title: Human scFvs That Counteract Bioactivities of Staphylococcus aureus TSST-1.
abstract: SomeStaphylococcus aureusisolates produced toxic shock syndrome toxin-1 (TSST-1) which is a pyrogenic toxin superantigen (PTSAg). The toxin activates a large fraction of peripheral blood T lymphocytes causing the cells to proliferate and release massive amounts of pro-inflammatory cytokines leading to a life-threatening multisystem disorder: toxic shock syndrome (TSS). PTSAg-mediated-T cell stimulation circumvents the conventional antigenic peptide presentation to T cell receptor (TCR) by the antigen-presenting cell (APC). Instead, intact PTSAg binds directly to MHC-II molecule outside peptide binding cleft and simultaneously cross-links TCR-Vβ region. Currently, there is neither specific TSS treatment nor drug that directly inactivates TSST-1. In this study, human single chain antibodies (HuscFvs) that bound to and neutralized bioactivities of the TSST-1 were generated using phage display technology. ThreeE. coliclones transfected with TSST-1-bound phages fished-out from the human scFv library using recombinant TSST-1 as bait expressed TSST-1-bound-HuscFvs that inhibited the TSST-1-mediated T cell activation and pro-inflammatory cytokine gene expressions and productions.Computerized simulation, verified by mutations of the residues of HuscFv complementarity determining regions (CDRs),predicted to involve in target binding indicated that the HuscFvs formed interface contact with the toxin residues important for immunopathogenesis. The HuscFvs have high potential for future therapeutic application.
authors.affiliation: Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. ruk.thunchanok@gmail.com.|Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. ruk.thunchanok@gmail.com.
authors.forename: Thunchanok
authors.initials: T
authors.lastname: Rukkawattanakul
authors.affiliation: Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. nitat.soo@mahidol.ac.th.|Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. nitat.soo@mahidol.ac.th.
authors.forename: Nitat
authors.initials: N
authors.lastname: Sookrung
authors.affiliation: Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. watee.see@gmail.com.
authors.forename: Watee
authors.initials: W
authors.lastname: Seesuay
authors.affiliation: Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. nattawat.onl@mahidol.ac.th.
authors.forename: Nattawat
authors.initials: N
authors.lastname: Onlamoon
authors.affiliation: Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok 10400, Thailand. pornphan.dir@mahidol.ac.th.
authors.forename: Pornphan
authors.initials: P
authors.lastname: Diraphat
authors.affiliation: Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. wanpen.cha@mahidol.ac.th.
authors.forename: Wanpen
authors.initials: W
authors.lastname: Chaicumpa
authors.affiliation: Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand. nitaya.ind@mahidol.ac.th.
authors.forename: Nitaya
authors.initials: N
authors.lastname: Indrawattana
mesh_terms: D061067:Antibodies, Monoclonal, Humanized / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D057134:Antibodies, Neutralizing / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D001427:Bacterial Toxins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D061505:Cell Surface Display Techniques; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004768:Enterotoxins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D054884:Host-Pathogen Interactions; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D009154:Mutation; D011485:Protein Binding; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000378:metabolism; D012772:Shock, Septic / Q000276:immunology / Q000378:metabolism / Q000382:microbiology / Q000517:prevention & control*; D057127:Single-Chain Antibodies / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D013203:Staphylococcal Infections / Q000276:immunology / Q000378:metabolism / Q000382:microbiology / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D018089:Superantigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism / Q000382:microbiology
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D057134:Antibodies, Neutralizing; D001427:Bacterial Toxins; D016207:Cytokines; D004768:Enterotoxins; D000949:Histocompatibility Antigens Class II; D018836:Inflammation Mediators; D016693:Receptors, Antigen, T-Cell, alpha-beta; D057127:Single-Chain Antibodies; D018089:Superantigens; C030107:enterotoxin F, Staphylococcal
keywords: Staphylococcus aureus; Toxic shock syndrome (TSS); direct acting anti-TSST-1; human scFv; superantigen