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1.
J Korean Med Sci ; 39(17): e154, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38711318

RESUMEN

The emergence of invasive infections attributed to group A Streptococcus (GAS) infections, has resurged since the 1980s. The recent surge in reports of toxic shock syndrome due to GAS in Japan in 2024, while sensationalized in the media, does not represent a novel infectious disease per se, as its diagnosis, treatment, and prevention are already well-established. However, due to signs of increasing incidence since 2011, further research is needed. Health authorities in neighboring countries like The Republic of Korea should not only issue travel advisories but also establish meticulous surveillance systems and initiate epidemiological studies on the genotypic variations of this disease while awaiting various epidemiological research findings from Japan.


Asunto(s)
Choque Séptico , Infecciones Estreptocócicas , Streptococcus pyogenes , Humanos , Choque Séptico/microbiología , Streptococcus pyogenes/aislamiento & purificación , Streptococcus pyogenes/genética , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/diagnóstico , República de Corea , Japón , Superantígenos/genética , Antibacterianos/uso terapéutico , Enterotoxinas/genética
2.
Immunol Cell Biol ; 102(5): 365-380, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38572664

RESUMEN

Staphylococcus aureus is a significant bacterial pathogen in both community and hospital settings, and the escalation of antimicrobial-resistant strains is of immense global concern. Vaccination is an inviting long-term strategy to curb staphylococcal disease, but identification of an effective vaccine has proved to be challenging. Three well-characterized, ubiquitous, secreted immune evasion factors from the staphylococcal superantigen-like (SSL) protein family were selected for the development of a vaccine. Wild-type SSL3, 7 and 11, which inhibit signaling through Toll-like receptor 2, cleavage of complement component 5 and neutrophil function, respectively, were successfully combined into a stable, active fusion protein (PolySSL7311). Vaccination of mice with an attenuated form of the PolySSL7311 protein stimulated significantly elevated specific immunoglobulin G and splenocyte proliferation responses to each component relative to adjuvant-only controls. Vaccination with PolySSL7311, but not a mixture of the individual proteins, led to a > 102 reduction in S. aureus tissue burden compared with controls after peritoneal challenge. Comparable antibody responses were elicited after coadministration of the vaccine in either AddaVax (an analog of MF59) or an Alum-based adjuvant; but only AddaVax conferred a significant reduction in bacterial load, aligning with other studies that suggest both cellular and humoral immune responses are necessary for protective immunity to S. aureus. Anti-sera from mice immunized with PolySSL7311, but not individual proteins, partially neutralized the functional activities of SSL7. This study confirms the importance of these SSLs for the survival of S. aureus in vivo and suggests that PolySSL7311 is a promising vaccine candidate.


Asunto(s)
Proteínas Bacterianas , Infecciones Estafilocócicas , Vacunas Estafilocócicas , Staphylococcus aureus , Superantígenos , Animales , Staphylococcus aureus/inmunología , Vacunas Estafilocócicas/inmunología , Superantígenos/inmunología , Infecciones Estafilocócicas/inmunología , Infecciones Estafilocócicas/prevención & control , Ratones , Proteínas Bacterianas/inmunología , Anticuerpos Antibacterianos/inmunología , Anticuerpos Antibacterianos/sangre , Femenino , Proteínas Recombinantes de Fusión/inmunología , Inmunoglobulina G/inmunología , Inmunoglobulina G/sangre , Estudios de Factibilidad , Vacunación , Antígenos Bacterianos/inmunología , Ratones Endogámicos BALB C , Adyuvantes Inmunológicos
3.
Front Immunol ; 15: 1365074, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38510259

