Inhibitors of reactive oxygen intermediates suppress bacterial cell wall-induced arthritis

Peritoneal and peripheral blood monocyte-macrophages from inbred Lewis (LEW) rats generate higher levels of reactive oxygen intermediates (ROI) in response to group A streptococcal cell walls (SCW) than do similar populations of cells from histocompatible Fischer rats. This differential sensitivity of the phagocytes to SCW is reflected in differences in susceptibility of the two strains to the development of arthritis in response to SCW. After systemic administration of the SCW, LEW rats develop acute and chronic erosive polyarthritis, whereas the Fischer rats are arthritis resistant. Inasmuch as these data suggested that the SCW-induced release of inflammatory cell products such as ROI might be an important contributory factor in the pathogenesis of arthritis in the LEW rats, the animals were injected with SCW and treated with ROI inhibitors. A single intraarticular injection of superoxide dismutase or catalase significantly reduced the SCW-induced inflammatory response and evolution of erosive arthritis in the treated animals (articular index 3.6 +/- 0.36 for SCW only vs 1.4 +/- 0.3 for SCW + SOD; p less than 0.001; n = 6). These data indicate that ROI play a pivotal role in synovitis and, furthermore, that suppression of these inflammatory mediators modulates both acute and chronic SCW-induced inflammation of the joint.

[Necrotizing fasciitis. A rapid fatal course of Streptococcus pyogenes, Lancefield group A serotype M1 (killer streptococci), infection]

The case history of necrotizing fasciitis in a previously healthy man aged 37 years is presented. The disease ran a rapidly fatal course. The only finding on bacterial culture was Streptococcus pyogenes, Lancefield group A, serotype M1, ("killer streptococci"). The therapeutic possibilities are briefly outlined and the importance of rapid surgical intervention is emphasized. It is concluded that this patient was actually beyond therapeutic aid less than 12 hours after admission. Necrotizing fasciitis caused by Streptococcus pyogenes, Lancefield group A, serotype M1, is comparable with meningococcal disease. It appears probable that the disease had developed in this patient as a sequel of streptococcal arthritis.

Human monoclonal antibodies: analysis of two antibodies derived from lymphocytes of a patient with acute rheumatic fever

Human monoclonal antibodies were produced by fusion of peripheral blood lymphocytes from a patient with acute rheumatic fever, with the HGPRT-non-secreting murine (Balb-c) cell line SP2/0Ag14. Heterohybridomas were selected by screening against rheumatic fever-associated group A streptococci using an ELISA, and against paraffin wax-embedded human heart sections using an immunoperoxidase technique. Two human IgM monoclonal antibodies were selected for further analysis by Western blotting and ELISA. Both antibodies demonstrated multispecificity by immunoblotting and ELISA. One of the monoclonals bound to 48 kD and 83 kD bands common to group A streptococcal and heart antigen preparations. Both human monoclonal antibodies bound to a 43 kD constituent band common to human heart and sarcolemma membrane extract. Inhibition studies performed using a competitive solid phase immunoassay confirmed shared epitopes between group A streptococci and human heart. The significance of these monoclonal antibodies to the pathogenesis of rheumatic fever is uncertain.

Lack of IgG4 antibody response to carbohydrate antigens in patients with lymphatic filariasis

