococcal C5a peptidase (SCPA) specifically cleaves the human serum chemotaxin C5a at the polymorphonuclear leukocyte (PMNL) binding site. This study tested the proposal that SCPA contributes to virulence by retarding the influx of inflammatory cells and clearance of streptococci during the first few hours after infection. To investigate the specific contribution of SCPA to the virulence of group A streptococci, scpA insertion and deletion mutants were created by directed plasmid insertion into scpA and gene replacement. The precise locations of insertion and deletion mutations were confirmed by PCR and DNA sequence analysis. The impact of mutation on virulence was investigated with a mouse air sac model of inflammation. Experiments evaluated clearance of streptococci from the air sac within 4 h after infection. SCPA ؊ streptococci were cleared more efficiently than wild-type bacteria. Localization of streptococci in lymph nodes and spleens of infected mice revealed a significant difference between mutant and wild-type streptococci. PMNLs and other granulocytes that infiltrated the air sac were quantitated by single-color flow cytometry. The total cellular infiltrate was greater and PMNLs dominated the granulocytic infiltrates of air sacs inoculated with SCPA ؊ mutant bacteria. The data obtained are consistent with the possibility that SCPA ؊ streptococci are initially cleared from the site of infection primarily by PMNLs. Moreover, mutant and wild-type streptococci followed different paths of dissemination. SCPA ؊ bacteria were transported to lymph nodes, whereas wild-type streptococci avoided transport to the lymph nodes and rapidly spread to the spleen.

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“…SCP antigen associated with intact cells was quantified by an enzymelinked immunosorbent inhibition assay (EIA) which employed rabbit anti-SCP serum (16). A standard dilution of rabbit antiserum was incubated either with dilutions of whole cells or with protein extracts before it was added to microtiter wells containing bound, highly purified SCP protein from group A streptococci (16). The amount of residual, unbound rabbit immunoglobulin G (IgG) is inversely proportional to the amount of antigen present in the preincubation mixture.…”

Section: Methodsmentioning

confidence: 99%

“…A standard curve with known concentrations of SCP antigen was simultaneously developed for comparison to unknowns. The quantity of bound rabbit IgG was determined as previously described (16).…”

Section: Methodsmentioning

confidence: 99%

Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci

et al. 1991

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Specific proteolytic destruction of the human chemotaxin, C5a, is a property of group A and B streptococcal pathogens. Here we show that virulent group G streptococci from human sources also express C5a peptidase activity. The enzyme responsible for this activity is approximately the same size as and is antigenically similar to that produced by group A streptococci. On the basis of Southern hybridization analysis with an internal fragment of the group A C5a peptidase gene (scpA) as a probe, a copy of this gene was found in the genome of all group G human isolates tested. Comparison of partial restriction maps of scpA and scpG revealed significant similarity between the two genes. Group G strains isolated from dogs and cows were found to lack C5a peptidase activity and did not hybridize to the scpA-specific probe. The association of this activity with three streptococcal species suggests that elimination of phagocyte chemotactic attractants is a more universal virulence mechanism than originally anticipated.

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Localization of the streptococcal C5a peptidase to the surface of group A streptococci

Cited by 36 publications

References 16 publications

Generation and degradation of the complement fragment C5a in human serum by Bacteroides gingivalis

Generation and degradation of the complement fragment C5a in human serum by Bacteroides gingivalis

C5a peptidase alters clearance and trafficking of group A streptococci by infected mice

Virulent human strains of group G streptococci express a C5a peptidase enzyme similar to that produced by group A streptococci

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