scholarly journals TOXIC EFFECTS OF STREPTOCOCCAL M PROTEIN ON PLATELETS AND POLYMORPHONUCLEAR LEUKOCYTES IN HUMAN BLOOD

1971 ◽  
Vol 134 (2) ◽  
pp. 351-365 ◽  
Author(s):  
Edwin H. Beachey ◽  
Gene H. Stollerman

Purified M protein isolated from Group A streptococci produced cytotoxic reactions in normal human blood in vitro. In the presence of M antigen, platelets aggregated, fused, and lysed. Polymorphonuclear leukocytes (PMN) surrounded the platelet aggregates, then became highly vacuolated and lysed. In addition, PMN progressively lost their capacity to phagocytose unrelated bacteria and to migrate in glass capillary pipettes. Platelet-PMN reactions were directly proportional to the type-specific precipitin reactivity of each M preparation and could be removed with homologous M antibody, only. Moreover, the reactivity of M protein was abolished by enzymatic digestion with trypsin, but not with lysozyme, strongly suggesting that cell-wall mucopeptide was not involved. Preliminary studies showed that platelet-PMN reactions require heat-stable and heat-labile serum factors, presumably antibody and complement. It is suggested that cytotoxic determinants are uncovered by the extraction and purification process and are intimately associated with the type-specific M determinant, possibly in a molecular complex.

1998 ◽  
Vol 66 (11) ◽  
pp. 5399-5405 ◽  
Author(s):  
Yinduo Ji ◽  
Norbert Schnitzler ◽  
Eric DeMaster ◽  
Patrick Cleary

ABSTRACT Resistance to phagocytosis is a hallmark of virulentStreptococcus pyogenes (group A streptococcus). Surface-bound C5a peptidase reduces recruitment of phagocytes to the site of infection, and hyaluronic acid capsules and/or the M protein limit the uptake of streptococci. In this study the relative impact of M and M-like proteins and the C5a peptidase on the virulence of a serotype M49 strain was assessed. The capacities of isogenic strains with an insertion mutation in emm49; with a deletion mutation in scpA49 (C5a peptidase gene); and with a deletion that removes all three M-like genes, mrp49,emm49, and enn49, to colonize mice and resist phagocytosis were compared. Experiments confirmed results obtained in an earlier study, which showed that the M49 protein was not required for in vitro resistance to phagocytosis, and also showed that the M protein was not required for colonization of mice. Failure to produce all three M-like proteins, M49, Mrp, and Enn49, significantly reduced the ability of these streptococci to resist phagocytosis in vitro but did not significantly alter the persistence of streptococci on the oral mucosa. In vitro experiments indicate that M+ streptococci are phagocytized by polymorphonuclear leukocytes that have been activated with phorbol-12-myristate 13-acetate or recombinant human C5a. This observation may explain the finding that expression of M49 protein is not essential for short-term colonization of the mouse oral mucosa.


1988 ◽  
Vol 167 (6) ◽  
pp. 1849-1859 ◽  
Author(s):  
M S Bronze ◽  
E H Beachey ◽  
J B Dale

M protein was purified to homogeneity from limited pepsin digests of intact type 19 streptococci (pep M19). The purified pep M19 when emulsified in CFA and injected into rabbits evoked type-specific and crossreactive opsonic antibodies, as well as heart-crossreactive antibodies. The NH2-terminal primary structure of pep M19 was determined and a peptide copying the first 24 amino acids [SM19(1-24)C] was chemically synthesized. Rabbits that were immunized with the unconjugated peptide developed antibodies that recognized the native pep M19, as determined by ELISA, and opsonic antibodies against type 19 streptococci, as determined by in vitro opsonophagocytosis tests. The synthetic peptide also evoked antibodies that crossreacted with a 60-kD sarcolemmal membrane protein of human myocardium. By using overlapping synthetic subpeptides as immunoinhibitors, the opsonic and heart-crossreactive epitopes of SM19(1-24)C were localized to SM19(11-24)C. Our data confirm the presence of heart-crossreactive epitopes within the primary structure of pep M19 and show that these potentially harmful autoimmune epitopes may be located in the NH2-terminal regions of certain M proteins. We conclude that continued efforts to identify the primary structures of protective and heart-crossreactive epitopes will be necessary to elucidate the pathogenesis of acute rheumatic heart disease and to develop safe and effective streptococcal vaccines.


