1
|
Cranmer KD, Pant MD, Quesnel S, Sharp JA. Clonal Diversity, Antibiotic Resistance, and Virulence Factor Prevalence of Community Associated Staphylococcus aureus in Southeastern Virginia. Pathogens 2023; 13:25. [PMID: 38251333 PMCID: PMC10821353 DOI: 10.3390/pathogens13010025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 01/23/2024] Open
Abstract
Staphylococcus aureus is a significant human pathogen with a formidable propensity for antibiotic resistance. Worldwide, it is the leading cause of skin and soft tissue infections (SSTI), septic arthritis, osteomyelitis, and infective endocarditis originating from both community- and healthcare-associated settings. Although often grouped by methicillin resistance, both methicillin-resistant (MRSA) and methicillin-sensitive (MSSA) strains are known to cause significant pathologies and injuries. Virulence factors and growing resistance to antibiotics play major roles in the pathogenicity of community-associated strains. In our study, we examined the genetic variability and acquired antibiograms of 122 S. aureus clinical isolates from SSTI, blood, and urinary tract infections originating from pediatric patients within the southeast region of Virginia, USA. We identified a suite of clinically relevant virulence factors and evaluated their prevalence within these isolates. Five genes (clfA, spA, sbi, scpA, and vwb) with immune-evasive functions were identified in all isolates. MRSA isolates had a greater propensity to be resistant to more antibiotics as well as significantly more likely to carry several virulence factors compared to MSSA strains. Further, the carriage of various genes was found to vary significantly based on the infection type (SSTI, blood, urine).
Collapse
Affiliation(s)
- Katelyn D. Cranmer
- Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Mohan D. Pant
- School of Health Professions, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| | - Suzanne Quesnel
- Children’s Hospital of the King’s Daughters, Norfolk, VA 23507, USA
| | - Julia A. Sharp
- Microbiology and Molecular Cell Biology, Eastern Virginia Medical School, Norfolk, VA 23507, USA
- School of Health Professions, Eastern Virginia Medical School, Norfolk, VA 23507, USA
| |
Collapse
|
2
|
Berry SC, Triplett OA, Yu LR, Hart ME, Jackson LS, Tolleson WH. Microcalorimetric Investigations of Reversible Staphylococcal Enterotoxin Unfolding. Toxins (Basel) 2022; 14:toxins14080554. [PMID: 36006217 PMCID: PMC9414061 DOI: 10.3390/toxins14080554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 07/27/2022] [Accepted: 08/04/2022] [Indexed: 11/24/2022] Open
Abstract
Staphylococcal food poisoning (SFP) is a common food-borne illness often associated with contamination during food handling. The genes for Staphylococcal enterotoxin (SE) isoforms SEA and SEB are frequently detected in human nasal Staphylococcus aureus isolates and these toxins are commonly associated with SFP. Past studies described the resistance of preformed SE proteins to heat inactivation and their reactivation upon cooling in foods. Full thermodynamic analyses for these processes have not been reported, however. The thermal stabilities of SEA, SEB, and SEH and reversibility of unfolding in simple buffers were investigated at pH 4.5 and pH 6.8 using differential scanning calorimetry (DSC). SEA and SEB unfolding was irreversible at pH 6.8 and at least partially reversible at pH 4.5 while SEH unfolding was irreversible at pH 4.5 and reversible at pH 6.8. Additional studies showed maximum refolding for SEB at pH 3.5–4.0 and diminished refolding at pH 4.5 with increasing ionic strength. SE-stimulated secretion of interferon-gamma by human peripheral blood mononuclear cells was used to assess residual SE biological activity following heat treatments using conditions matching those used for DSC studies. The biological activities of SEB and SEH exhibited greater resistance to heat inactivation than that of SEA. The residual activities of heat-treated SEB and SEH were measurable but diminished further in the presence of reconstituted nonfat dry milk adjusted to pH 4.5 or pH 6.8. To different extents, the pH and ionic strengths typical for foods influenced the thermal stabilities of SEA, SEB, and SEH and their potentials to renature spontaneously after heat treatments.