RESUMEN

Staphylococcus aureus is a gram-positive bacterium that may cause intestinal inflammation by secreting enterotoxins, which commonly cause food-poisoning and gastrointestinal injuries. Staphylococcal enterotoxin B (SEB) acts as a superantigen (SAg) by binding in a bivalent manner the T-cell receptor (TCR) and the costimulatory receptor CD28, thus stimulating T cells to produce large amounts of inflammatory cytokines, which may affect intestinal epithelial barrier integrity and functions. However, the role of T cell-mediated SEB inflammatory activity remains unknown. Here we show that inflammatory cytokines produced by T cells following SEB stimulation induce dysfunctions in Caco-2 intestinal epithelial cells by promoting actin cytoskeleton remodelling and epithelial cell-cell junction down-regulation. We also found that SEB-activated inflammatory T cells promote the up-regulation of epithelial-mesenchymal transition transcription factors (EMT-TFs) in a nuclear factor-κB (NF-κB)- and STAT3-dependent manner. Finally, by using a structure-based design approach, we identified a SEB mimetic peptide (pSEB116-132) that, by blocking the binding of SEB to CD28, dampens inflammatory-mediated dysregulation of intestinal epithelial barrier.


Asunto(s)
Antígenos CD28 , Superantígenos , Humanos , Células CACO-2 , Enterotoxinas , Citocinas
4.
Genes Cells ; 29(5): 397-416, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38454012

RESUMEN

Staphylococcus aureus is a noteworthy pathogen in allergic diseases, as four staphylococcal exotoxins activate mast cells, a significant contributor to inflammation, in an IgE-independent manner. Although the adhesion of mast cells is an essential process for their immune responses, only a small number of exotoxins have been reported to affect the process. Here, we demonstrated that staphylococcal superantigen-like (SSL) 3, previously identified as a toll-like receptor 2 agonist, induced the adhesion of murine bone marrow-derived mast cells to culture substratum. SSL3-induced adhesion was mediated by fibronectin in an Arg-Gly-Asp (RGD) sequence-dependent manner, suggesting the integrins were involved in the process. Additionally, SSL3 was found to bind to an anti-adhesive surface protein CD43. SSL3 induced the adhesion of HEK293 cells expressing exogenous CD43, suggesting that CD43 is the target molecule for adhesion induced by SSL3. Evaluation of SSL3-derived mutants showed that the C-terminal region (253-326), specifically T285 and H307, are necessary to induce adhesion. SSL3 augmented the IL-13 production of mast cells in response to immunocomplex and SSL12. These findings reveal a novel function of SSL3, triggering cell adhesion and enhancing mast cell activation. This study would clarify the correlation between S. aureus and allergic diseases such as atopic dermatitis.


Asunto(s)
Adhesión Celular , Leucosialina , Mastocitos , Staphylococcus aureus , Superantígenos , Animales , Mastocitos/metabolismo , Mastocitos/inmunología , Ratones , Humanos , Superantígenos/metabolismo , Staphylococcus aureus/metabolismo , Staphylococcus aureus/inmunología , Células HEK293 , Leucosialina/metabolismo , Proteínas Bacterianas/metabolismo , Interleucina-13/metabolismo , Ratones Endogámicos C57BL
5.
Angew Chem Int Ed Engl ; 63(21): e202317552, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38497459

RESUMEN

Celiac disease (CeD) is an autoimmune disorder triggered by gluten proteins, affecting approximately 1 % of the global population. The 33-mer deamidated gliadin peptide (DGP) is a metabolically modified wheat-gluten superantigen for CeD. Here, we demonstrate that the 33-mer DGP spontaneously assembles into oligomers with a diameter of approximately 24 nm. The 33-mer DGP oligomers present two main secondary structural motifs-a major polyproline II helix and a minor ß-sheet structure. Importantly, in the presence of 33-mer DGP oligomers, there is a statistically significant increase in the permeability in the gut epithelial cell model Caco-2, accompanied by the redistribution of zonula occludens-1, a master tight junction protein. These findings provide novel molecular and supramolecular insights into the impact of 33-mer DGP in CeD and highlight the relevance of gliadin peptide oligomerization.


