Complement fixation by antibodies to the alpha toxin of Staphylococcus aureus

1982 ◽  
Vol 28 (10) ◽  
pp. 1127-1132 ◽  
Author(s):  
Ching Y. Lo ◽  
Hugh B. Fackrell ◽  
Gary M. Barei
Keyword(s):  
Staphylococcus Aureus ◽  
Complement Fixation ◽  
Erythrocyte Membranes ◽  
Alpha Toxin ◽  
In Vivo Experiments ◽  
Carrier Erythrocytes ◽  
Human Sera ◽  
Normal Humans ◽  
Normal Human

When rabbits were injected with the heat-denatured alpha toxin (toxoid) of Staphylococcus aureus, the immune response was demonstrated by an increase in antitoxin that fixed complement. Such antitoxin was detected in 72% of normal human sera. After fractionation of the antitoxin into two types (the antibinding antibodies and the indirect hemagglutinating antibodies), both types of antibodies were found to fix complement in the standard serological complement fixation test. In addition, the indirect hemagglutinating antibodies were capable of fixing complement when the antigen (alpha toxin or toxoid) was covalently or noncovalently bound to erythrocyte membranes. The fixation of complement by membrane-bound immune complexes did not result in lysis of the carrier erythrocytes. The prevalence of complement-fixing antitoxin in normal humans and animals raised the concern that the outcome of in vivo experiments involving alpha toxin could be influenced by the immune status of the host.

Incorporation of the Non-Human Sialic Acid Neu5Gc into Human Leukemic Cells and Targeting by Natural Human Anti-Neu5Gc Antibodies.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3866-3866
Author(s):  
Dzung H. Nguyen ◽  
Pam Tangvoranuntakul ◽  
Ajit Varki
Keyword(s):  
Sialic Acid ◽  
Blood Cells ◽  
Leukemic Cells ◽  
Therapeutic Window ◽  
Last Common Ancestor ◽  
Activated T Cells ◽  
Human Sera ◽  
Normal Humans ◽  
Normal Human

Abstract Humans are incapable of synthesizing the common mammalian cell surface sialic acid N-glycolylneuraminic acid (Neu5Gc), due to an irreversible genetic mutation that occurred after our last common ancestor with great apes. Despite this, we found trace levels of Neu5Gc in certain normal human tissues, and higher levels in fetal and malignant tissues, apparently due to incorporation from dietary sources. Circulating anti-Neu5Gc antibodies also occur in most normal humans, with marked individual variations in levels. We now show that while normal human blood cells metabolically incorporate very little free Neu5Gc from the culture medium, human leukemic cell lines do so efficiently, displaying it on their cell surfaces, as detected by flow cytometry using a monospecific polyclonal chicken antibody, and confirmed chemically by HPLC. Specific deposition of IgG from Neu5Gc-reactive human sera onto Neu5Gc-expressing leukemic cells could be demonstrated. This was associated with lytic cell killing, apoptosis, and antibody-dependent cell-mediated cytotoxicity. Human sera with low levels of anti-Neu5Gc antibodies did not mediate such effects. These data show for the first time that the “natural” anti-Neu5Gc antibodies found in normal humans can be functionally active. The selective incorporation of Neu5Gc into leukemic cells could provide an approach for targeting leukemic cells in vivo, via naturally occurring Neu5Gc-specific antibodies. However, in contrast to unstimulated blood cells, activated human T-lymphocytes also incorporated some Neu5Gc, albeit to a lesser degree than leukemic cells, allowing IgG binding and complement deposition. Thus, exposure of rapidly dividing activated T cells to Neu5Gc could potentially affect ongoing immune responses. Since incorporation into leukemic cells was most efficient, it may still be possible to define a therapeutic window to selectively target malignant cells.

scholarly journals ON THE PRESENCE IN SYPHILITIC SERUM OF ANTIBODIES TO SPIROCHETES, THEIR RELATION TO SO CALLED WASSERMANN REAGIN, AND THEIR SIGNIFICANCE FOR THE SERODIAGNOSIS OF SYPHILIS

1940 ◽  
Vol 71 (2) ◽  
pp. 215-230 ◽  
Author(s):  
Harry Eagle ◽  
Ralph B. Hogan
Keyword(s):  
Complement Fixation ◽  
High Titre ◽  
Beef Heart ◽  
Mammalian Tissue ◽  
Practical Utility ◽  
Tissue Extracts ◽  
Human Sera ◽  
Antigenic Material ◽  
Normal Human ◽  
Serodiagnosis Of Syphilis

