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Incidence of Oxacillin-Susceptible mecA-Positive Staphylococcus aureus (OS-MRSA) Isolates and TSST-1 Virulence Factor Among High School Students in Tabriz, Northwest of Iran. ARCHIVES OF CLINICAL INFECTIOUS DISEASES 2019. [DOI: 10.5812/archcid.85341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Tripathi A, Kern R, Conley DB, Seiberling K, Klemens JC, Harris KE, Suh L, Huang J, Grammer LC. Staphylococcal Exotoxins and Nasal Polyposis: Analysis of Systemic and Local Responses. ACTA ACUST UNITED AC 2018. [DOI: 10.1177/194589240501900401] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Background Staphylococcal exotoxins have been implicated in the pathogenesis of several chronic inflammatory diseases including atopic dermatitis (AD), asthma, and, most recently, chronic rhinosinusitis with nasal polyposis (CRS/NP). In severe AD, these toxins act both as superantigens (SAg), triggering massive T-cell activation, and as conventional allergens, triggering toxin-specific immunoglobulin E (IgE) in the serum. In CRS/NP, evidence for both processes has been reported but it is unclear whether these processes are linked. The aim of this study was to correlate SAg activity as inferred by staphylococcal-specific T-cell receptor (TCR) V-β expansion in the polyp and blood of CRS/NP patients with staphylococcal-specific anti-IgE antibodies in the serum. Methods IgE antibodies to staphylococcal exotoxin A (SEA), staphylococcal exotoxin B (SEB), and toxic shock syndrome toxin (TSST) 1 were measured in the serum of 12 individuals with CRS/NP before functional endoscopic sinus surgery. Flow cytometry was used to analyze the SEA, SEB, and TSST-1–specific TCR V-β domains on the T cells from the polyp and blood of these patients. Results Serum SEA-, SEB-, and TSST-1-specific IgE antibodies were detected in 0/12 (0%), 6/12 (50.0%), and 9/12 (75%) of CRS/NP patients, respectively. Evidence of SAg effect in the polyp lymphocytes (TCR V-β expansion in both CD4+ and CD8+ subsets) was noted in 7/12 (58.3%) patients. Five of 6 CRS/NP patients had overlapping evidence of a systemic IgE response and TCR V-β expansion, suggestive of exposure to the same exotoxin. No patients had evidence a SAg effect in blood lymphocytes. Nine of 12 subjects also had coexistent asthma. Conclusion These results provide evidence for a local SAg effect in 7/12 (58.3%) polyp patients and establish a positive correlation of V-β expansion with the presence of corresponding toxin-specific IgE in the serum.
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Affiliation(s)
- Anju Tripathi
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Robert Kern
- Department of Otolaryngology–Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - David B. Conley
- Department of Otolaryngology–Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Kristin Seiberling
- Department of Otolaryngology–Head and Neck Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Julie C. Klemens
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Kathleen E. Harris
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Lydia Suh
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Jie Huang
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Leslie C. Grammer
- Division of Allergy-Immunology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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Zhou P, Zhang XS, Xu ZB, Gao SX, Zheng QW, Xu MZ, Shen L, Yu F, Guan JC. Staphylococcal enterotoxin B administration in pregnant rats alters the splenic lymphocyte response in adult offspring rats. BMC Microbiol 2017; 17:1. [PMID: 28049431 PMCID: PMC5210265 DOI: 10.1186/s12866-016-0921-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 12/22/2016] [Indexed: 01/07/2023] Open
Abstract
Background Our previous study suggested that SEB exposure in pregnant rats could lead to the change of T cells subpopulation in both peripheral blood and thymus of the offspring rats. However, rarely is known about the influence of SEB exposure in pregnant rats on T cell subpopulation in the spleens of offspring rats. Results SEB was intravenously administered to the pregnant rats at gestational day 16 in this study. The percentages, in vivo and in vitro responses of CD4 and CD8 T cells were investigated with flow cytometry. The prenatal SEB exposure obviously increased splenic CD4 T cell percentages of both neonates and adult offspring rats, and obviously reduced splenic CD8 T cell percentages of both the fifth day neonates and adult offspring rats. After spleens in the adult offspring rats were re-stimulated with SEB in vivo or in vitro, in vivo SEB stimulation could lead to the marked decrease of splenic CD4 T cell percentage and the marked increase of splenic CD8 T cell percentage. While in vitro SEB stimulation to the cultured splenocytes markedly decreased the proliferation of the splenic lymphocytes and the CD4 T cell percentage, and had no influence on CD8 T cell percentage. Conclusion The prenatal SEB exposure could alter the percentages of CD4/CD8 T cell subpopulation and the response of CD4 and CD8 T cells to the in vivo and in vitro secondary SEB stimulation in the splenocytes of adult offspring rats.
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Affiliation(s)
- Ping Zhou
- Department of Microbiology and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, 2600 Dong Hai Avenue, Bengbu, Anhui, 233030, People's Republic of China
| | - Xin-Sheng Zhang
- Editorial Board of Journal of Bengbu Medical College, Bengbu Medical College, Bengbu, Anhui, 233030, People's Republic of China
| | - Zhi-Ben Xu
- Department of Microbiology and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, 2600 Dong Hai Avenue, Bengbu, Anhui, 233030, People's Republic of China
| | - Shu-Xian Gao
- Department of Microbiology and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, 2600 Dong Hai Avenue, Bengbu, Anhui, 233030, People's Republic of China
| | - Qing-Wei Zheng
- Department of Microbiology and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, 2600 Dong Hai Avenue, Bengbu, Anhui, 233030, People's Republic of China
| | - Ming-Zhu Xu
- Department of Life Sciences, Bengbu Medical College, Bengbu, Anhui, 233030, People's Republic of China
| | - Lin Shen
- Scientific Research Center, Bengbu Medical College, Bengbu, Anhui, 233030, People's Republic of China
| | - Feng Yu
- Huzhou University Schools of Medicine and Nursing Science, Huzhou, Zhejiang, 313000, People's Republic of China
| | - Jun-Chang Guan
- Department of Microbiology and Anhui Key Laboratory of Infection and Immunity, Bengbu Medical College, 2600 Dong Hai Avenue, Bengbu, Anhui, 233030, People's Republic of China.