Asunto(s)
Enfermedad Celíaca , Enterocitos , Gliadina , Humanos , Enfermedad Celíaca/metabolismo , Enfermedad Celíaca/patología , Células CACO-2 , Gliadina/química , Gliadina/metabolismo , Enterocitos/metabolismo , Superantígenos/química , Superantígenos/metabolismo , Permeabilidad
6.
J Bacteriol ; 206(3): e0044723, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38334326

RESUMEN

Menstrual toxic shock syndrome (mTSS) is a rare but life-threatening disease associated with the use of high-absorbency tampons. The production of the Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1) superantigen is involved in nearly all cases of mTSS and is tightly controlled by regulators responding to the environment. In the prototypic mTSS strain S. aureus MN8, the major repressor of TSST-1 is the carbon catabolite protein A (CcpA), which responds to glucose concentrations in the vaginal tract. Healthy vaginal Lactobacillus species also depend on glucose for both growth and acidification of the vaginal environment through lactic acid production. We hypothesized that interactions between the vaginal microbiota [herein referred to as community state types (CSTs)] and S. aureus MN8 depend on environmental cues and that these interactions subsequently affect TSST-1 production. Using S. aureus MN8 ΔccpA growing in various glucose concentrations, we demonstrate that the supernatants from different CSTs grown in vaginally defined medium (VDM) could significantly decrease tst expression. When co-culturing CST species with MN8 ∆ccpA, we show that Lactobacillus jensenii completely inhibits TSST-1 production in conditions mimicking healthy menstruation or mTSS. Finally, we show that growing S. aureus in "unhealthy" or "transitional" CST supernatants results in higher interleukin 2 (IL-2) production from T cells. These findings suggest that dysbiotic CSTs may encourage TSST-1 production in the vaginal tract and further indicate that the CSTs are likely important for the protection from mTSS.IMPORTANCEIn this study, we investigate the impact of the vaginal microbiota against Staphylococcus aureus in conditions mimicking the vaginal environment at various stages of the menstrual cycle. We demonstrate that Lactobacillus jensenii can inhibit toxic shock syndrome toxin-1 (TSST-1) production, suggesting the potential for probiotic activity in treating and preventing menstrual toxic shock syndrome (mTSS). On the other side of the spectrum, "unhealthy" or "transient" bacteria such as Gardnerella vaginalis and Lactobacillus iners support more TSST-1 production by S. aureus, suggesting that community state types are important in the development of mTSS. This study sets forward a model for examining contact-independent interactions between pathogenic bacteria and the vaginal microbiota. It also demonstrates the necessity of replicating the environment when studying one as dynamic as the vagina.


Asunto(s)
Toxinas Bacterianas , Lactobacillus , Choque Séptico , Infecciones Estafilocócicas , Femenino , Humanos , Staphylococcus aureus/metabolismo , Choque Séptico/microbiología , Señales (Psicología) , Enterotoxinas/metabolismo , Superantígenos/metabolismo , Vagina/microbiología , Bacterias/metabolismo , Infecciones Estafilocócicas/microbiología , Glucosa/metabolismo
7.
Artículo en Inglés | MEDLINE | ID: mdl-38176845

RESUMEN

OBJECTIVES: To study the genomic epidemiology of Streptococcus pyogenes causing bloodstream infections (GAS-BSI) in a Spanish tertiary hospital during the United Kingdom invasive S. pyogenes outbreak alert. METHODS: Retrospective epidemiological analysis of GAS-BSI during the January-May 2017-2023 period. WGS was performed using Ion torrent GeneStudio™ S5 system for emm typing and identification of superantigen genes in S. pyogenes isolated during the 2022-2023 UK outbreak alert. RESULTS: During 2023, there were more cases of GAS-BSI compared to the same period of previous year with a non-significant increase in children. Fourteen isolates were sequenced. The emm1 (6/14, 42.9%) and emm12 (2/14, 14.3%) types predominated; 5 of 6 (75%) emm1 isolates were from the M1UK clone. The most detected superantigen genes were speG (12/14, 85.7%), speC (10/14, 71.4%), speJ (7/14, 50%), and speA (5/15, 33.3%). speA and speJ were predominant in M1UK clone. CONCLUSIONS: Our genomic epidemiology in 2023 is similar to the reported data from the UK outbreak alert in the same period and different from previous national S. pyogenes surveillance reports.