1. In confirmation of Gaehtgens, syphilitic human sera give positive complement fixation with cultures of so called T. pallidum (Reiter strain). Syphilitic rabbit sera are equally reactive. Syphilitic human and rabbit sera agglutinate these cultures, often in high titre (Beck). 2. Normal rabbit sera react weakly with the culture to give both agglutination and complement fixation in low titre. Normal human sera, despite the fact that they contain agglutinins in low titre, fail to fix complement with the Reiter strain of cultured spirochetes. Confirming Gaehtgens, the latter reaction is therefore of practical utility for the serum diagnosis of syphilis. 3. When syphilitic serum is heated at 63°C., there is no demonstrable difference in the thermolability of the antibody to spirochetes, and of the reagin which determines the Wassermann and flocculation tests. 4. (a) The absorption of syphilitic serum by spirochetal suspensions removes all reactivity, not only for the spirochetes, but for tissue lipoids (alcoholic beef heart extract) as well; the sera become Wassermann- and flocculation-negative. (b) Absorption of syphilitic serum with tissue lipoids renders the Wassermann and flocculation tests negative, but does not demonstrably change the reactivity of the serum with spirochetes. (c) Rabbits immunized to beef heart lipoid develop spirochetal agglutinins and complement-fixing antibodies (Reiter strain) in high titre. 5. It is concluded that these cultured spirochetes contain antigenic material serologically related to a substance present in mammalian tissue, as well as other antigenic factors not present in such extracts, but equally reactive with syphilitic serum. 6. These findings support the thesis that the primary serologic change in syphilis is the development of antibodies to T. pallidum. The Wassermann and flocculation tests would be explained on the basis that the tissue extracts used as "antigen" in these tests contain one or more substances serologically related to antigenic components of T. pallidum. Similarly, the cultured Reiter strain of spirochete is apparently sufficiently close serologically to T. pallidum to be agglutinated by and to give complement fixation with the antibodies to T. pallidum present in syphilitic serum. 7. Since suspensions of cultured spirochetes contain antigenic factors which react specifically with syphilitic serum, some of which are not present in ordinary Wassermann and flocculation "antigens," they may prove even more valuable than those tissue extracts in the serodiagnosis of syphilis.

The Nature of Alpha Toxin Production by Staphylococcus aureus Grown in vivo.

1965 ◽  
Vol 119 (1) ◽  
pp. 74-77 ◽  
Author(s):  
F. A. Kapral ◽  
A. M. Keogh ◽  
J. H. Taubler
Keyword(s):  
Staphylococcus Aureus ◽  
Toxin Production ◽  
Alpha Toxin

scholarly journals Natural And Immune Bactericidins For The Gonococcus

1936 ◽  
Vol 36 (3) ◽  
pp. 355-362 ◽  
Author(s):  
Y. B. Abdoosh
Keyword(s):  
Complement Fixation ◽  
Mammalian Species ◽  
Bactericidal Action ◽  
Probable Significance ◽  
Human Sera ◽  
Normal Human

1. Normal human sera have no natural bactericidins active against strains of gonococci.2. Normal sera from eleven other mammalian species showed a powerful bactericidal action against various strains of gonococci.3. The serological heterogeneity of the gonococcus group revealed by agglutination and complement fixation is again demonstrated in the bactericidal test with immune antiserum.4. There is a steady rise in the incidence of positive bactericidal action in the sera of patients following the progress of infection with the gonococcus.5. The probable significance of these bactericidins, natural and immune, discussed.Acknowledgments. I wish to express my gratitude to Dr Ledingham for the facilities for work granted me at the Lister Institute and to Dr Schiitze for his kind help and critical advice during the progress of this investigation.

scholarly journals Staphylococcus aureus Exotoxins Are Present In Vivo in Tampons

2010 ◽  
Vol 17 (5) ◽  
pp. 722-727 ◽  
Author(s):  
Patrick M. Schlievert ◽  
Kimberly A. Nemeth ◽  
Catherine C. Davis ◽  
Marnie L. Peterson ◽  
Bruce E. Jones
Keyword(s):  
Staphylococcus Aureus ◽  
Toxic Shock Syndrome ◽  
Ex Vivo ◽  
Menstrual Blood ◽  
Alpha Toxin ◽  
Toxic Shock ◽  
Inflammatory Protein ◽  
Ifn Γ ◽  
Staphylococcal Toxic Shock Syndrome