Collapse
Affiliation(s)
- Susan C. Berry
- National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Odbert A. Triplett
- National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Li-Rong Yu
- National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Mark E. Hart
- National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
| | - Lauren S. Jackson
- Division of Food Processing Science & Technology, Center for Food Safety and Applied Nutrition, US Food and Drug Administration, 6502 S. Archer Rd., Bedford Park, IL 60501, USA
| | - William H. Tolleson
- National Center for Toxicological Research, US Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA
- Correspondence: or ; Tel.: +1870-543-7645
| |
Collapse
|
3
|
Shulcheva I, Shchannikova M, Melnik B, Fursova K, Semushina S, Zamyatina A, Oleinikov V, Brovko F. The zinc ions stabilize the three-dimensional structure and are required for the binding of staphylococcal enterotoxin-like protein P (SEIP) with MHC-II receptors. Protein Expr Purif 2022; 197:106098. [DOI: 10.1016/j.pep.2022.106098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 11/26/2022]
|
4
|
Uzunҫayır S, Vera‐Rodriguez A, Regenthal P, Åbacka H, Emanuelsson C, Bahl CD, Lindkvist‐Petersson K. Analyses of the complex formation of staphylococcal enterotoxin A and the human gp130 cytokine receptor. FEBS Lett 2022; 596:910-923. [DOI: 10.1002/1873-3468.14292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 12/14/2021] [Accepted: 01/10/2022] [Indexed: 11/08/2022]
Affiliation(s)
- Sibel Uzunҫayır
- Department of Experimental Medical Science Lund University BMC C13 22 184 Lund Sweden
| | - Arturo Vera‐Rodriguez
- Institute for Protein Innovation Boston USA
- Division of Hematology‐Oncology, Boston Children’s Hospital Harvard Medical School Boston USA
| | - Paulina Regenthal
- Department of Experimental Medical Science Lund University BMC C13 22 184 Lund Sweden
| | - Hannah Åbacka
- Department of Experimental Medical Science Lund University BMC C13 22 184 Lund Sweden
| | - Cecilia Emanuelsson
- Department of Chemistry Division for Biochemistry and Structural Biology Lund University Lund Sweden
| | - Christopher D. Bahl
- Institute for Protein Innovation Boston USA
- Division of Hematology‐Oncology, Boston Children’s Hospital Harvard Medical School Boston USA
| | - Karin Lindkvist‐Petersson
- Department of Experimental Medical Science Lund University BMC C13 22 184 Lund Sweden
- LINXS ‐ Lund Institute of Advanced Neutron and X‐ray Science Scheelevägen 19 SE‐223 70 Lund Sweden
| |
Collapse
|
5
|
Cadet F, Fontaine N, Vetrivel I, Ng Fuk Chong M, Savriama O, Cadet X, Charton P. Application of fourier transform and proteochemometrics principles to protein engineering. BMC Bioinformatics 2018; 19:382. [PMID: 30326841 PMCID: PMC6191906 DOI: 10.1186/s12859-018-2407-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Accepted: 10/03/2018] [Indexed: 12/13/2022] Open
Abstract
Background Connecting the dots between the protein sequence and its function is of fundamental interest for protein engineers. In-silico methods are useful in this quest especially when structural information is not available. In this study we propose a mutant library screening tool called iSAR (innovative Sequence Activity Relationship) that relies on the physicochemical properties of the amino acids, digital signal processing and partial least squares regression to uncover these sequence-function correlations. Results We show that the digitalized representation of the protein sequence in the form of a Fourier spectrum can be used as an efficient descriptor to model the sequence-activity relationship of proteins. The iSAR methodology that we have developed identifies high fitness mutants from mutant libraries relying on physicochemical properties of the amino acids, digital signal processing and regression techniques. iSAR correlates variations caused by mutations in spectra with biological activity/fitness. It takes into account the impact of mutations on the whole spectrum and does not focus on local fitness alone. The utility of the method is illustrated on 4 datasets: cytochrome P450 for thermostability, TNF-alpha for binding affinity, GLP-2 for potency and enterotoxins for thermostability. The choice of the datasets has been made such as to illustrate the ability of the method to perform when limited training data is available and also when novel mutations appear in the test set, that have not been featured in the training set. Conclusion The combination of Fast Fourier Transform and Partial Least Squares regression is efficient in capturing the effects of mutations on the function of the protein. iSAR is a fast algorithm which can be implemented with limited computational resources and can make effective predictions even if the training set is limited in size. Electronic supplementary material The online version of this article (10.1186/s12859-018-2407-8) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Frédéric Cadet
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France.