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Abstract
Toxic shock syndrome (TSS) represents a heterogeneous group of disorders that results in hypotension, multiorgan system involvement, and a characteristic rash or soft tissue infection caused by staphylococcal or streptococcal exotoxins and enterotoxins. Staphylococcal TSS emerged in the late 1970s as an illness associated with highly absorbent tampons; subsequently it has been described with postoperative infections, burns, and various viral illnesses. Although the morbidity rate associated with staphylococcal TSS may be high, the mortality rate approximates 5%. Streptococcal TSS has emerged in the 1980s and into the 1990s as a disorder that results in rapid progression of soft tissue infection in the form of cellulitis, myositis, or necrotizing fasciitis due to pyogenic streptococcal group A exotoxin. The rapidity of progression of local infection to hypotension and multiorgan failure results in a mortality rate of 30–70%. In both forms of TSS, staphylococcal and streptococcal exotoxins function as superantigens, a unique mechanism of immune activation that results in an exuberant T-cell response and profound cytokine expression. The role of antibiotics is reviewed. The use of clindamycin in streptococcal TSS and the potential therapeutic role of intravenous immunoglobulin in both forms of this disorder are discussed as well.
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Affiliation(s)
- Paul F. Dellaripa
- Section of Pulmonary and Critical Care Medicine and Section of Rheumatology, Lahey Clinic Medical Center, Burlington, MA
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Association between specific IgE to Staphylococcus aureus enterotoxins A and B and asthma control. Ann Allergy Asthma Immunol 2015. [PMID: 26208759 DOI: 10.1016/j.anai.2015.06.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
BACKGROUND Recent studies have found that serum levels of Staphylococcus aureus enterotoxin (SE)-IgE are higher in patients with severe asthma compared with patients with nonsevere asthma. However, the association between SE-IgE and asthma control is not fully understood. Furthermore, SEA and SEB were the first reported SEs and subdivided into different groups. The influences of SEA-IgE and SEB-IgE on asthma control have not been elucidated. OBJECTIVE To determine the relevance of SEA- and SEB-IgE in patients with adult asthma and to investigate the association of SEA-IgE, SEB-IgE, and asthma control, respectively. METHODS The serum concentrations of SEA- and SEB-IgE in 172 adults with asthma were measured with a fluorescent enzyme immunoassay. RESULTS The prevalence of SEA- and SEB-IgE was 16.2% and 22.1%, respectively. Total IgE levels and the prevalence of atopic dermatitis were higher in SEA-IgE- and SEB-IgE-positive patients than in SEA-IgE- and SEB-IgE-negative patients, respectively; more SEA-IgE- and SEB-IgE-positive patients owned pets. Sensitization to SEA was associated with a younger mean age and a younger mean age at asthma onset. Multiple regression analysis indicated an association between total IgE levels and SEB-IgE. The prevalence of poorly uncontrolled asthma was significantly higher in SEA-IgE-positive patients than in SEA-IgE-negative patients. In addition, fractional exhaled nitric oxide levels were higher in SEA-IgE-positive patients than in SEA-IgE-negative patients. Logistic regression analysis also identified an association between SEA-IgE and poor asthma control. CONCLUSION Our findings indicate that sensitization to SE, in particular SEA rather than SEB, is associated with poor asthma control in adults with asthma.
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Lin YC, Peterson ML. New insights into the prevention of staphylococcal infections and toxic shock syndrome. Expert Rev Clin Pharmacol 2014; 3:753-767. [PMID: 21625323 DOI: 10.1586/ecp.10.121] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Staphylococcus aureus is a major human pathogen capable of causing various diseases, from skin infections to life-threatening pneumonia and toxic shock syndrome. S. aureus exoproteins, including superantigens, contribute significantly to the pathogenesis of this organism. Antibiotics inhibit growth, but often provide no protection from S. aureus exoproteins. With the emergence of antibiotic-resistant S. aureus, new therapeutic options to treat or prevent S. aureus-associated diseases are critical. Most S. aureus infections begin on the skin or mucosal surfaces from direct inflammatory or cytotoxic effects of exotoxins. Therefore, antitoxin therapies that prevent toxin production and prevent their effects on host cells are being researched. Current treatments for staphylococcal diseases and recent developments in antitoxin therapeutic agents and vaccines are reviewed.
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Affiliation(s)
- Ying-Chi Lin
- Department of Experimental and Clinical Pharmacology, University of Minnesota, Minneapolis, MN 55455 USA
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Guven M, Karabay O, Akidil O, Yilmaz MS, Yildirim M. Detection of Staphylococcal Exotoxins in Antrochoanal Polyps and Chronic Rhinosinusitis with Nasal Polyps. Otolaryngol Head Neck Surg 2012; 148:302-7. [DOI: 10.1177/0194599812465586] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective Staphylococcal exotoxins have been reported in the pathogenesis of many chronic inflammatory diseases. Recent reports have hypothesized that staphylococcal exotoxins might be related to inflammatory mucosal changes seen in chronic sinusitis with nasal polyps (CRS-NPs). Staphylococcal exotoxins have the capacity to act as superantigens (SAgs), bypassing normal antigen processing and directly stimulating a massive inflammatory response. The objective of this study was to analyze polyp tissue samples from patients with antrochoanal polyps (ACPs) and CRS-NPs for the presence of staphylococcal exotoxins. Study Design Prospective cohort study. Setting Tertiary medical center. Subjects and Methods Tissue samples were obtained from 29 patients and 16 controls. Thirteen of 29 patients had ACPs, and 16 had CRS-NPs. Specimens were analyzed for the presence of 5 staphylococcal exotoxins (SEA, SEB, SEC, SED, and toxic shock syndrome toxin–1) using enzyme-linked immunosorbent assay (ELISA). Results At least 1 toxin was detected in 7 of 13 patients with ACPs and in 13 of 16 patients with CRS-NPs, whereas it was detected in only 4 controls. There were no statistically significant differences between ACP and control groups ( P = .063). Our results showed a statistically significant association between toxin detection and patients with CRS-NPs ( P = .003). Conclusion Inflammatory triggers in ACP remain a subject of debate, and this study does not support the hypothesis that staphylococcal exotoxins may play a role in ACP ethiopathogenesis. Our research is consistent with the possibility of SAgs as etiological agents in the development of bilateral nasal polyposis.