Asunto(s)
Infecciones Estreptocócicas , Streptococcus pyogenes , Niño , Humanos , Streptococcus pyogenes/genética , Estudios Retrospectivos , Centros de Atención Terciaria , Antígenos Bacterianos/genética , Infecciones Estreptocócicas/epidemiología , Superantígenos/genética , Reino Unido/epidemiología
8.
J Immunol Res ; 2024: 2313062, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38268531

RESUMEN

Superantigens are virulence factors secreted by microorganisms that can cause various immune diseases, such as overactivating the immune system, resulting in cytokine storms, rheumatoid arthritis, and multiple sclerosis. Some studies have demonstrated that superantigens do not require intracellular processing and instated bind as intact proteins to the antigen-binding groove of major histocompatibility complex II on antigen-presenting cells, resulting in the activation of T cells with different T-cell receptor Vß and subsequent overstimulation. To combat superantigen-mediated diseases, researchers have employed different approaches, such as antibodies and simulated peptides. However, due to the complex nature of superantigens, these approaches have not been entirely successful in achieving optimal therapeutic outcomes. CD28 interacts with members of the B7 molecule family to activate T cells. Its mimicking peptide has been suggested as a potential candidate to block superantigens, but it can lead to reduced T-cell activity while increasing the host's infection risk. Thus, this review focuses on the use of drug delivery methods to accurately target and block superantigens, while reducing the adverse effects associated with CD28 mimic peptides. We believe that this method has the potential to provide an effective and safe therapeutic strategy for superantigen-mediated diseases.


Asunto(s)
Anticuerpos , Antígenos CD28 , Células Presentadoras de Antígenos , Péptidos , Superantígenos
9.
Trends Microbiol ; 32(3): 228-230, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38182522

RESUMEN

Staphylococcus aureus is a proficient colonizer and opportunistic pathogen which can lead to vaginal dysbiosis, aerobic vaginitis, or life-threatening menstrual toxic shock syndrome. Here we explore the complex but underappreciated interactions that S. aureus may impose on the vaginal environment leading to additional disease outcomes.


Asunto(s)
Toxinas Bacterianas , Microbiota , Infecciones Estafilocócicas , Femenino , Humanos , Enterotoxinas , Staphylococcus aureus , Superantígenos
10.
J Invest Dermatol ; 144(4): 833-843.e3, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37951348

RESUMEN

Human Langerhans cells highly express CD1a antigen-presenting molecules. To understand the functions of CD1a in human skin, we used CD1a tetramers to capture T cells and determine their effector functions and TCR patterns. Skin T cells from all donors showed CD1a tetramer staining, which in three cases exceeded 10% of skin T cells. CD1a tetramer-positive T cells produced diverse cytokines, including IL-2, IL-4, IL-5, IL-9, IL-17, IL-22, and IFN-γ. Conserved TCRs often recognize nonpolymorphic antigen-presenting molecules, but no TCR motifs are known for CD1a. We detected highly conserved TCRs that used TRAV34 and TRBV28 variable genes, which is a known motif for recognition of staphylococcal enterotoxin B, a superantigen associated with atopic dermatitis. We found that these conserved TCRs did not respond to superantigen presented by CD1a, but instead showed a cross-reactive response with two targets: CD1a and staphylococcal enterotoxin B presented by classical major histocompatibility complex II. These studies identify a conserved human TCR motif for CD1a-reactive T cells. Furthermore, the demonstrated cross-reaction of T cells with two common skin-specific stimuli suggests a candidate mechanism by which CD1a and skin flora could synergize during natural immune response and in Staphylococcus-associated skin diseases.