| | - Nicolas Fontaine
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| | - Iyanar Vetrivel
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| | - Matthieu Ng Fuk Chong
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| | - Olivier Savriama
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| | - Xavier Cadet
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| | - Philippe Charton
- Peaccel SAS, Protein Engineering ACCELerator, n°6 Square Albin Cachot, Box 42, 75013, Paris, France
| |
Collapse
|
6
|
Regenthal P, Hansen JS, André I, Lindkvist-Petersson K. Thermal stability and structural changes in bacterial toxins responsible for food poisoning. PLoS One 2017; 12:e0172445. [PMID: 28207867 PMCID: PMC5313198 DOI: 10.1371/journal.pone.0172445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 02/03/2017] [Indexed: 11/17/2022] Open
Abstract
The staphylococcal enterotoxins (SEs) are secreted by the bacteria Staphylococcus aureus and are the most common causative agent in staphylococcal food poisoning. The staphylococcal enterotoxin A (SEA) has been associated with large staphylococcal food poisoning outbreaks, but newer identified SEs, like staphylococcal enterotoxin H (SEH) has recently been shown to be present at similar levels as SEA in food poisoning outbreaks. Thus, we set out to investigate the thermo-stability of the three-dimensional structures of SEA, SEH and staphylococcal enterotoxin E (SEE), since heat inactivation is a common method to inactivate toxins during food processing. Interestingly, the investigated toxins behaved distinctly different upon heating. SEA and SEE were more stable at slightly acidic pH values, while SEH adopted an extremely stable structure at neutral pH, with almost no effects on secondary structural elements upon heating to 95°C, and with reversible formation of tertiary structure upon subsequent cooling to room temperature. Taken together, the data suggests that the family of staphylococcal enterotoxins have different ability to withstand heat, and thus the exact profile of heat inactivation for all SEs causing food poisoning needs to be considered to improve food safety.
Collapse
Affiliation(s)
- Paulina Regenthal
- Department of Experimental Medical Science, Lund University, BMC, Lund, Sweden
| | - Jesper S Hansen
- Department of Experimental Medical Science, Lund University, BMC, Lund, Sweden
| | - Ingemar André
- Department of Biochemistry and Structural Biology, Lund University, Lund, Sweden
| | | |
Collapse
|
7
|
Rödström KEJ, Regenthal P, Lindkvist-Petersson K. Structure of Staphylococcal Enterotoxin E in Complex with TCR Defines the Role of TCR Loop Positioning in Superantigen Recognition. PLoS One 2015; 10:e0131988. [PMID: 26147596 PMCID: PMC4492778 DOI: 10.1371/journal.pone.0131988] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 06/09/2015] [Indexed: 11/18/2022] Open
Abstract
T cells are crucial players in cell-mediated immunity. The specificity of their receptor, the T cell receptor (TCR), is central for the immune system to distinguish foreign from host antigens. Superantigens are bacterial toxins capable of inducing a toxic immune response by cross-linking the TCR and the major histocompatibility complex (MHC) class II and circumventing the antigen specificity. Here, we present the structure of staphylococcal enterotoxin E (SEE) in complex with a human T cell receptor, as well as the unligated T cell receptor structure. There are clear structural changes in the TCR loops upon superantigen binding. In particular, the HV4 loop moves to circumvent steric clashes upon complex formation. In addition, a predicted ternary model of SEE in complex with both TCR and MHC class II displays intermolecular contacts between the TCR α-chain and the MHC, suggesting that the TCR α-chain is of importance for complex formation.