It has been suggested that humans are genetically restricted from making IgG4 antibody responses to carbohydrate antigens. To test this hypothesis we examined sera from 35 patients with bancroftian filariasis (an infection known to induce very high levels of IgG4 antibodies to the parasite and known to be associated with repeated streptococcal infections) as well as from 15 normal individuals for their IgG and IgG subclass responses to streptococcal protein [streptolysin-O (SO), deoxyribonuclease B (DB)] and carbohydrate [group A carbohydrate (GAC)] antigens. Levels of IgG antibodies to all three antigens were found to be significantly higher in the filariasis patients compared to normals (P less than 0.01), and the subclass composition of these antibodies proved heterogenous. Although responses to all three antigens included IgG1, IgG2 and IgG3 antibodies and although IgG4 responses to the proteins SO and DB were significantly higher in the filariasis patients than in normals (P less than 0.001), more importantly there were no detectable anti-GAC IgG4 antibodies in either study group. These observations, coupled with our earlier finding of the absence of IgG4 responses to phosphocholine (PC) in patients with lymphatic filariasis, suggest that even the chronic antigenic stimulation of filarial helminth infection, which leads to very prominent IgG4 responses to protein antigens, cannot overcome the genetic restriction in humans for making IgG4 antibodies to carbohydrate antigens, whether of parasite or non-parasite origin.

[Comparison of the frequency of detection of autoantibodies to epidermal antigens with the level of antibodies to polysaccharide of group A Streptococcus and the number of T-suppressors in glomerulonephritis]

By the acute glomerulonephritis (GN) of streptococcal etiology, autoantibodies (AA) reacting with the basal layer of skin epithelium (BLSE) are discovered. The presence of this AA's correlate with the high level of antibodies to the streptococcal group A polysaccharide (A-PS). In the control sera such AA's and the high level antibodies to A-PS are discovered very rarely. By the GN of non-streptococcal etiology, AA's to the BLSE apparently of other specificity are obtained in some cases, in spite of the absence of antibodies to A-PS. AA's reacting with the differentiated layers of skin epithelium are discovered in the high percent of cases by GN. The presence of these AA's do not correlate with the levels of antibodies to A-PS. The reduction of the number of T-lymphocyte suppressors is established in the blood by the presence of AA's to the BLSE by GN. This question is a subject of later investigations by the different autoimmune processes. Such data can apparently corroborate the previously expressed hypothesis, that AA's to BLSE, which as a rule react with endocrine thymus epithelium, are the cause of the beginning of immunoregulatory disorders, characteristic of autoimmune processes.

Antibody levels and in vitro lymphoproliferative responses to Streptococcus pyogenes erythrogenic toxin A and mitogen of patients with rheumatic fever

We investigated the in vitro lymphoproliferative responses to a streptococcal mitogen and erythrogenic toxin A of children with acute rheumatic fever (ARF) and patients with chronic rheumatic heart disease (CRHD). Antibody levels to the streptococcal products were also analyzed in the sera of those with ARF or chronic rheumatic heart disease as well as in the sera of children with streptococcal pharyngitis or poststreptococcal glomerulonephritis. Our results demonstrated that the individuals had depressed lymphoproliferative responses during the active stage of rheumatic fever. The depressed responses were not found either to be induced by time-sensitive mitogen-specific suppressor cells or to be related to a dose-response phenomenon. On the other hand, antibody levels to the extracellular mitogens were significantly elevated in the sera of children with ARF compared with the levels in the rest of the groups. The hyperresponsiveness noted among children with ARF was found to be at a quantitative level and was not due to recognition of more epitopes, as determined by Western blotting (immunoblotting). The profile of immune responsiveness in children with ARF to the streptococcal extracellular mitogens is discussed in relation to the pathogenesis of disease.

Streptococcal throat infection: calculation of test standards and a comparison between an antigen detection test and culture

The standard minimum sensitivity (94%) and minimum specificity (89%) of a group A streptococcus (GAS) test were calculated, assuming that no more than 10% false positive and no more than 2% false negative test results should be allowed. The clinical judgement of the need for immediate antibiotic treatment in tonsillitis/pharyngitis was an unreliable indicator of a GAS aetiology, 20-29% of the results being false positive and 2-10% false negative. The rapid antigen detection test Tandem Icon Strep A was not sensitive enough to be used as a single test, though it was specific enough. The sensitivity of culture almost reached the standard demand. Two combinations of rapid test and culture (sequence testing) were superior to the rapid test, but were not significantly better than culture.