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Affiliation(s)
- Mehmet Guven
- Ministry of Health Sakarya Training and Research Hospital, Department of Otorhinolaryngology, Sakarya, Turkey
| | - Oguz Karabay
- Department of Infectious Disease, Sakarya University Medical Faculty, Sakarya, Turkey
| | - Oznur Akidil
- Ministry of Health Sakarya Training and Research Hospital, Department of Otorhinolaryngology, Sakarya, Turkey
| | - Mahmut Sinan Yilmaz
- Ministry of Health Sakarya Training and Research Hospital, Department of Otorhinolaryngology, Sakarya, Turkey
| | - Muzaffer Yildirim
- Department of Pathology, Sakarya University Medical Faculty, Sakarya, Turkey
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Bernstein JM, Allen C, Rich G, Dryja D, Bina P, Reiser R, Ballow M, Wilding GE. Further observations on the role of Staphylococcus aureus exotoxins and IgE in the pathogenesis of nasal polyposis. Laryngoscope 2010; 121:647-55. [DOI: 10.1002/lary.21400] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Revised: 10/07/2010] [Accepted: 10/13/2010] [Indexed: 11/08/2022]
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Shin SY, Choi GS, Lee KH, Kim SW, Cho JS, Park HS. IgE response to staphylococcal enterotoxins in adenoid tissues from atopic children. Laryngoscope 2009; 119:171-5. [DOI: 10.1002/lary.20046] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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10
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Effects of Nasal Instillation of Staphylococcal Enterotoxin B on Allergic Inflammation in Mice. ACTA ACUST UNITED AC 2009. [DOI: 10.3342/kjorl-hns.2009.52.11.885] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Wang SM, Lu IH, Lin YL, Lin YS, Wu JJ, Chuang WJ, Lin MT, Liu CC. The severity of Streptococcus pyogenes infections in children is significantly associated with plasma levels of inflammatory cytokines. Diagn Microbiol Infect Dis 2008; 61:165-9. [PMID: 18296003 DOI: 10.1016/j.diagmicrobio.2008.01.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 01/09/2008] [Accepted: 01/11/2008] [Indexed: 11/19/2022]
Abstract
Cytokines are intimately involved with the innate and adaptive immune response to bacterial infections. This study was designed to determine the expression of inflammatory cytokines in children by the severity of Streptococcus pyogenes (group A Streptococcus [GAS]) infections. The study population consisted of 16 invasive, 20 noninvasive, and 24 pharyngeal colonization, and 21 healthy controls. All children underwent the laboratory tests and cytokine measurement. GAS isolates were analyzed for emm gene typing. Patients with invasive GAS diseases had significantly higher interferon (IFN)-gamma, interleukin (IL)-1beta, IL-6, IL-8, IL-10, and IL-18 than those with noninvasive diseases, colonization, and healthy controls. There was no difference in tumor necrosis factor (TNF)-alpha, IL-12, and IL-2 levels among the groups. Elevated white blood cell counts and levels of C-reactive protein and C3 were detected only in patients with invasive diseases. emm1 and emm12 predominated in invasive disease and colonization. Children with invasive GAS infections exhibited significant up-regulation of plasma levels of IFN-gamma, IL-1beta, IL-6, IL-8, IL-10, and IL-18, and suppression of TNF-alpha and IL-12 during the acute phase of their illness. An exuberant cytokine response was associated with the severity of illness.
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Affiliation(s)
- Shih-Min Wang
- Department of Emergency Medicine, National Cheng Kung University Medical College and Hospital, Tainan, Taiwan
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12
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Loizon S, Boeuf P, Tetteh JKA, Goka B, Obeng-Adjei G, Kurtzhals JAL, Rogier C, Akanmori BD, Mercereau-Puijalon O, Hviid L, Behr C. Vβ profiles in African children with acute cerebral or uncomplicated malaria: very focused changes among a remarkable global stability. Microbes Infect 2007; 9:1252-9. [PMID: 17890120 DOI: 10.1016/j.micinf.2007.05.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Revised: 04/30/2007] [Accepted: 05/14/2007] [Indexed: 11/18/2022]
Abstract
T cells are thought to play a critical role in cerebral malaria pathogenesis. However, available evidences are restricted to rodent models in which V beta specific T cell expansion has been associated with neurological syndrome suggesting involvement of superantigens or dominant antigens. Using flow cytometry, we studied the peripheral V beta T cell repertoire of Ghanaian children with cerebral malaria, uncomplicated malaria and asymptomatic control children, to look for either expansion or deletion of specific V beta associated with cerebral malaria. At admission, the general pattern of the repertoire of the patients was very similar, with no major distortion compared to the control group a part a significant increase of the frequency of the V beta 21.3 subset correlating with disease severity and attributed to the CD4 subset. During convalescence very limited fluctuations were observed including a significant decrease of the V beta 21.3 subset and increase of the V beta 20 subset, a subset not detected at admission. The remarkable stability of the V beta repertoire observed in acute malaria either cerebral or uncomplicated argues against the idea that cerebral malaria would result from a T cell-mediated inflammatory shock syndrome driven by some dominant super-antigenic activity(ies). The significance of the reproducible increase of the CD4+V beta 21.3T cell subset deserves further investigations.
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Affiliation(s)
- Séverine Loizon
- Unité d'Immunologie Moléculaire des Parasites, CNRS URA 2581, Département de Parasitologie, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris cedex 15, France
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Nooh MM, El-Gengehi N, Kansal R, David CS, Kotb M. HLA Transgenic Mice Provide Evidence for a Direct and Dominant Role of HLA Class II Variation in Modulating the Severity of Streptococcal Sepsis. THE JOURNAL OF IMMUNOLOGY 2007; 178:3076-83. [PMID: 17312154 DOI: 10.4049/jimmunol.178.5.3076] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Our epidemiologic studies on invasive Group A Streptococci (GAS) infections identified specific HLA class II haplotypes/alleles conferring high-risk or protection from streptococcal toxic shock syndrome with a strong protection conferred by the DRB1*15/DQB1*06 haplotype. We used HLA-transgenic mice to provide an in vitro and in vivo validation for the direct role of HLA class II allelic variation in streptococcal toxic shock syndrome. When splenocytes from mice expressing the protective HLA-DQB1*06 (DQ6) allele were stimulated with a mixture of streptococcal superantigens (SAgs), secreted by the prevalent M1T1 strain, both proliferative and cytokine responses were significantly lower than those of splenocytes from mice expressing the neutral DRB1*0402/DQB1*0302 (DR4/DQ8) alleles (p < 0.001). In crisscross experiments, the presentation of SAgs to pure T cells from either the DQ6 or the DR4/DQ8 mice resulted in significantly different levels of response depending on the HLA type expressed on the APCs. Presentation by HLA-DQ6 APCs elicited significantly lower responses than the presentation by HLA-DR4/DQ8 APCs. Our in vitro data were supported by in vivo findings, as the DQ6 mice showed significantly longer survival post-i.v. infection with live M1T1 GAS (p < 0.001) and lower inflammatory cytokine responses as compared with the DR4/DQ8 mice (p < 0.01). The data presented here provide evidence for a direct role of HLA class II molecules in modulating responses to GAS SAgs and underscore the dominant role of HLA class II allelic variation in potentiating the severity of GAS systemic infections.