Asunto(s)
Antígenos CD1 , Infecciones Cutáneas Estafilocócicas , Superantígenos , Humanos , Linfocitos T , Enterotoxinas , Receptores de Antígenos de Linfocitos T , Staphylococcus
11.
Int J Biol Macromol ; 256(Pt 1): 128437, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38013079

RESUMEN

Staphylococcus aureus has become a significant cause of health risks in humankind. Staphylococcal superantigens (SAgs) or enterotoxins are the key virulent factors that can exhibit acute diseases to severe life-threatening conditions. Recent literature reports S. aureus has steadily gained new enterotoxin genes over the past few decades. In spite of current knowledge of the established SAgs, several questions on putative enterotoxins are still remaining unanswered. Keeping that in mind, this study sheds light on a putative enterotoxin SEl26 to characterize its structural and functional properties. In-silico analyses indicate its close relation with the conventional SAgs, especially the zinc-binding SAgs. Additionally, important residues that are vital for the T-cell receptor (TcR) and major histocompatibility complex class II (MHC-II) interaction were predicted and compared with established SAgs. Besides, our biochemical analyses exhibited the binding of this putative enterotoxin with MHC-II, followed by regulating pro-inflammatory and anti-inflammatory cytokines.


Asunto(s)
Enterotoxinas , Staphylococcus aureus , Enterotoxinas/genética , Staphylococcus aureus/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Superantígenos/genética , Superantígenos/metabolismo , Staphylococcus , Antígenos de Histocompatibilidad Clase II/genética
12.
Mol Ther ; 32(2): 490-502, 2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38098228

RESUMEN

Inadequate T cell activation has severely limited the success of T cell engager (TCE) therapy, especially in solid tumors. Enhancing T cell activity while maintaining the tumor specificity of TCEs is the key to improving their clinical efficacy. However, currently, there needs to be more effective strategies in clinical practice. Here, we design novel superantigen-fused TCEs that display robust tumor antigen-mediated T cell activation effects. These innovative drugs are not only armed with the powerful T cell activation ability of superantigens but also retain the dependence of TCEs on tumor antigens, realizing the ingenious combination of the advantages of two existing drugs. Superantigen-fused TCEs have been preliminarily proven to have good (>30-fold more potent) and specific (>25-fold more potent) antitumor activity in vitro and in vivo. Surprisingly, they can also induce the activation of T cell chemotaxis signals, which may promote T cell infiltration and further provide an additional guarantee for improving TCE efficacy in solid tumors. Overall, this proof-of-concept provides a potential strategy for improving the clinical efficacy of TCEs.


Asunto(s)
Neoplasias , Linfocitos T , Humanos , Superantígenos/uso terapéutico , Antígenos de Neoplasias , Muerte Celular
13.
J Immunol ; 212(3): 421-432, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38108423

RESUMEN

Staphylococcal superantigens induce massive activation of T cells and inflammation, leading to toxic shock syndrome. Paradoxically, increasing evidence indicates that superantigens can also induce immunosuppression by promoting regulatory T cell (Treg) development. In this study, we demonstrate that stimulation strength plays a critical role in superantigen-mediated induction of immunosuppressive human CD4+CD25+FOXP3+ T cells. Suboptimal stimulation by a low dose (1 ng/ml) of staphylococcal enterotoxin C1 (SEC1) led to de novo generation of Treg-like CD4+CD25+FOXP3+ T cells with strong suppressive activity. In contrast, CD4+CD25+ T cells induced by optimal stimulation with high-dose SEC1 (1 µg/ml) were not immunosuppressive, despite high FOXP3 expression. Signal transduction pathway analysis revealed differential activation of the PI3K signaling pathway and expression of PTEN in optimal and suboptimal stimulation with SEC1. Additionally, we identified that FOXP3 isoforms in Treg-like cells from the suboptimal condition were located in the nucleus, whereas FOXP3 in nonsuppressive cells from the optimal condition localized in cytoplasm. Sequencing analysis of FOXP3 isoform transcripts identified five isoforms, including a FOXP3 isoform lacking partial exon 3. Overexpression of FOXP3 isoforms confirmed that both an exon 2-lacking isoform and a partial exon 3-lacking isoform confer suppressive activity. Furthermore, blockade of PI3K in optimal stimulation conditions led to induction of suppressive Treg-like cells with nuclear translocation of FOXP3, suggesting that PI3K signaling impairs induction of Tregs in a SEC1 dose-dependent manner. Taken together, these data demonstrate that the strength of activation signals determined by superantigen dose regulates subcellular localization of FOXP3 isoforms, which confers suppressive functionality.