Comparison of TestPack Plus Strep A with selective and nonselective culture media for detection of group-A streptococci

The TestPack Plus Strep A (TPPSA), an immunoassay method, was compared with conventional culture methods including nonselective trypticase soy agar with 5% sheep blood and selective SXT blood agar for detection of group-A streptococci (GAS). A total of 452 throat swabs was evaluated, of which 261 (57.7%) and 191 (42.3%) were compared with culture using nonselective and selective media, respectively. Of 261 specimens evaluated on nonselective media, 71 (27.1%) were culture positive for GAS. TPPSA demonstrated a sensitivity of 91.6% and a specificity of 94.2% with positive and negative predictive values of 85.5% and 96.8%, respectively. Of 191 specimens evaluated on selective media, 44 (23.0%) were culture positive for GAS. TPPSA demonstrated a sensitivity of 93.2% and a specificity of 98.0% with positive and negative predictive values of 93.2% and 98.0%, respectively. The performance of TPPSA when compared with nonselective and selective media demonstrated a similar sensitivity, but a higher specificity was seen when compared to selective media. Overall, TPPSA was extremely easy to perform, had built-in procedural controls, required minimal technologist time, and was easy to interpret. With an accuracy of 93.5% when compared with nonselective media and 96.9% when compared with selective media, TPPSA could be recommended as a reliable method for detection of GAS.

Inhibitory effects of fibrinogen on phagocytic killing of streptococcal isolates from humans, cattle and horses

The effects of fibrinogen on phagocytic killing of Streptococcus dysgalactiae from cattle and S. equi from horses were studied in comparison to that of S. pyogenes from humans. Phagocytic killing was determined by a fluorometric microassay using glass adherent polymorphonuclear neutrophils (PMN) from the respective host species, preopsonization with homologous sera led to a dose-dependent increase in phagocytic killing of all streptococcal cultures, preincubation of streptococci with fibrinogen significantly inhibited their phagocytic killing. Fibrinogen had no effect on phagocytic killing of non-fibrinogen binding S. agalactiae cultures. Further characterization studies with S. dysgalactiae and S. pyogenes revealed that a partial inhibition of phagocytic killing could also be achieved by preincubation with monomeric beta-chains of fibrinogen. Digestion of the fibrinogen binding sites on streptococci with proteases resulted in an almost complete loss of the inhibitory effects of fibrinogen on phagocytic killing. It could thus be concluded that by binding fibrinogen animal pathogenic streptococci could evade phagocytic killing in a similar manner as M protein carrying S. pyogenes isolates from human infections.

[Preparation of monoclonal antibodies agglutinating group A, type 4 streptococci]

BALB/C mice were immunized with a partially purified M-protein fraction prepared from hot acid-extracts of a type 4, group A streptococcus, strain SS91. Two samples of monoclonal antibodies (MAb) were obtained from hybridoma cells of antibody producing spleen cells fused with NS-1 myeloma cells. Both MAb were of the subclass IgG1 having kappa-type light chains. The MAb agglutinated trypsin-digested cells of type 4 strains, but not of types 1, 2, 18, 28 and 41. This type 4-cell agglutination was inhibited by extracts of type 4 cells; strongly by hot acid-extract and partially by trypsin-extract. Hot acid-extract of type 41 cells had no inhibitory effect. Sandwich-enzyme-linked immunosorbent assay of the MAb and partially purified M-protein preparation combination against commercial T-typing sera showed that only T-type 4 antiserum reacted with the combination system. From these data, we thought that the MAb preparations were not directed to M-protein but to T-protein of type 4, group A streptococci.