2000 ◽  
Vol 15 (6) ◽  
pp. 772-777 ◽  
Author(s):  
Yasuhiko Nishikawa ◽  
Ryujiro Shibata ◽  
Yoshiyuki Ozono ◽  
Hiroshi Ichinose ◽  
Masanobu Miyazaki ◽  
...  

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 4182-4189 ◽  
Author(s):  
Robert Bortolussi ◽  
Kausalya Rajaraman ◽  
Gefei Qing ◽  
Rengaswami Rajaraman

Abstract We investigated the role of humoral factors in lipopolysaccharide (LPS) priming of polymorphonuclear leukocytes (PMN) using cells isolated from adults and from neonates. Plasma from newborn infants had decreased priming activity of adult plasma when mixed with LPS in studies measuring oxidative radical production of PMN after stimulation with a formyl bacterial oligopeptide (fMLP). This marked difference was not caused by LPS binding protein (LBP) because the LBP concentration in newborn and adult plasma were similar (138.4 ± 12.9 U for adults, and 126.9 ± 12.1 U for neonates, P = .53). Therefore, we attempted to identify other plasma factors that may contribute to LPS priming of PMN. We identified an LPS priming factor for PMN that is present in plasma, heat stable (56°C for 30 minutes), enhanced by heparin, and concentrated in cold precipitates of plasma. Because these properties resemble those of plasma fibronectin, we assessed the role of fibronectin in LPS priming of PMN. Although fibronectin in phosphate-buffered saline (PBS) had little effect on LPS priming of PMN, fibronectin in combination with other plasma factors appeared to play a role in LPS priming of PMN because (1) removing fibronectin from adult plasma dramatically decreased LPS priming activity from plasma (P < .005), (2) addition of fibronectin to fibronectin-depleted plasma restored its LPS plasma priming activity (P < .05), and (3) neutralizing fibronectin with antibody decreased the LPS priming activity of plasma (60.3 ± 1.3 v 30.2 ± 2.2, P < .01). Thus, plasma fibronectin plays a role in LPS priming of PMN in the presence of other factors in plasma.


1967 ◽  
Vol 126 (5) ◽  
pp. 795-818 ◽  
Author(s):  
Richard B. Roberts

The interaction in vitro between group B meningococci and rabbit polymorphonuclear leukocytes has been described. Phagocytosis did not occur in the presence of normal rabbit serum. Antiserum collected 12–21 days following one subcutaneous inoculation of living log phase meningococci exhibited opsonic activity with type specificity; this opsonic action depended on both heat-labile and heat-stable factors. Following ingestion by granulocytes, meningococci were rapidly killed. These studies suggest that group B meningococcal strains contain specific antiphagocytic surface factors of an as yet unknown chemical nature. Antisera obtained 4 or more wk after immunization showed bactericidal activity with the same type specificity as opsonic activity. This bactericidal activity was also lost after heating and restored by the addition of normal serum. Further studies on opsonins and bactericidins for meningococci may shed light on virulence factors in these microorganisms, and may prove useful for a more precise classification of meningococci according to type rather than group specificity.


1975 ◽  
Vol 11 (2) ◽  
pp. 337-342 ◽  
Author(s):  
D A Casciato ◽  
J E Rosenblatt ◽  
L S Goldberg ◽  
R Bluestone

1974 ◽  
Vol 32 (02/03) ◽  
pp. 266-276
Author(s):  
Carl D. Jacobsen ◽  
John C. Hoak ◽  
Kenneth K. WU ◽  
Glenna L. Fry
Keyword(s):  

SummaryIn serum from patients with DIC at least 3 different FR-antigenic components could be found. It was difficult to demonstrate these components in the corresponding plasma samples. It is possible that a portion of these antigens formed as a result of in vitro clotting despite the presence of proteolytic inhibitors. These results suggest that the interpretation of “increased split products in serum” may be more complex than current concepts indicate.


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