Asunto(s)
Fosfatidilinositol 3-Quinasas , Superantígenos , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo , Linfocitos T CD4-Positivos , Linfocitos T Reguladores , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Enterotoxinas , Isoformas de Proteínas/metabolismo , Factores de Transcripción Forkhead/metabolismo
14.
Epidemiol Mikrobiol Imunol ; 72(3): 191-194, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37871993

RESUMEN

Streptococcus pyogenes causes a variety of human diseases ranging from uncomplicated respiratory tract and skin infections to severe invasive diseases possibly involving toxic shock syndrome. Besides the emm gene-encoded M protein, important virulence factors are pyrogenic exotoxins, referred to as superantigens. The National Reference Laboratory for Streptococcal Infections has newly introduced bioinformatics tools for processing S. pyogenes whole genome sequencing data. Using the SRST2 software and BV-BRC platform, WGS data of 10 S. pyogenes isolates from patients with invasive disease were analysed, and emm type, sequence type, and superantigen encoding gene profiles were determined. The Unicycler assembly pipeline with the SPAdes de novo assembler was used to assemble genome sequences from short reads.


Asunto(s)
Infecciones Estreptocócicas , Streptococcus pyogenes , Humanos , Streptococcus pyogenes/genética , Superantígenos/genética , Superantígenos/análisis , Factores de Virulencia/genética , Secuenciación Completa del Genoma , Antígenos Bacterianos/genética
15.
Bull Exp Biol Med ; 175(5): 662-666, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37861897

RESUMEN

In 82 clinical strains of Streptococcus pyogenes (group A streptococci) isolated from patients with various manifestations of streptococcal infection, emm-typing revealed 27 emm-types (n=77) with a predominance of emm-89 (n=15; 18%), emm-75 (n=9; 11%), and emm-1 (n=6; 7%); types emm-3, emm-12, and emm-58 (n=4; 5% each) were found with almost equal frequency; other types were less common. The superantigen genes speC, speG, speH, speI, speJ, speK, speL, speM, smeZ, and SSA were identified in S. pyogenes strains using multiprimer PCR; the genes of the superantigen SpeA and cysteine proteinase SpeB were detected using real-time PCR. All the studied S. pyogenes strains contained superantigen genes, and 98% of the strains had several (from 2 to 7) genes. The number of variants of these sets reached 37; 2% of the strains contained only one superantigen gene. The distribution frequencies of superantigen genes in the studied strains were: speA - 43%; speC - 38%; speG - 93%; speH - 13%; speI - 6%; speJ - 24%; speK - 13%; speL and speM - 11% each; smeZ - 98%; SSA - 15%. All studied S. pyogenes strains contained the speB gene. Our studies have demonstrated that the sets of superantigen genes of group A streptococci are characterized by pronounced diversity to some extent associated with emm-type.


Asunto(s)
Infecciones Estreptocócicas , Streptococcus pyogenes , Humanos , Streptococcus pyogenes/genética , Antígenos Bacterianos/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Superantígenos/genética , Biología Molecular , Proteínas de la Membrana Bacteriana Externa/genética
16.
Front Immunol ; 14: 1229562, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37731490

RESUMEN

Life-threatening toxic shock syndrome is often caused by the superantigen toxic shock syndrome toxin-1 (TSST-1) produced by Staphylococcus aureus. A well-known risk factor is the lack of neutralizing antibodies. To identify determinants of the anti-TSST-1 antibody response, we examined 976 participants of the German population-based epidemiological Study of Health in Pomerania (SHIP-TREND-0). We measured anti-TSST-1 antibody levels, analyzed the colonization with TSST-1-encoding S. aureus strains, and performed a genome-wide association analysis of genetic risk factors. TSST-1-specific serum IgG levels varied over a range of 4.2 logs and were elevated by a factor of 12.3 upon nasal colonization with TSST-1-encoding S. aureus. Moreover, the anti-TSST-1 antibody levels were strongly associated with HLA class II gene loci. HLA-DRB1*03:01 and HLA-DQB1*02:01 were positively, and HLA-DRB1*01:01 as well as HLA-DQB1*05:01 negatively associated with the anti-TSST-1 antibody levels. Thus, both toxin exposure and HLA alleles affect the human antibody response to TSST-1.