A study of haemolytic streptococci isolated from outpatients in dermatological clinics

A total of 44 patients suspected of streptococcal infections were studied in outpatient clinics in Tokyo during the one year from December 1988 to December 1989. Employing bacteriological culturing and serodiagnosis, the following results were obtained. 1) There were 9 cases of impetigo and 15 cases of erysipelas with typical clinical manifestations and age distributions. 2) It seemed that some of the skin infections were caused by group A streptococci whose M-types were different from those of upper respiratory infections typically occurring in Japan. 3) The type distribution of group A streptococci found were quite similar to those isolated in Thailand or Malaysia. 4) There were found group A streptococci exhibiting unique combinations of T- and M-types, such as T11 and M9, T11 and M62 or T13-49 and MOD8 (Provisional type). 5) As for serodiagnostic method, ADNB (anti-deoxyribonuclease B) titer reflected infection by group A streptococcus only, while ASK (anti-streptokinase) and ASO (anti-streptolysin O) reflected not only group A streptococcal infections but group G infections as well.

[The detection of streptococci, the study of their immunobiological properties and the determination of lipoproteinase antibodies and anti-immunoglobulins in patients with acute rheumatic fever]

Bacteriological confirmation of the presence of group A Streptococcus (GAS) in patients with acute rheumatic fever (ARF) by means of the express method was achieved only in 15.1% of the cases and the positive growth of the culture was observed only in 12.1%. Streptococci isolated from the patients showed a low IgG-Fc receptor activity just as in the negative control. The blood serum of patients exhibited the presence of antibodies to 18 OF-serotypes among which serotypes 2, 4, 22, 28, 48, 68, 75, 77, 78, PT 2841 prevailed; their content fluctuated from 12.5 to 48.4%. There were no differences between the nature of distribution of the given antibodies depending on the presence and level of ASL-O in the blood and the presence of concomitant chronic tonsillitis. Antibodies to IgG in titres 1:10-1:40 were revealed in the blood of only 18.1% of the patients; there was some dependence of the frequency of their detection on the markedness of carditis and the presence of cardiac defects.

Altered cell-mediated immunity to group A haemolytic streptococcal antigens in chronic plaque psoriasis

The proliferative lymphocyte response to sonicated group A, beta-haemolytic streptococci (Strep-A) was measured by thymidine incorporation in 78 patients with psoriasis (guttate, chronic plaque or both). Lymphocytes from 72 of these patients were also cultured with streptokinase/streptodornase (SK/SD), and 20 of the patients with chronic plaque psoriasis were further tested with PPD, Candida albicans and sonicated Streptococcus mutans, a bacterial type not associated clinically with psoriasis. The median stimulation index (SI) of the psoriasis group to the Strep-A preparation was significantly higher than that of a group of 27 non-psoriatic individuals (P less than 0.05). Within this group, only the patients with chronic plaque psoriasis (n = 42) showed a significantly increased proliferative response compared to the non-psoriatic controls (median SI = 123.8 and 31.9, respectively, P less than 0.01). Although the lymphocyte response of the chronic plaque group to SK/SD was also markedly higher than that of the control group, this difference did not reach statistical significance. In addition, these patients did not show significantly increased responses to any of the other antigens tested, including S. mutans. No correlation was observed between the degree of proliferation to Strep-A and disease extent or activity. Similarly, ASO titres, which were raised in 11 out of 23 guttate and three out of nine chronic plaque psoriasis patients tested, did not correlate with the proliferative responses observed.

Expression and immunogenicity of a streptococcal M protein epitope inserted in Salmonella flagellin