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Affiliation(s)
- Mohammed M Nooh
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Neutralization of staphylococcal exotoxins in vitro by human-origin intravenous immunoglobulin. J Infect Chemother 2007; 13:368-72. [DOI: 10.1007/s10156-007-0551-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Accepted: 07/11/2007] [Indexed: 10/22/2022]
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Goldmann O, Lengeling A, Böse J, Bloecker H, Geffers R, Chhatwal GS, Medina E. The role of the MHC on resistance to group a streptococci in mice. THE JOURNAL OF IMMUNOLOGY 2005; 175:3862-72. [PMID: 16148132 DOI: 10.4049/jimmunol.175.6.3862] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The severity of infection with Streptococcus pyogenes is strongly influenced by the host's genetics. This observation extends to the murine model of streptococcal infection, where the background of the mouse strain determines the infection outcome (BALB/c are resistant, whereas C3H/HeN are susceptible). To determine the extent to which the MHC complex (H2) contributed to diseases susceptibility, the response to S. pyogenes of congenic BALB mice from a resistant background (BALB/c), but carrying the H2(k) region of susceptible C3H/HeN mice (BALB/k), was examined. BALB/k were as susceptible as the H2 donor strain (C3H/HeN). Linkage analysis performed in F(2) backcross ([BALB/c x C3H/HeN] x BALB/c) mice confirmed the presence of a susceptibility locus within the H2 region on proximal chromosome 17. The possibility that modulation of T cell responses to streptococcal superantigens (GAS-SAgs) by different H2 haplotypes may influence disease severity was examined. BALB/k exhibited a significantly stronger response at the level of cell proliferation and cytokine production to GAS-SAgs than did BALB/c mice. However, the fact that T cell-deficient SCID-C3H/HeN mice also exhibited a susceptible phenotype suggests a more important contribution of innate effector cells to disease susceptibility. Lower transcriptional levels of certain inflammation-related regulatory genes located on chromosome 17 were detected in macrophages from susceptible than in those from resistant mice in response to infection. These results suggest that susceptibility to S. pyogenes may be associated with an altered transcription of specific genes that may compromise the endogenous regulatory processes controlling the inflammatory cascade and favor the progression to sepsis.
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Affiliation(s)
- Oliver Goldmann
- Infection Immunology Group, Gesellschaft fur Biotechnologishe Forschung-German Research Center for Biotechnology, Braunschweig, Germany
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Mack KD, Von Goetz M, Lin M, Venegas M, Barnhart J, Lu Y, Lamar B, Stull R, Silvin C, Owings P, Bih FY, Abo A. Functional identification of kinases essential for T-cell activation through a genetic suppression screen. Immunol Lett 2005; 96:129-45. [PMID: 15585316 DOI: 10.1016/j.imlet.2004.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2004] [Revised: 08/14/2004] [Accepted: 08/15/2004] [Indexed: 01/18/2023]
Abstract
Activation of T-cells by antigens initiates a complex series of signal-transduction events that are critical for immune responses. While kinases are key mediators of signal transduction networks, several of which have been well characterized in T-cell activation, the functional roles of other kinases remain poorly defined. To address this deficiency, we developed a genetic screen to survey the functional roles of kinases in antigen mediated T-cell activation. A retroviral library was constructed that expressed genetic suppressor elements (GSEs) comprised of peptides and antisense nucleotides derived from kinase cDNAs including members of the STE, CAMK, AGC, CMGC, RGC, TK, TKL, Atypical, and Lipid kinase groups. The retroviral library was expressed in Jurkat T-cells and analyzed for their effect on T-cell activation as monitored by CD69 expression. Jurkat cells were activated by antigen presenting cells treated with superantigen, and sorted for a CD69 negative phenotype by flow cytometry. We identified 19 protein kinases that were previously implicated in T-cell signaling processes and 12 kinases that were not previously linked to T-cell activation. To further validate our approach, we characterized the role of the protein kinase MAP4K4 that was identified in the screen. siRNA studies showed a role for MAP4K4 in antigen mediated T-cell responses in Jurkat and primary T-cells. In addition, by analyzing multiple promoter elements using reporter assays, we have shown that MAP4K4 is implicated in the activation of the TNF-alpha promoter. Our results suggest that this methodology could be used to survey the function of the entire kinome in T-cell activation.
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Affiliation(s)
- Karl D Mack
- PPD Discovery Inc., 1505 O'Brien Drive, Menlo Park, CA 94025, USA.
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Perpoint T, Lina G, Poyart C, de Barbeyrac B, Traineau R, Jeanne M, Vandenesch F, Etienne J. Two Cases of Fatal Shock after Transfusion of Platelets Contaminated by Staphylococcus aureus: Role of Superantigenic Toxins. Clin Infect Dis 2004; 39:e106-9. [PMID: 15546071 DOI: 10.1086/425499] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Accepted: 07/14/2004] [Indexed: 11/03/2022] Open
Abstract
We detected Staphylococcus aureus superantigenic toxins in the platelet infusion bags that had been used for 2 patients who subsequently developed transfusion-associated Staphylococcus aureus infection. Both patients, who were immunodeficient, developed manifestations of toxic shock syndrome and septic shock, and they died soon after the onset of infection.