Collapse
Affiliation(s)
- Karin E. J. Rödström
- Department of Experimental Medical Science, Lund University, BMC C13, 22 184, Lund, Sweden
| | - Paulina Regenthal
- Department of Experimental Medical Science, Lund University, BMC C13, 22 184, Lund, Sweden
| | | |
Collapse
|
8
|
Hedlund G, Eriksson H, Sundstedt A, Forsberg G, Jakobsen BK, Pumphrey N, Rödström K, Lindkvist-Petersson K, Björk P. The tumor targeted superantigen ABR-217620 selectively engages TRBV7-9 and exploits TCR-pMHC affinity mimicry in mediating T cell cytotoxicity. PLoS One 2013; 8:e79082. [PMID: 24194959 PMCID: PMC3806850 DOI: 10.1371/journal.pone.0079082] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 09/26/2013] [Indexed: 01/20/2023] Open
Abstract
The T lymphocytes are the most important effector cells in immunotherapy of cancer. The conceptual objective for developing the tumor targeted superantigen (TTS) ABR-217620 (naptumomab estafenatox, 5T4Fab-SEA/E-120), now in phase 3 studies for advanced renal cell cancer, was to selectively coat tumor cells with cytotoxic T lymphocytes (CTL) target structures functionally similar to natural CTL pMHC target molecules. Here we present data showing that the molecular basis for the anti-tumor activity by ABR-217620 resides in the distinct interaction between the T cell receptor β variable (TRBV) 7-9 and the engineered superantigen (Sag) SEA/E-120 in the fusion protein bound to the 5T4 antigen on tumor cells. Multimeric but not monomeric ABR-217620 selectively stains TRBV7-9 expressing T lymphocytes from human peripheral blood similar to antigen specific staining of T cells with pMHC tetramers. SEA/E-120 selectively activates TRBV7-9 expressing T lymphocytes resulting in expansion of the subset. ABR-217620 selectively triggers TRBV7-9 expressing cytotoxic T lymphocytes to kill 5T4 positive tumor cells. Furthermore, ABR-217620 activates TRBV7-9 expressing T cell line cells in the presence of cell- and bead-bound 5T4 tumor antigen. Surface plasmon resonance analysis revealed that ABR-217620 binds to 5T4 with high affinity, to TRBV7-9 with low affinity and to MHC class II with very low affinity. The T lymphocyte engagement by ABR-217620 is constituted by displaying high affinity binding to the tumor cells (KD approximately 1 nM) and with the mimicry of natural productive immune TCR-pMHC contact using affinities of around 1 µM. This difference in kinetics between the two components of the ABR-217620 fusion protein will bias the binding towards the 5T4 target antigen, efficiently activating T-cells via SEA/E-120 only when presented by the tumor cells.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Karin Rödström
- Experimental Medical Science, Lund University, Lund, Sweden
| | | | | |
Collapse
|
9
|
Forsberg G, Skartved NJ, Wallén-Öhman M, Nyhlén HC, Behm K, Hedlund G, Nederman T. Naptumomab Estafenatox, an Engineered Antibody-superantigen Fusion Protein With Low Toxicity and Reduced Antigenicity. J Immunother 2010; 33:492-9. [DOI: 10.1097/cji.0b013e3181d75820] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
10
|
René-Trouillefou M, Benzaria A, Marchal S, Lange R, Caporiccio B, Dumay E. Staphylococcal enterotoxin A: Partial unfolding caused by high pressure or denaturing agents enhances superantigenicity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2010; 1804:1322-33. [DOI: 10.1016/j.bbapap.2010.01.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Revised: 01/17/2010] [Accepted: 01/21/2010] [Indexed: 10/19/2022]
|
11
|
Li H, Zhao Y, Guo Y, VanVranken SJ, Li Z, Eisele L, Mourad W. Mutagenesis, biochemical, and biophysical characterization of Mycoplasma arthritidis-derived mitogen. Mol Immunol 2006; 44:763-73. [PMID: 16753217 PMCID: PMC3923304 DOI: 10.1016/j.molimm.2006.04.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Accepted: 04/11/2006] [Indexed: 02/02/2023]
Abstract
Mycoplasma arthritidis-derived mitogen (MAM) is a superantigen (SAg) that can activate large fractions of T cells bearing particular TCR Vbeta elements. Here we report the mutagenesis, biochemical and biophysical studies on the dimerization of MAM in solution. Our studies showed that although MAM mainly exists as a monomer in solution, a small percentage of MAM molecules form homodimer at high protein concentration, regardless of the presence of Zn2+. A distinct peak corresponding to a MAM homodimer was detected in the presence of EDTA, using both chemical cross-linking and analytical ultracentrifugation methods. Further mutagenesis studies revealed that single mutation of residues at the interface of the crystallographic dimer of MAM does not significantly affect the dimerization of MAM in solution. Circular dichroism (CD) analysis indicated that addition of Zn2+ does not induce conformational changes of MAM from its apo-state. Thermal denaturation experiments indicated that addition of Zn2+ to MAM solution resulted in a decrease of melting point (Tm), whereas addition of EDTA did not affect the Tm of MAM. These results imply that there is no defined Zn2+-binding site on MAM.