A synthetic 48-bp oligonucleotide specifying the N-terminal 15 amino acids of M protein of Streptococcus pyogenes type 5 (plus a CTA codon, to terminate translation of genes with the insert in reverse orientation) was inserted by blunt-end ligation at the site of the 48-bp EcoRV deletion in the Salmonella flagellin gene in plasmid pLS408 (S. M. C. Newton, C. O. Jacob, and B. A. D. Stocker, Science 244: 70-72, 1989). The resulting plasmid was transferred from Escherichia coli via a restriction-negative Salmonella typhimurium strain into an aromatic-compound-dependent, flagellin-negative live-vaccine strain of Salmonella dublin to produce strain SL7127, which was motile. Expression of the inserted epitope in flagellin and its exposure at the flagellar filament surface were shown by immunoblotting and by the reaction of flagellate bacteria (immobilization, immunogold labeling) with antibody raised by injection of the corresponding synthetic peptide, S-M5(1-15). Rabbits immunized by injection of the live-vaccine strain with flagella composed of the chimeric flagellin or by injection of concentrated flagella from such bacteria developed antibodies reactive in an enzyme-linked immunosorbent assay with peptide S-M5(1-15) and with the large peptic-digest peptide pepM5. These antibodies were opsonic for type 5 streptococci. Mice that were given parenteral live SL7127 (six doses, each 1 x 10(6) to 2 x 10(6), over 8 weeks) developed titers of ca. 12,800 for the M5-specific peptides and opsonizing activity for type 5 streptococci but not for type 24 streptococci. Sera from mice similarly immunized with a control live vaccine strain without an insert in the flagellin gene did not react with the M5-specific antigens. All of the five mice given the control strain, without an insert, died after challenge with type 5 streptococci or type 24 streptococci; by contrast, four of the five mice given strain SL7127, with an insert, survived the M5 challenge, but none of the five challenged with the type 24 strain survived. Therefore, our study shows that an M protein epitope can be expressed in the context of an unrelated protein and maintain its immunogenicity. Furthermore, we demonstrate that mice can be protected against a Streptococcus pyogenes type 5 challenge by immunization with a Salmonella live vaccine with flagella made of flagellin with an insert carrying a protective epitope of M5 protein but without the cross-reactive epitopes of the complete protein.

Antibodies to N-acetylglucosamine and heparin in acute and remission phases of rheumatic fever

The etiology of acute rheumatic fever (ARF) is believed to involve an immunological response to group A streptococcal antigens. Antibodies to group A carbohydrate (A-CHO) have been reported in ARF and rheumatic heart disease patients. As N-acetylglucosamine (GlcNAc) units form the major immunodominant regions in A-CHO antigens, we investigated levels of antibodies to GlcNAc and heparin (with repeated sequences of GlcNAC) in rheumatic fever (RF) patients. Serum samples from 26 acute cases (ARF), 18 remission cases and 17 normal healthy subjects were analyzed for IgG and IgM levels of antibodies to GlcNAc and heparin. High titres of IgG antibodies to heparin and GlcNAc were observed in the ARF group in comparison with controls (p less than 0.0025 and 0.0125 respectively). There was no difference in the levels of IgM antibodies. Remission group demonstrated low titres of IgG to heparin and GlcNAc (p less than 0.01 and 0.0125 respectively) in comparison with ARF group. Heparin antibodies of IgM class was comparatively lower in remission group (p less than 0.005). While the role of these antibodies in different phases of RF needs to be investigated, we conclude that GlcNAc antibodies do not play any role in the pathogenesis of RF or rheumatic heart disease.

[The biochemical and immunological properties of group A type M 29 streptococci cultured in the presence of a bovine blood serum preparation]

The influence of the preparation of cattle blood serum on group A streptococcus, type M 29, has been studied. The study has revealed that the addition of 17% of dialysis water obtained from a fraction of cattle blood serum to the standard culture medium (3% Todd-Hewitt broth) produces changes in the amino acid composition of the cell walls of M+ variant without altering the antiphagocytic resistance of the mutant thus obtained. The dialysate of the pepsin digest of the cell walls of the mutant contains Fc-receptors and receptors to fibrinogen, while the initial strain contains only receptors to fibrinogen which are, in this case, the pepsin fragments of M protein. The study has revealed similarity in the amino acid compositions of these proteins (receptors to fibrinogens) of phenotypes M+ and M2+. Thus, our data confirm that the initial strain and the mutant belong to different phenotypes of group A streptococcus, type M 29.