ABSTRACT Staphylococcal toxic shock syndrome toxin 1 (TSST-1) is the cause of menstrual toxic shock syndrome (mTSS) associated with vaginal colonization by Staphylococcus aureus. In this pilot study, we measured TSST-1 and alpha-toxin, another exotoxin, on used tampons from four healthy women with S. aureus on tampons and from two women with tampon-associated mTSS. Tampons from all six women were sectioned into approximately 0.5-cm3 pieces, some containing menstrual blood and some lacking menstrual blood. The pH of tampon sections with or without menstrual blood was neutral. S. aureus CFU were present in tampon sections at approximately equivalent counts (total counts were 1 × 108 to 2 × 109 CFU/tampon). TSST-1 (2 to 80 μg/tampon) and alpha-toxin (28 to 30 μg/tampon) were present only in the sections containing little or no menstrual blood (low hemoglobin density). In the tampons from TSS patients, the cytokine gamma interferon (IFN-γ) was detected only in menstrual-blood-containing sections, whereas the chemokines macrophage inflammatory protein 3α and interleukin-8 were detected in all sections. Thus, IFN-γ was being produced systemically, whereas the chemokines were being produced both locally by epithelial cells and systemically. The data show that S. aureus exotoxins can be identified in tampons ex vivo in sites with low hemoglobin density.

scholarly journals Marine Fungal Cerebroside Flavuside B Protects HaCaT Keratinocytes against Staphylococcus aureus Induced Damage

Marine Drugs ◽  
2021 ◽  
Vol 19 (10) ◽  
pp. 553
Author(s):  
Ekaterina A. Chingizova ◽  
Ekaterina S. Menchinskaya ◽  
Artur R. Chingizov ◽  
Evgeny A. Pislyagin ◽  
Elena V. Girich ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Staphylococcus Aureus ◽  
Skin Lesions ◽  
Epidermal Keratinocytes ◽  
Negative Consequences ◽  
Human Epidermal Keratinocytes ◽  
In Vivo Experiments ◽  
Dual Action ◽  
Anti Inflammatory

Cerebrosides are glycosylated sphingolipids, and in mammals they contribute to the pro-/anti-inflammatory properties and innate antimicrobial activity of the skin and mucosal surfaces. Staphylococcus aureus infection can develop, not only from minor scratches of the skin, but this pathogen can also actively promote epithelial breach. The effect of cerebroside flavuside B from marine sediment-derived fungus Penicillium islandicum (Aniva Bay, the Sea of Okhotsk) on viability, apoptosis, total caspase activity, and cell cycle in human epidermal keratinocytes HaCaT line co-cultivated with S. aureus, as well as influence of flavuside B on LPS-treated HaCaT cells were studied. Influence of flavuside B on bacterial growth and biofilm formation of S. aureus and its effect on the enzymatic activity of sortase A was also investigated. It was found S. aureus co-cultivated with keratinocytes induces caspase-depended apoptosis and cell death, arrest cell cycle in the G0/G1 phase, and increases in cellular immune inflammation. Cerebroside flavuside B has demonstrated its antimicrobial and anti-inflammatory properties, substantially eliminating all the negative consequences caused by co-cultivation of keratinocytes with S. aureus or bacterial LPS. The dual action of flavuside B may be highly effective in the treatment of bacterial skin lesions and will be studied in the future in in vivo experiments.

scholarly journals Regulated Antisense RNA Eliminates Alpha-Toxin Virulence in Staphylococcus aureus Infection

1999 ◽  
Vol 181 (21) ◽  
pp. 6585-6590 ◽  
Author(s):  
Yinduo Ji ◽  
Andrea Marra ◽  
Martin Rosenberg ◽  
Gary Woodnutt
Keyword(s):  
Gene Expression ◽  
Staphylococcus Aureus ◽  
Antisense Rna ◽  
Expression System ◽  
Toxin Gene ◽  
Critical Element ◽  
Bacterial Cells ◽  
Alpha Toxin