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Affiliation(s)
- Thomas Perpoint
- Centre National de Référence des Staphylocoques, INSERM E0230, Institute Fédératif de Recherche 62, Lyon, France
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Baker HM, Proft T, Webb PD, Arcus VL, Fraser JD, Baker EN. Crystallographic and Mutational Data Show That the Streptococcal Pyrogenic Exotoxin J Can Use a Common Binding Surface for T-cell Receptor Binding and Dimerization. J Biol Chem 2004; 279:38571-6. [PMID: 15247241 DOI: 10.1074/jbc.m406695200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The protein toxins known as superantigens (SAgs), which are expressed primarily by the pathogenic bacteria Staphylococcus aureus and Streptococcus pyogenes, are highly potent immunotoxins with the ability to cause serious human disease. These SAgs share a conserved fold but quite varied activities. In addition to their common role of cross-linking T-cell receptors (TCRs) and major histocompatibility complex class II (MHC-II) molecules, some SAgs can cross-link MHC-II, using diverse mechanisms. The crystal structure of the streptococcal superantigen streptococcal pyrogenic exotoxin J (SPE-J) has been solved at 1.75 A resolution (R = 0.209, R(free) = 0.240), both with and without bound Zn(2+). The structure displays the canonical two-domain SAg fold and a zinc-binding site that is shared by a subset of other SAgs. Most importantly, in concentrated solution and in the crystal, SPE-J forms dimers. These dimers, which are present in two different crystal environments, form via the same face that is used for TCR binding in other SAgs. Site-directed mutagenesis shows that this face is also used for TCR binding SPE-J. We infer that SPE-J cross-links TCR and MHC-II as a monomer but that dimers may form on the antigen-presenting cell surface, cross-linking MHC-II and eliciting intracellular signaling.
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Affiliation(s)
- Heather M Baker
- School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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Proft T, Sriskandan S, Yang L, Fraser JD. Superantigens and streptococcal toxic shock syndrome. Emerg Infect Dis 2004; 9:1211-8. [PMID: 14609454 PMCID: PMC3033064 DOI: 10.3201/eid0910.030042] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
| | | | - Lily Yang
- University of Auckland, Auckland, New Zealand
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20
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Ribeiro-Dias F, Shio MT, Timenetsky J, Oliane APC, Metran CC, Pessoa FB, Jancar S. Mycoplasma arthritidis superantigen (MAM)-induced macrophage nitric oxide release is MHC class II restricted, interferongamma dependent, and toll-like receptor 4 independent. Exp Cell Res 2003; 286:345-54. [PMID: 12749862 DOI: 10.1016/s0014-4827(03)00108-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Mycoplasma arthritidis causes arthritis in rodents that resembles human rheumatoid arthritis. It produces a superantigen (MAM) that stimulates production of cytokines by making a bridge between lymphocyte T-cell receptor with the appropriate Vbeta chain, and H-2 1-Ealpha MHC class II molecules. Here we studied MAM-induced nitric oxide (NO) production in mouse peritoneal macrophages and found that it was: (1) time and concentration dependent, (2) possibly derived from inducible NOS synthase since it was reduced significantly by amino guanidine pretreatment, (3) restricted to H-2(K) (C3H/HePas and C3H/HeJ) and H-2(d) strains (BALB/c), (4) independent of TLR4 signaling since the coisogenic strains C3H/HePas and C3H/HeJ (TLR4 deficient) produced similar levels of NO following MAM stimulation, (5) potentiated by lipopolysaccharide, and (6) dependent on the presence of nonadherent peritoneal cells. Neutralization of interferon-gamma (IFNgamma in the peritoneal cell cultures with monoclonal antibodies abolished MAM-induced NO production. Addition of rIFNgamma to the adherent cells substituted the nonadherent cells for MAM-induced NO production. A macrophage cell line, J774A.1 (H-2(d)), also produced NO upon MAM stimulation but only when BALB/c spleen lymphocytes were added. Thus, in murine macrophages, MAM induces NO production that is dependent on signaling through MHC class II molecules and IFNgamma but independent of TLR4 expression.
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MESH Headings
- Animals
- Antigens
- Antigens, Bacterial
- Arthritis, Rheumatoid/immunology
- Arthritis, Rheumatoid/metabolism
- Cell Communication/immunology
- Cells, Cultured
- Disease Models, Animal
- Dose-Response Relationship, Drug
- Histocompatibility Antigens Class II/drug effects
- Histocompatibility Antigens Class II/metabolism
- Interferon-gamma/metabolism
- Interferon-gamma/pharmacology
- Lymphocyte Activation/drug effects
- Lymphocyte Activation/immunology
- Lymphocytes/immunology
- Lymphocytes/metabolism
- Macrophages/drug effects
- Macrophages/metabolism
- Male
- Membrane Glycoproteins/drug effects
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C3H
- Mice, Inbred C57BL
- Mitogens/pharmacology
- Nitric Oxide/biosynthesis
- Nitric Oxide Synthase/drug effects
- Nitric Oxide Synthase/metabolism
- Proteins
- Receptors, Cell Surface/drug effects
- Receptors, Cell Surface/metabolism
- Signal Transduction/drug effects
- Signal Transduction/immunology
- Superantigens
- Toll-Like Receptor 4
- Toll-Like Receptors
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Affiliation(s)
- Fátima Ribeiro-Dias
- Immunology Section/DMIPP/IPTSP, Federal University of Goiás, Goiânia, Brazil
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21
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Proft T, Webb PD, Handley V, Fraser JD. Two novel superantigens found in both group A and group C Streptococcus. Infect Immun 2003; 71:1361-9. [PMID: 12595453 PMCID: PMC148831 DOI: 10.1128/iai.71.3.1361-1369.2003] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Two novel streptococcal superantigen genes (speL(Se) and speM(Se)) were identified from the Streptococcus equi genome database at the Sanger Center. Genotyping of 8 S. equi isolates and 40 Streptococcus pyogenes isolates resulted in the detection of the orthologous genes speL and speM in a restricted number of S. pyogenes isolates (15 and 5%, respectively). Surprisingly, the novel superantigen genes could not be found in any of the analyzed S. equi isolates. The results suggest that both genes are located on a mobile element that enables gene transfer between individual isolates and between streptococci from different Lancefield groups. S. equi pyrogenic exotoxin L (SPE-L(Se))/streptococcal pyrogenic exotoxin L (SPE-L) and SPE-M(Se)/SPE-M are most closely related to SMEZ, SPE-C, SPE-G, and SPE-J, but build a separate branch within this group. Recombinant SPE-L (rSPE-L) and rSPE-M were highly mitogenic for human peripheral blood lymphocytes, with half-maximum responses at 1 and 10 pg/ml, respectively. The results from competitive binding experiments suggest that both proteins bind major histocompatibility complex class II at the beta-chain, but not at the alpha-chain. The most common targets for both toxins were human Vbeta1.1 expressing T cells. Seroconversion against SPE-L and SPE-M was observed in healthy blood donors, suggesting that the toxins are expressed in vivo. Interestingly, the speL gene is highly associated with S. pyogenes M89, a serotype that is linked to acute rheumatic fever in New Zealand.