Collapse
Affiliation(s)
- Hongmin Li
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
- Department of Biomedical Sciences, School of Public Health, University at Albany, State University of New York, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
- Corresponding author. Tel.: +1 518 486 9154; fax: +1 518 474 7992. (H. Li)
| | - Yiwei Zhao
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
| | - Yi Guo
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
| | - Sandra J. VanVranken
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
| | - Zhong Li
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
| | - Leslie Eisele
- Wadsworth Center, New York State Department of Health, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, United States
| | - Walid Mourad
- Université de Montreal, CHUM, Campus St-Luc, PEA, 264, Boul. René Lévesque Est, Bureau 313, Montréal, Qué. H2X 1P1, Canada
| |
Collapse
|
12
|
Sørensen P, Kussmann M, Rosén A, Bennett KL, Thrige DDG, Uvebrant K, Walse B, Roepstorff P, Björk P. Identification of Protein-Protein Interfaces Implicated in CD80-CD28 Costimulatory Signaling. THE JOURNAL OF IMMUNOLOGY 2004; 172:6803-9. [PMID: 15153498 DOI: 10.4049/jimmunol.172.11.6803] [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 B7 ligands CD80 and CD86 on APCs deliver either costimulatory or inhibitory signals to the T cell when interacting with their counter-receptors CD28 and CD152 (CTLA-4) on the T cell surface. Although crucial for lymphocyte regulation, the structural basis of these interactions is still not completely understood. Using multivalent presentation and conditions mimicking clustering, believed to be essential for signaling through these receptors, and by applying a combined differential mass spectrometry and structural mapping approach to these conditions, we were able to identify a putative contact area involving hydrophilic regions on both CD28 and CD80 as well as a putative CD28 oligomerization interface induced by B7 ligation. Analysis of the CD80-CD28 interaction site reveals a well-defined interface structurally distinct from that of CD80 and CD152 and thus provides valuable information for therapeutic intervention targeted at this pathway, suggesting a general approach for other receptors.
Collapse
|
13
|
Abstract
Superantigens (SAGs) cause a massive T-cell proliferation by simultaneously binding to major histocompatibility complex (MHC) class II on antigen-presenting cells and T-cell receptors (TCRs) on T cells. These T-cell mitogens can cause disease in host, such as food poisoning or toxic shock. The best characterized groups of SAGs are the bacterial SAGs secreted by Staphylococcus aureus and Streptococcus pyogenes. Despite a common overall three-dimensional fold of these SAGs, they have been shown to bind to MHC class II in different ways. Recently, it has also been shown that SAGs have individual preferences in their binding to the TCRs. They can interact with various regions of the variable beta-chain of TCRs and at least one SAG seems to bind to the alpha-chain of TCRs. In this review, different subclasses of SAGs are classified based upon their binding mode to MHC class II, and models of trimolecular complexes of MHC-SAG-TCR molecules are described in order to reveal and understand the complexity of SAG-mediated T-cell activation.
Collapse
|
14
|
Erlandsson E, Andersson K, Cavallin A, Nilsson A, Larsson-Lorek U, Niss U, Sjöberg A, Wallén-Ohman M, Antonsson P, Walse B, Forsberg G. Identification of the antigenic epitopes in staphylococcal enterotoxins A and E and design of a superantigen for human cancer therapy. J Mol Biol 2003; 333:893-905. [PMID: 14583188 DOI: 10.1016/j.jmb.2003.09.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Monoclonal antibodies have a potential for cancer therapy that may be further improved by linking them to effector molecules such as superantigens. Tumor targeting of a superantigen leads to a powerful T cell attack against the tumour tissue. Encouraging results have been observed preclinically and in patients using the superantigen staphylococcal enterotoxin A, SEA. To further improve the concept, we have reduced the reactivity to antibodies against superantigens, which is found in all individuals. Using epitope mapping, antibody binding sites in SEA and SEE were found around their MHC class II binding sites. These epitopes were removed genetically and a large number of synthetic superantigens were produced in an iterative engineering procedure. Properties such as decreased binding to anti-SEA as well as higher selectivity to induce killing of tumour cells compared to MHC class II expressing cells, were sequentially improved. The lysine residues 79, 81, 83 and 84 are all part of major antigenic epitopes, Gln204, Lys74, Asp75 and Asn78 are important for optimal killing of tumour cells while Asp45 affects binding to MHC class II. The production properties were optimised by further engineering and a novel synthetic superantigen, SEA/E-120, was designed. It is recognised by approximately 15% of human anti-SEA antibodies and have more potent tumour cell killing properties than SEA. SEA/E-120 is likely to have a low toxicity due to its reduced capacity to mediate killing of MHC class II expressing cells. It is produced as a Fab fusion protein at approximately 35 mg/l in Escherichia coli.