Asunto(s)
Choque Séptico , Infecciones Estafilocócicas , Humanos , Staphylococcus aureus , Alelos , Estudio de Asociación del Genoma Completo , Choque Séptico/genética , Superantígenos/genética , Infecciones Estafilocócicas/genética
17.
Int J Food Microbiol ; 404: 110352, 2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37549593

RESUMEN

In order to analyze and clarify the thermal stability of food poisoning Staphylococcus aureus (S. aureus) enterotoxin-like X (SElX) and the biological characteristics of digestive enzymes, and to evaluate the risk of S. aureus carrying selx gene in food poisoning, the selx gene carrying rates of 165 strains isolated from 95 food poisoning events from 2006 to 2019 were first statistically analyzed. Subsequently, the purified recombinant SElX protein was digested and heated, and the superantigen activity was verified with mouse spleen cells and peripheral blood mononuclear cells of kittens. At the same time, the emetic activity and toxicity of SElX were evaluated using the kitten vomiting animal model, mice toxin model and in vitro cell models. The results showed the selx gene carrying rate of 165 food poisoning S. aureus strains was 90.30 %. SElX had significant resistance to heat treatment and pepsin digestion (pH = 4.0 and pH = 4.5), and had good superantigen activity and emetic activity. However, there is no significant lethal effect on mice and no significant toxicity to cells. Importantly, we found that SElX had an inhibitory effect on acidic mucus of goblet cells in various segments of the small intestine. The present study investigated the stability of SElX, and confirmed the emetic activity of SElX by establishing a kitten vomiting model for the first time, suggesting that SElX is a high risk toxin of food poisoning, which will provide new ideas for the prevention and control of S. aureus food poisoning.


Asunto(s)
Enfermedades Transmitidas por los Alimentos , Intoxicación Alimentaria Estafilocócica , Infecciones Estafilocócicas , Animales , Gatos , Femenino , Ratones , Enterotoxinas/metabolismo , Staphylococcus aureus , Eméticos/metabolismo , Eméticos/farmacología , Leucocitos Mononucleares/metabolismo , Superantígenos/genética , Superantígenos/metabolismo , Vómitos/inducido químicamente , Proteínas Recombinantes
18.
Int J Mol Sci ; 24(14)2023 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-37511553

RESUMEN

As a biological macromolecule, the superantigen staphylococcal enterotoxin C2 (SEC2) is one of the most potent known T-cell activators, and it induces massive cytotoxic granule production. With this property, SEC2 and its mutants are widely regarded as immunomodulating agents for cancer therapy. In a previous study, we constructed an MHC-II-independent mutant of SEC2, named ST-4, which exhibits enhanced immunocyte stimulation and antitumor activity. However, tumor cells have different degrees of sensitivity to SEC2/ST-4. The mechanisms of immune resistance to SEs in cancer cells have not been investigated. Herein, we show that ST-4 could activate more powerful human lymphocyte granule-based cytotoxicity than SEC2. The results of RNA-seq and atomic force microscopy (AFM) analysis showed that, compared with SKOV3 cells, the softer ES-2 cells could escape from SEC2/ST-4-induced cytotoxic T-cell-mediated apoptosis by regulating cell softness through the CDC42/MLC2 pathway. Conversely, after enhancing the stiffness of cancer cells by a nonmuscle myosin-II-specific inhibitor, SEC2/ST-4 exhibited a significant antitumor effect against ES-2 cells by promoting perforin-dependent apoptosis and the S-phase arrest. Taken together, these data suggest that cell stiffness could be a key factor of resistance to SEs in ovarian cancer, and our findings may provide new insight for SE-based tumor immunotherapy.