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Affiliation(s)
- Thomas Proft
- Department of Molecular Medicine and Pathology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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22
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Hodges E, Krishna MT, Pickard C, Smith JL. Diagnostic role of tests for T cell receptor (TCR) genes. J Clin Pathol 2003; 56:1-11. [PMID: 12499424 PMCID: PMC1769865 DOI: 10.1136/jcp.56.1.1] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Rapid advances in molecular biological techniques have made it possible to study disease pathogenesis at a genomic level. T cell receptor (TCR) gene rearrangement is an important event in T cell ontogeny that enables T cells to recognise antigens specifically, and any dysregulation in this complex yet highly regulated process may result in disease. Using techniques such as Southern blot hybridisation, polymerase chain reaction, and flow cytometry it has been possible to characterise T cell proliferations in malignancy and in diseases where T cells have been implicated in the pathogenesis. The main aim of this article is to discuss briefly the process of TCR gene rearrangement and highlight the disorders in which expansions or clonal proliferations of T cells have been recognised. It will also describe various methods that are currently used to study T cell populations in body fluids and tissue, their diagnostic role, and current limitations of the methodology.
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Affiliation(s)
- E Hodges
- Wessex Immunology, Southampton University Hospitals NHS Trust, Tremona Road, Southampton SO16 6YD, UK.
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23
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Arcus VL, Langley R, Proft T, Fraser JD, Baker EN. The Three-dimensional structure of a superantigen-like protein, SET3, from a pathogenicity island of the Staphylococcus aureus genome. J Biol Chem 2002; 277:32274-81. [PMID: 12082105 DOI: 10.1074/jbc.m203914200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The staphylococcal enterotoxin-like toxins (SETs) are a family of proteins encoded within the Staphylococcus aureus genome that were identified by their similarity to the well described bacterial superantigens. The first crystal structure of a member of the SET family, SET3, has been determined to 1.9 A (R = 0.205, R(free) = 0.240) and reveals a fold characteristic of the superantigen family but with significant differences. The SET proteins are secreted at varying levels by staphylococcal isolates, and seroconversion studies of normal individuals indicate that they are strongly antigenic to humans. Recombinant SETs do not exhibit any of the properties expected of superantigens such as major histocompatibility complex class II binding or broad T-cell activation, suggesting they have an entirely different function. The fact that the whole gene family is clustered within the pathogenicity island SaIn2 of the S. aureus genome suggests that they are involved in host/pathogen interactions.
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Affiliation(s)
- Vickery L Arcus
- School of Biological Sciences, University of Auckland, Private Bag 92-019 Auckland, New Zealand
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24
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Kamel NS, Banks MC, Dosik A, Ursea D, Yarilina AA, Posnett DN. Lack of muco-cutaneous signs of toxic shock syndrome when T cells are absent: S. aureus shock in immunodeficient adults with multiple myeloma. Clin Exp Immunol 2002; 128:131-9. [PMID: 12033193 PMCID: PMC1906360 DOI: 10.1046/j.1365-2249.2002.01805.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2002] [Indexed: 11/20/2022] Open
Abstract
Staphylococcal toxic shock syndrome (TSS) is an acute life threatening disease. The diagnosis can be made clinically based on diagnostic criteria. The clinical manifestations are caused in large part by there lease of high levels of T-cell-derived cytokines as a result of potent toxins, also called superantigens (SAg), produced by Staphylococcus aureus, but it is not clear which clinical symptoms/signs are strictly T-cell dependent. Here, we report on three adults with multiple myeloma (MM) presenting with S.aureus sepsis/shock, and two patients with typical TSS. The MM patients had compromised humoral immunity because of depression of normal immunoglobulin (Ig) levels at the expense of the M protein. In addition, their T cells were absent due to high dose chemotherapy initiated for bone marrow trans-plantation. The MM cases lacked mucosal hyperemia, erythroderma and desquamation, but were otherwise indistinguishable from the TSS cases. All patients grew S. aureus and in each case, SAg genes were detected by PCR. In several cases, the plasma contained biological SAg activity resulting in VP specific proliferation of indicator T cells in vitro. The same specific activity was observed with the supernatant fluids of S. aureus broth cultures from the respective bacterial isolates. This confirms the presence of bio-active toxins in the plasma but did not lead to full blown TSS when T cells were lacking.Thus, S. aureus sepsis/shock can be clinically distinguished from typical TSS, and we suggest that mucocutaneous manifestations of TSS are the most telling signs of massive T-cell-dependent cytokine release.
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Affiliation(s)
- N S Kamel
- Department of Medicine, Weill Medical College, Cornell University, New York, NY 10021, USA
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25
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Llewelyn M, Cohen J. Superantigens: microbial agents that corrupt immunity. THE LANCET. INFECTIOUS DISEASES 2002; 2:156-62. [PMID: 11944185 DOI: 10.1016/s1473-3099(02)00222-0] [Citation(s) in RCA: 200] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Microbial superantigens are a family of protein exotoxins that share the ability to trigger excessive and aberrant activation of T cells. The best characterised are the staphylococcal enterotoxins and the streptococcal pyrogenic exotoxins that trigger the staphylococcal and streptococcal toxic shock syndromes. It is now apparent that superantigens have a wider role in the pathology of infectious diseases than has previously been appreciated. Staphylococcus aureus and Streptococcus pyogenes together produce 19 different superantigens. The range of microorganisms known to produce superantigens has expanded to include Gram negative bacteria, mycoplasma, and viruses. Research is beginning to shed light on the more subtle parts these molecules play in causing disease and to produce some real possibilities for specific treatment of superantigen-induced toxicity. We aim to highlight these new developments and review the science behind these fascinating molecules.