Collapse
Affiliation(s)
- Eva Erlandsson
- Active Biotech Research AB, Box 724, 220 07 Lund, Sweden
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Langlois MA, El Fakhry Y, Mourad W. Zinc-binding sites in the N terminus of Mycoplasma arthritidis-derived mitogen permit the dimer formation required for high affinity binding to HLA-DR and for T cell activation. J Biol Chem 2003; 278:22309-15. [PMID: 12676930 DOI: 10.1074/jbc.m300823200] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Zinc-dependent superantigens can be divided into two subfamilies based on how they use zinc ions for interactions with major histocompatibility complex (MHC) class II molecules. Members of the first subfamily use zinc ions for interactions with histidine 81 on the beta-chain of MHC class II molecules, whereas members of the second subfamily use zinc ions for dimer formation. The zinc-binding motif is located in the C terminus of the molecule in both subfamilies. While our recent studies with Mycoplasma arthritidis-derived mitogen (MAM) have provided the first direct evidence demonstrating the binding to MHC class II molecules in a zinc-dependent manner, it still not known how zinc coordinates the interaction. Data presented here show that the zinc ion is mainly required to induce MAM/MAM dimer formation. Residues in the N terminus of MAM are involved in dimer formation and MHC class II binding, while histidine 14 and aspartic acid 31 of the MAM sequence are the major residues mediating MAM/MAM dimerization. Zinc-induced dimer formation is necessary for MAM binding, MHC class II-induced cell-cell adhesion, and efficient T cell activation. Together these results depict the unique mode of interaction of MAM in comparison with other superantigens.
Collapse
Affiliation(s)
- Marc-André Langlois
- Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier de l'université Laval, Faculté de Médecine, Université Laval, Quebec G1V 4G2, Canada
| | | | | |
Collapse
|
16
|
Swietnicki W, Barnie AM, Dyas BK, Ulrich RG. Zinc binding and dimerization of Streptococcus pyogenes pyrogenic exotoxin C are not essential for T-cell stimulation. J Biol Chem 2003; 278:9885-95. [PMID: 12473669 DOI: 10.1074/jbc.m206957200] [Citation(s) in RCA: 16] [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
Streptococcal pyrogenic enterotoxin C (Spe-C) is a superantigen virulence factor produced by Streptococcus pyogenes that activates T-cells polyclonally. The biologically active form of Spe-C is thought to be a homodimer containing an essential zinc coordination site on each subunit, consisting of the residues His(167), His(201), and Asp(203). Crystallographic data suggested that receptor specificity is dependent on contacts between the zinc coordination site of Spe-C and the beta-chain of the major histocompatibility complex type II (MHCII) molecule. Our results indicate that only a minor fraction of dimer is present at T-cell stimulatory concentrations of Spe-C following mutation of the unpaired side chain of cysteine at residue 27 to serine. Mutations of amino acid residues His(167), His(201), or Asp(203) had only minor effects on protein stability but resulted in greatly diminished MHCII binding, as measured by surface plasmon resonance with isolated receptor/ligand pairs and flow cytometry with MHCII-expressing cells. However, with the exception of the mutants D203A and D203N, mutation of the zinc-binding site of Spe-C did not significantly impact T-cell activation. The mutation Y76A, located in a polar pocket conserved among most superantigens, resulted in significant loss of T-cell stimulation, although no effect was observed on the overall binding to human MHCII molecules, perhaps because of the masking of this lower affinity interaction by the dominant zinc-dependent binding. To a lesser extent, mutations of side chains found in a second conserved MHCII alpha-chain-binding site consisting of a hydrophobic surface loop decreased T-cell stimulation. Our results demonstrate that dimerization and zinc coordination are not essential for biological activity of Spe-C and suggest the contribution of an alternative MHCII binding mode to T-cell activation.