Asunto(s)
Antineoplásicos , Enterotoxinas , Humanos , Enterotoxinas/farmacología , Enterotoxinas/metabolismo , Superantígenos/farmacología , Antineoplásicos/farmacología , Linfocitos T , Activación de Linfocitos
19.
Int J Mol Sci ; 24(13)2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37445686

RESUMEN

Bacterial superantigens (SAgs) are effective T-cell stimulatory molecules that lead to massive cytokine production. Superantigens crosslink between MHC class II molecules on the Antigen Presenting Cells (APC) and TCR on T-cells. This enables them to activate up to 20% of resting T cells, whilst conventional antigen presentation results in the activation of 0.001-0.0001% of the T cell population. These biological properties of superantigens make them attractive for use in immunotherapy. Previous studies have established the effectiveness of superantigens as therapeutic agents. This, however, was achieved with severe side effects due to the high lethality of the native toxins. Our study aims to produce superantigen-based peptides with minimum or no lethality for safer cancer treatment. In previous work, we designed and synthesized twenty overlapping SPEA-based peptides and successfully mapped regions in SPEA superantigen, causing a vasodilatory response. We screened 20 overlapping SPEA-based peptides designed and synthesized to cover the whole SPEA molecule for T-cell activation and tumor-killing ability. In addition, we designed and synthesized tumor-targeted superantigen-based peptides by fusion of TGFαL3 either from the N' or C' terminal of selected SPEA-based peptides with an eight-amino acid flexible linker in between. Our study identified parts of SPEA capable of stimulating human T-cells and producing different cytokines. We also demonstrated that the SPEA-based peptide conjugate binds specifically to cancer cells and can kill this cancer. Peptides induce T-cell activation, and tumor killing might pave the way for safer tumor-targeted superantigens (TTS). We proposed the combination of our new superantigen-based peptide conjugates with other immunotherapy techniques for effective and safer cancer treatment.


Asunto(s)
Neoplasias , Superantígenos , Humanos , Péptidos/farmacología , Linfocitos T , Neoplasias/terapia , Inmunoterapia , Enterotoxinas
20.
Eur Rev Med Pharmacol Sci ; 27(11): 5301-5309, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37318504

RESUMEN

OBJECTIVE: Staphylococcus aureus-induced toxic shock syndrome (TSS) is a rare, but potentially fatal disease with limited treatment options. The emergence of antibiotic-resistant strains has led to a pressing need for the development of effective therapies. This study aimed to identify and optimize potential drug candidates against toxic shock syndrome by targeting the pathogenic toxin protein using chromones as lead compounds. MATERIALS AND METHODS: In this study, 20 chromones were screened for their ability to bind to the target protein. The top compounds were further optimized through the addition of cycloheptane and amide groups, and the resulting compounds were evaluated for their drug-like properties using chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) profiling. RESULTS: Among the compounds screened, 7-Glucosyloxy-5-hydroxy-2-[2-(4-hydroxyphenyl) ethyl] chromone exhibited the highest binding affinity with a molecular weight of 341.40 g/mol and a binding energy of -10.0 kcal/mol. The optimized compound exhibited favorable drug-like properties, including high water solubility, synthetic accessibility, skin permeation, bioavailability, and gastrointestinal absorption. CONCLUSIONS: This study suggests that chromones can be engineered to develop effective drugs against TSS caused by S. aureus. The optimized compound has the potential to be a promising therapeutic agent for the treatment of TSS, providing new hope for patients suffering from this life-threatening disease of toxic shock syndrome.


Asunto(s)
Toxinas Bacterianas , Staphylococcus aureus Resistente a Meticilina , Choque Séptico , Infecciones Estafilocócicas , Humanos , Enterotoxinas/metabolismo , Enterotoxinas/toxicidad , Toxinas Bacterianas/metabolismo , Choque Séptico/tratamiento farmacológico , Superantígenos/metabolismo , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/metabolismo , Infecciones Estafilocócicas/tratamiento farmacológico
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