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Affiliation(s)
- Martin Llewelyn
- Department of Infectious Diseases, Hammersmith Hospital, Du Cane Road, London W12 0NN, UK.
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26
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Tikhonov I, Kitabwalla M, Wallace M, Malkovsky M, Volkman B, Pauza CD. Staphylococcal superantigens induce lymphotactin production by human CD4+ and CD8+ T cells. Cytokine 2001; 16:73-8. [PMID: 11683588 DOI: 10.1006/cyto.2001.0944] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Lymphotactin is a potent chemotactic cytokine (chemokine) that is produced by and also attracts T and natural killer (NK) cells. We are studying whether chemokines that affect mainly T cells might also regulate immune responses by preferentially recruiting individual subsets or by affecting cytokine or other chemokine responses. In order to pursue these questions, we need to learn more about the mechanisms regulating lymphotactin production and the cell types capable of releasing this factor. We used new monoclonal antibodies against human lymphotactin to develop a sensitive antigen-capture enzyme linked immunoabsorbent assay (ELISA) that measures chemokine levels in culture fluids. Using this capture ELISA, we showed that lymphotactin could be produced by CD4+ and CD8+ T cells, but only after T cell-receptor-dependent stimulation using bacterial superantigens and not after treatment by inflammatory cytokines or lipopolysaccharide (LPS). Our data show that lymphotactin production responds mainly to T cell-receptor signals in CD4+ and CD8+ T cells, and suggests a mechanism whereby this chemokine could help to regulate T cell immune responses.
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Affiliation(s)
- I Tikhonov
- Institute of Human Virology, 725 W. Lombard St, Baltimore, MD 21201, USA
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27
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Unnikrishnan M, Cohen J, Sriskandan S. Complementation of a speA negative Streptococcus pyogenes with speA: effects on virulence and production of streptococcal pyrogenic exotoxin A. Microb Pathog 2001; 31:109-14. [PMID: 11500096 DOI: 10.1006/mpat.2001.0453] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have shown previously that an isogenic SPEA-negative Streptococcus pyogenes strain did not attenuate virulence in a murine model of necrotizing fasciitis. The aim of this study was to confirm that streptococcal pyrogenic exotoxin A (SPEA) is not crucial for streptococcal invasiveness in murine invasive infection. The SPEA-negative S. pyogenes (H326) was complemented with speA extra-chromosomally to create strain H361 which produced 2.2-fold more SPEA compared with the parental speA(+)wild-type (H305). The growth phase-regulated expression of SPEA in vitro was unaffected in this strain. Complementation with speA resulted in reduced virulence and bacterial counts in invasive murine infection. SPEA production was quantitated from muscle tissue of infected mice. However, H361 did not produce more SPEA than H305 in vivo. We conclude that SPEA does not play a key role in invasive murine streptococcal infection.
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Affiliation(s)
- M Unnikrishnan
- Department of Infectious Diseases, Imperial College School of Medicine, Hammersmith Hospital, Du Can Road, London W12 0NN, UK
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28
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Tikhonov I, Doroshenko T, Chaly Y, Smolnikova V, Pauza CD, Voitenok N. Down-regulation of CXCR1 and CXCR2 expression on human neutrophils upon activation of whole blood by S. aureus is mediated by TNF-alpha. Clin Exp Immunol 2001; 125:414-22. [PMID: 11531949 PMCID: PMC1906137 DOI: 10.1046/j.1365-2249.2001.01626.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2001] [Indexed: 11/20/2022] Open
Abstract
It was suggested that bacterial products can inhibit the expression of leucocyte chemokine receptors during sepsis and affect leucocyte functions in septic syndrome. Superantigens and toxins produced by Staphylococcus aureus are capable of activating leucocytes via binding to MHC-II antigens on monocytes and T-cell receptor molecules on T lymphocytes. It was recently shown that staphylococcal enterotoxins directly down-regulate the expression of CC chemokine receptors on monocytes through binding to MHC class II molecules. We studied the effects of killed S. aureus on the expression of interleukin-8 receptors, CXCR1 and CXCR2, on polymorphonuclear leucocytes (PMN), which are known to lack the expression of MHC-II antigens. It was shown that S. aureus down-regulated the cell-surface expression of CXCR1 and CXCR2 on PMN in the whole blood and total blood leucocyte fraction containing PMN and monocytes, but did not modulate IL-8 receptor expression in purified PMN suspension. Antibody to TNF-alpha abrogated down-regulation of IL-8 receptors induced by S. aureus. In contrast, LPS reduced CXCR1 and CXCR2 expression in purified PMN and whole blood in a TNF-alpha-independent manner. We further showed that TNF-alpha-induced decrease of CXCR1 and CXCR2 expression was associated with lower IL-8 binding and lower CXCR1 and CXCR2 mRNA levels, and was abrogated by protease inhibitors. We suggest that during septicemia, S. aureus may inhibit neutrophil responsiveness to IL-8 and other CXC chemokines via TNF-alpha- mediated down-regulation of CXCR1 and CXCR2.
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Affiliation(s)
- I Tikhonov
- Laboratory of Cellular and Molecular Immunology, Institute of Hematology and Blood Transfusion, Minsk, Belarus.
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29
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Proft T, Arcus VL, Handley V, Baker EN, Fraser JD. Immunological and biochemical characterization of streptococcal pyrogenic exotoxins I and J (SPE-I and SPE-J) from Streptococcus pyogenes. THE JOURNAL OF IMMUNOLOGY 2001; 166:6711-9. [PMID: 11359827 DOI: 10.4049/jimmunol.166.11.6711] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Recently, we described the identification of novel streptococcal superantigens (SAgs) by mining the Streptococcus pyogenes M1 genome database at Oklahoma University. Here, we report the cloning, expression, and functional analysis of streptococcal pyrogenic exotoxin (SPE)-J and another novel SAg (SPE-I). SPE-I is most closely related to SPE-H and staphylococcal enterotoxin I, whereas SPE-J is most closely related to SPE-C. Recombinant forms of SPE-I and SPE-J were mitogenic for PBL, both reaching half maximum responses at 0.1 pg/ml. Evidence from binding studies and cell aggregation assays using a human B-lymphoblastoid cell line (LG-2) suggests that both toxins exclusively bind to the polymorphic MHC class II beta-chain in a zinc-dependent mode but not to the generic MHC class II alpha-chain. The results from analysis by light scattering indicate that SPE-J exists as a dimer in solution above concentrations of 4.0 mg/ml. Moreover, SPE-J induced a rapid homotypic aggregation of LG-2 cells, suggesting that this toxin might cross-link MHC class II molecules on the cell surface by building tetramers of the type HLA-DRbeta-SPE-J-SPE-J-HLA-DRbeta. SPE-I preferably stimulates T cells bearing the Vbeta18.1 TCR, which is not targeted by any other known SAG: SPE-J almost exclusively stimulates Vbeta2.1 T cells, a Vbeta that is targeted by several other streptococcal SAgs, suggesting a specific role for this T cell subpopulation in immune defense. Despite a primary sequence diversity of 51%, SPE-J is functionally indistinguishable from SPE-C and might play a role in streptococcal disease, which has previously been addressed to SPE-C.