Collapse
MESH Headings
- Amino Acid Sequence
- Antigens/chemistry
- Aspartic Acid/chemistry
- Bacterial Toxins/chemistry
- Binding Sites
- Binding, Competitive
- Cations
- Chromatography, Gel
- Chromatography, Liquid
- Circular Dichroism
- Cloning, Molecular
- DNA, Complementary/metabolism
- Dimerization
- Dose-Response Relationship, Drug
- Histidine/chemistry
- Humans
- Hydrogen-Ion Concentration
- Kinetics
- Mass Spectrometry
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Protein Binding
- Protein Structure, Secondary
- Receptors, Antigen, T-Cell/metabolism
- Recombinant Proteins/chemistry
- Sequence Homology, Amino Acid
- Serine/chemistry
- Streptococcus pyogenes/metabolism
- Surface Plasmon Resonance
- T-Lymphocytes/metabolism
- Thermodynamics
- Ultraviolet Rays
- Zinc/chemistry
- Zinc/metabolism
Collapse
Affiliation(s)
- Wieslaw Swietnicki
- United States Army Medical Research Institute of Infectious Diseases, Frederick, Maryland 21702, USA.
| | | | | | | |
Collapse
|
17
|
Petersson K, Thunnissen M, Forsberg G, Walse B. Crystal structure of a SEA variant in complex with MHC class II reveals the ability of SEA to crosslink MHC molecules. Structure 2002; 10:1619-26. [PMID: 12467569 DOI: 10.1016/s0969-2126(02)00895-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Although the biological properties of staphylococcal enterotoxin A (SEA) have been well characterized, structural insights into the interaction between SEA and major histocompatibilty complex (MHC) class II have only been obtained by modeling. Here, the crystal structure of the D227A variant of SEA in complex with human MHC class II has been determined by X-ray crystallography. SEA(D227A) exclusively binds with its N-terminal domain to the alpha chain of HLA-DR1. The ability of one SEA molecule to crosslink two MHC molecules was modeled. It shows that this SEA molecule cannot interact with the T cell receptor (TCR) while a second SEA molecule interacts with MHC. Because of its relatively low toxicity, the D227A variant of SEA is used in tumor therapy.
Collapse
Affiliation(s)
- Karin Petersson
- Molecular Biophysics, Centre for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, S-221 00 Lund, Sweden
| | | | | | | |
Collapse
|
18
|
Ilbäck NG, Persson R, Gunnarsson K, Stålhandske T. A new screening model for safety evaluation of superantigen-antibody recombinant fusion proteins (mAb Fab-SEA/E) using telemetric monitoring in conscious rabbits. J Pharmacol Toxicol Methods 2002; 48:31-9. [PMID: 12750039 DOI: 10.1016/s1056-8719(03)00006-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
INTRODUCTION Carcinoma recognising monoclonal antibodies (mAb) and mutated forms of the T-cell-activating bacterial staphylococcal enterotoxin A/E (SEA/E) have been combined in single hybrid constructs (mAb Fab-SEA/E). By introducing substitutions in an MHC class II binding site, these harmful toxins can be converted into tolerable immunotoxins. Rabbits and humans are sensitive to SE toxins, and cardiovascular effects in rabbits are similar to those seen in septic shock in man. A new screening model using telemetry in conscious rabbits was applied in the safety evaluation of different mAb Fab-SEA/E constructs administered intravenously. METHODS Telemetry transmitters were implanted in the peritoneal cavity of animals with a pressure catheter in the aorta and electrodes for ECG recording subcutaneously following administration of mAb Fab-SEA/E constructs intravenously. RESULTS The responses in body temperature, heart rate, and blood pressure varied depending on the treatment regimen and the mutations of the drug given. For example, 25 micro g/kg of C215 Fab-SEAmut9 were given as a first treatment cycle on days 1, 5, and 7 and as a second treatment cycle on days 13-15. The first dose induced high fever, whereas the second and third doses induced fever responses more rapidly and were of lower and shorter duration. The second treatment cycle, starting on day 13, did not induce any responses probably due to anti-SEA antibodies formed because of the treatment. Another construct, 5T4 Fab-SEA/E-11 at 50 micro g/kg, induced a similar response as C215 Fab-SEAmut9 on days 1, 5, and 7. In this case, the pharmacologic response was still present on days 13-15, though no clinical signs developed or no formation of anti-SEA antibodies occurred. When 50 micro g/kg of 5T4 Fab-SEA/E-11 was administered once daily for 4 days, body temperature after the first dose increased slowly during the first 24 h, whereas the second to fourth doses induced more rapid and higher responses. The fourth dose of another compound, K305 Fab-SEA/E-11 (50 micro g/kg), induced an even more pronounced response both in magnitude and in duration as well as in adverse clinical signs. DISCUSSION By using continuous telemetric registration in the rabbit as a tool in superantigen-antibody (mAb Fab-SEA/E) drug selection, it has been possible to evaluate the dynamics of drug-induced immune effects (fever) and concomitant engagement of the cardiovascular system, conditions that are essential before clinical trials can be initiated.