ABSTRACT The ability to selectively disrupt gene function remains a critical element in elucidating information regarding gene essentiality for bacterial growth and/or pathogenesis. In this study, we adapted atet regulatory expression system for use inStaphylococcus aureus, with the goal of downregulating gene expression via induction of antisense RNA. We demonstrate that this system exhibits a 50- to 100-fold dose-dependent level of induction in bacterial cells grown in culture (i.e., in vitro) and also functions in mice (i.e., in vivo) following oral administration of inducer. To determine whether induced antisense RNA could interfere with chromosomally derived gene expression, we cloned a fragment of theS. aureus alpha-toxin gene (hla) in antisense orientation downstream of the tet promoter system and introduced the construct into S. aureus. Induced antisensehla RNA downregulated chromosomally derived hlagene expression in vitro approximately 14-fold. Similarly, induction ofhla antisense RNA in vivo dramatically reduced alpha-toxin expression in two different murine models of S. aureusinfection. Most importantly, this reduction completely eliminated the lethality of the infection. These results indicate that thetet regulatory system functions efficiently in S. aureus and induced antisense RNA can effectively downregulate chromosomal gene expression both in vitro and in vivo.

scholarly journals Alanine Scanning Mutagenesis of the MEDI4893 (Suvratoxumab) Epitope Reduces Alpha Toxin Lytic Activity In Vitro and Staphylococcus aureus Fitness in Infection Models

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
C. Tkaczyk ◽  
E. Semenova ◽  
Y. Y. Shi ◽  
K. Rosenthal ◽  
V. Oganesyan ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pore Formation ◽  
Severe Disease ◽  
Treatment Strategies ◽  
Lytic Activity ◽  
Alpha Toxin ◽  
Alanine Scanning Mutagenesis ◽  
Content Type

ABSTRACT Alpha toxin (AT) is a cytolytic pore-forming toxin that plays a key role in Staphylococcus aureus pathogenesis; consequently, extensive research was undertaken to understand the AT mechanism of action and its utility as a target for novel prophylaxis and treatment strategies against S. aureus infections. MEDI4893 (suvratoxumab) is a human anti-AT IgG1 monoclonal antibody (MAb) that targets AT and is currently in phase 2 clinical development. As shown previously, the MEDI4893-binding epitope on AT is comprised of the highly conserved amino acid regions 177 to 200 and 261 to 271, suggesting these amino acids are important for AT function. To test this hypothesis and gain insight into the effect of mutations in the epitope on AT neutralization by MEDI4893, nine MEDI4893 contact residues in AT were individually mutated to alanine. Consistent with our hypothesis, 8 out of 9 mutants exhibited >2-fold loss in lytic activity resulting from a defect in cell binding and pore formation. MEDI4893 binding affinity was reduced >2-fold (2- to 27-fold) for 7 out of 9 mutants, and no binding was detected for the W187A mutant. MEDI4893 effectively neutralized all of the lytic mutants in vitro and in vivo. When the defective mutants were introduced into an S. aureus clinical isolate, the mutant-expressing strains exhibited less severe disease in mouse models and were effectively neutralized by MEDI4893. These results indicate the MEDI4893 epitope is highly conserved due in part to its role in AT pore formation and bacterial fitness, thereby decreasing the likelihood for the emergence of MAb-resistant variants.

Interactions entre Staphylococcus aureus et Pseudomonas aeruginosa dans des cultures in vitro et au cours d'infections expérimentales

1972 ◽  
Vol 18 (10) ◽  
pp. 1531-1541 ◽  
Author(s):  
J. de Repentigny ◽  
L. G. Mathieu ◽  
T. Gadbois
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Pure Culture ◽  
Maximum Growth ◽  
Mixed Cultures ◽  
Mixed Infections ◽  
Alpha Toxin ◽  
Culture Supernatants

Staphylococcus aureus and Pseudomonas aeruginosa are often found in succession or in association in infections. To study experimentally their interactions, we have used systems of growth or survival of mixed cultures of both species in vitro in a semisynthetic medium and in vivo in the peritoneal cavity of mice. Conditions for maximum growth in vitro of both species in mixed cultures are about similar to those in pure culture when the pH is maintained between 6.0 and 7.3. The inhibition of S. aureus growth by some antimetabolites or antibiotics, e.g., 5-methyltryptophan and D-cycloserine, is antagonized in mixed cultures. Staphylococcus coagulase, DNase, and alpha toxin were present either in mixed cultures or after mixing pure culture supernatants of both species, but P. aeruginosa slime was not observed in these conditions. In vivo, the survival of S. aureus seemed greater in mixed infections with P. aeruginosa than in those with S. aureus alone. In our systems, S. aureus may have benefited from the presence of P. aeruginosa whereas the reverse was not observed. These observations on interbacterial ecology could help to explain the importance and the behavior of some species at the initiation of pyogenic infections, either their interactions or their selection.

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