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Affiliation(s)
- T Proft
- Division of Molecular Medicine and School of Biological Sciences, University of Auckland, Auckland, New Zealand
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30
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Uncovering the Differences between T Cell Tolerance and Immunity. Autoimmunity 2001. [DOI: 10.1007/978-94-010-0981-2_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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32
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Rago C, Tocce K, Ficarro S, Masters G, Riggs J. Superantigen disruption of CD8+ T and B lymphocyte homeostasis. Immunobiology 2000; 202:508-18. [PMID: 11205378 DOI: 10.1016/s0171-2985(00)80107-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Superantigens (SAgs) activate TH cells and induce their differentiation into cytokine-producing effector cells. Supranormal cytokine production is characteristic of SAg-induced polyclonal TH activation. Study of this interaction has focused upon TH cell function to the relative exclusion of other lymphocyte populations. SAgs also impact cells dependent upon TH cells for their differentiation and disrupt the normal homeostasis of the immune system. In this report, several changes in lymphocyte biology that result from SAg activation of TH cells are described. SCID mice, reconstituted with the SAg-expressing cells of DBA/2J mice, were employed as secondary recipients of SAg-reactive TH cells. Significant increases in serum IgM and IgG2a production were noted after the transfer of SAg-reactive It cells. Both B and CD8 T lymphocyte numbers increased with those of CD8 T cells surpassing levels found in normal mice. These results illustrate the ability of the TH-SAg interaction to disrupt B and CD8+ T lymphocyte homeostasis.
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Affiliation(s)
- C Rago
- Department of Biology, Rider University, Lawrenceville, NJ 08648-3099, USA
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33
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Abstract
OBJECTIVE To analyze the implications for therapeutic advances in the treatment of sepsis and septic shock based on the mechanisms underlying the response to microbial infection. DATA SOURCES Clinical trials and experimental models designed to determine the key mechanisms involved in cellular and molecular processes of inflammatory reactions. STUDY SELECTION Analyses of normal immune reactions to microbial infection, processes involved in the development of sepsis, and reasons for frequent failure of regimens based on current therapeutic rationales. DATA EXTRACTION/SYNTHESIS Review of the data suggests that the dysregulation of the immune system resulting in sepsis/septic shock is ineffectually blocked by interfering with the action of inflammatory mediators or cascades, as these processes may be too complex to be easily antagonized. Rather, blockade of the action of microbial products or of the intracellular processes activated by receptor interaction with these products may provide a more promising therapeutic alternative. CONCLUSIONS The sepsis syndrome induced by microbial pathogens reflects excessive stimulation of the processes of innate immunity. Bacterial components reacting with specific receptors activate intracellular processes, resulting in the release of excessive amounts of mediators of inflammation as well as triggering multiple complex proteolytic cascades. Blockade or antagonism of the actions of individual intermediary messenger molecules has proved therapeutically unsuccessful, because blockade of mediators alone does not block the direct activation of processes such as coagulation and complement. The dysregulation that characterizes sepsis may be amenable to blockade of the bacterial components or to the intracellular pathways triggered by these products.
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Affiliation(s)
- M P Glauser
- Department of Internal Medicine, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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34
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Churchill HR, Andersen PS, Parke EA, Mariuzza RA, Kranz DM. Mapping the energy of superantigen Staphylococcus enterotoxin C3 recognition of an alpha/beta T cell receptor using alanine scanning mutagenesis. J Exp Med 2000; 191:835-46. [PMID: 10704464 PMCID: PMC2195847 DOI: 10.1084/jem.191.5.835] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Accepted: 01/27/2000] [Indexed: 11/04/2022] Open
Abstract
Binding of the T cell receptor (TCR) to a bacterial superantigen (SAG) results in stimulation of a large population of T cells and subsequent inflammatory reactions. To define the functional contribution of TCR residues to SAG recognition, binding by 24 single-site alanine substitutions in the TCR Vbeta domain to Staphylococcus aureus enterotoxin (SE) C3 was measured, producing an energy map of the TCR-SAG interaction. The results showed that complementarity determining region 2 (CDR2) of the Vbeta contributed the majority of binding energy, whereas hypervariable region 4 (HV4) and framework region 3 (FR3) contributed a minimal amount of energy. The crystal structure of the Vbeta8.2-SEC3 complex suggests that the CDR2 mutations act by disrupting Vbeta main chain interactions with SEC3, perhaps by affecting the conformation of CDR2. The finding that single Vbeta side chain substitutions had significant effects on binding and that other SEC3-reactive Vbeta are diverse at these same positions indicates that SEC3 binds to other TCRs through compensatory mechanisms. Thus, there appears to be strong selective pressure on SAGs to maintain binding to diverse T cells.
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MESH Headings
- Alanine/genetics
- Animals
- Binding Sites
- Enterotoxins/immunology
- Enterotoxins/metabolism
- Humans
- Mice
- Models, Molecular
- Mutagenesis
- Protein Binding
- Receptors, Antigen, T-Cell, alpha-beta/chemistry
- Receptors, Antigen, T-Cell, alpha-beta/genetics
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Staphylococcus aureus/immunology
- Superantigens/immunology
- Superantigens/metabolism
- Thermodynamics
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Affiliation(s)
| | - Peter S. Andersen
- Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, Maryland 20850
| | - Evan A. Parke
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801
| | - Roy A. Mariuzza
- Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, Maryland 20850
| | - David M. Kranz
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801
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