Epitopes of group A streptococcal M protein shared with antigens of articular cartilage and synovium

Rabbit antisera evoked by purified pepsin-extracted group A streptococcal M proteins were screened for the presence of joint cross-reactive antibodies by indirect immunofluorescence using thin sections of mouse knee joints. Pep M1, M5, and M18 antisera contained antibodies that cross-reacted with chondrocytes, cartilage, and synovium. Immunofluorescence inhibition assays showed that some of the joint cross-reactive epitopes were shared among the three heterologous serotypes of M protein. The pep M5 joint cross-reactive epitopes were localized to three different synthetic peptides of the C-terminal region of pep M5. Immunoblot analyses showed that the M5 joint cross-reactive antibodies recognized two proteins of human synovium and cartilage of molecular mass 56 and 58 kDa. The cross-reactive antibodies binding to the 56-kDa protein were inhibited by purified vimentin in immunoblot inhibition experiments. M protein-specific antibodies from patients with acute rheumatic fever were also shown to cross-react with joint tissue in a pattern similar to the rabbit antisera. Rabbit and human M protein-specific antibodies that were bound to articular cartilage activated significant levels of complement when compared to control serum, suggesting that M protein joint cross-reactive antibodies could potentially be involved in the pathogenesis of ARF and arthritis.

[Antibodies to the rhamnose determinants of the polysaccharide of streptococci group A in the sera of rheumatism patients and donors]

In the sera of patients with recurrent rheumocarditis, and especially in cases of primary rheumatism, the level of antibodies to group A streptococcal polysaccharide (A-PS) has been found, according to the results of the enzyme immunoassay, to be considerably higher than in the sera of healthy donors. The level of antibodies to rhamnose determinants (RD) of A-PS has been determined by the inhibition of the immunoenzyme reaction with A-PS under the influence of a variant of group A streptococcus and rhamnose disaccharides with the bonds alpha 1-2 and alpha 1-3. In patients with recurrent rheumocarditis the level of antibodies to A-PS has been shown to be considerably higher than in healthy donors having these antibodies. In acute primary rheumatism a high level of antibodies to A-PS has been detected only in a few cases, and at the same time the prevalence of antibodies to the specific RD of A-PS, bound with beta-N-acetylglucosamine, is observed. In the sera of patients with recurrent rheumocarditis and donors having a high content of antibodies to the rhamnose site of A-PS antibodies, seemingly active against at least two RD, have been detected. In acute primary rheumatism an insignificant amount of antibodies to the rhamnose site of A-PS may probably cause the autoimmune process accompanying rheumatism. This suggestion is substantiated by the previously established capacity of these antibodies for inducing the suppression of cytotoxic cell reactions to microbial antigens.

Binding properties of protein Arp, a bacterial IgA-receptor

A cell surface receptor that binds to the Fc region of IgA is expressed by certain strains of group A streptococci. The physico-chemical properties and binding characteristics of this receptor, called protein Arp, were studied. Like bacterial receptors that bind IgG, protein Arp has an elongated shape and no disulfide bonds. The affinity constant of protein Arp for three different molecular forms of IgA was determined, and was found to be more than ten-fold higher for serum IgA than for two complexed forms of IgA: secretory IgA and IgA bound to alpha 1-microglobulin. Cleavage of protein Arp with CNBr resulted in a peptide corresponding to the region located outside the cell wall, except for the N-terminal 52 amino acids. This CNBr-fragment did not bind IgA, which strongly suggests that the IgA-binding region of protein Arp is located in the N-terminal part of the molecule. In addition to the binding of IgA, protein Arp also binds to IgG weakly. The pH-dependence of these two types of binding is different, with maximal binding of IgA at neutral pH (5-7) and maximal binding of IgG at acidic pH (3-5). Both for IgA and IgG, protein Arp shows strong specificity for immunoglobulins of human origin.