Collapse
|
19
|
Affiliation(s)
- C Bachert
- Department of Oto-Rhino-Laryngology, Ghent University Hospital, Ghent, Belgium
| | | | | |
Collapse
|
20
|
Baker M, Gutman DM, Papageorgiou AC, Collins CM, Acharya KR. Structural features of a zinc binding site in the superantigen strepococcal pyrogenic exotoxin A (SpeA1): implications for MHC class II recognition. Protein Sci 2001; 10:1268-73. [PMID: 11369867 PMCID: PMC2374012 DOI: 10.1110/ps.330101] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Streptococcal pyrogenic exotoxin A (SpeA) is produced by Streptococcus pyogenes, and has been associated with severe infections such as scarlet fever and Streptococcal Toxic Shock Syndrome (STSS). In this study, the crystal structure of SpeA1 (the product of speA allele 1) in the presence of 2.5 mM zinc was determined at 2.8 A resolution. The protein crystallizes in the orthorhombic space group P2(1)2(1)2, with four molecules in the crystallographic asymmetric unit. The final structure has a crystallographic R-factor of 21.4% for 7,031 protein atoms, 143 water molecules, and 4 zinc atoms (one zinc atom per molecule). Four protein ligands-Glu 33, Asp 77, His 106, and His 110-form a zinc binding site that is similar to the one observed in a related superantigen, staphylococcoal enterotoxin C2. Mutant toxin forms substituting Ala for each of the zinc binding residues were generated. The affinity of these mutants for zinc ion confirms the composition of this metal binding site. The implications of zinc binding to SpeA1 for MHC class II recognition are explored using a molecular modeling approach. The results indicate that, despite their common overall architecture, superantigens appear to have multiple ways of complex formation with MHC class II molecules.
Collapse
Affiliation(s)
- M Baker
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | | | | | | | | |
Collapse
|
21
|
Hâkansson M, Petersson K, Nilsson H, Forsberg G, Björk P, Antonsson P, Svensson LA. The crystal structure of staphylococcal enterotoxin H: implications for binding properties to MHC class II and TcR molecules. J Mol Biol 2000; 302:527-37. [PMID: 10986116 DOI: 10.1006/jmbi.2000.4093] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The X-ray structure of the superantigen staphylococcal enterotoxin H (SEH) has been determined at 1.69 A resolution. In this paper we present two structures of zinc-free SEH (apoSEH) and one zinc-loaded form of SEH (ZnSEH). SEH exhibits the conventional superantigen (SAg) fold with two characteristic domains. In ZnSEH one zinc ion per SEH molecule is bound to the C-terminal beta-sheet in the region implicated for major histocompatibility complex class II (MHC class II) binding in SEA, SED and SEE. Surprisingly, the zinc ion has only two ligating amino acid residues His206 and Asp208. The other ligands to the zinc ion are two water molecules. An extensive packing interaction between two symmetry-related molecules in the crystal, 834 A(2)/molecule, forms a cavity that buries the zinc ions of the molecules. This dimer-like interaction is found in two crystal forms. Nevertheless, zinc-dependent dimerisation is not observed in solution, as seen in the case of SED. A unique feature of SEH as compared to other staphylococcal enterotoxins is a large negatively charged surface close to the Zn(2+) site. The interaction of SEH with MHC class II is the strongest known among the staphylococcal enterotoxins. However, SEH seems to lack a SEB-like MHC class II binding site, since the side-chain properties of structurally equivalent amino acid residues in SEH and those in SEB-binding MHC class II differ dramatically. There is also a structural flexibility between the domains of SEH. The domains of two apoSEH structures are related by a 5 degrees rotation leading to at most 3 A difference in C(alpha) positions. Since the T-cell receptor probably interacts with both domains, SEH by this rotation may modulate its binding to different TcR Vbeta-chains.
Collapse
Affiliation(s)
- M Hâkansson
- Molecular Biophysics, Centre for Chemistry and Chemical Engineering, Lund University, Lund, S-221 00, Sweden
| | | | | | | | | | | | | |
Collapse
|