Human scFvs That Counteract Bioactivities of Staphylococcus aureus TSST-1

Thunchanok Rukkawattanakul; Nitat Sookrung; Watee Seesuay; Nattawat Onlamoon; Pornphan Diraphat; Wanpen Chaicumpa; Nitaya Indrawattana

doi:10.3390/toxins9020050

Human scFvs That Counteract Bioactivities of Staphylococcus aureus TSST-1

Toxins (Basel). 2017 Feb 17;9(2):50. doi: 10.3390/toxins9020050.

Authors

Thunchanok Rukkawattanakul^{1

2}, Nitat Sookrung^{3

4}, Watee Seesuay⁵, Nattawat Onlamoon⁶, Pornphan Diraphat⁷, Wanpen Chaicumpa⁸, Nitaya Indrawattana⁹

Affiliations

¹ Graduate Program in Immunology, Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. ruk.thunchanok@gmail.com.
² 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.
³ 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.
⁴ Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. nitat.soo@mahidol.ac.th.
⁵ 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.
⁶ Department of Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand. nattawat.onl@mahidol.ac.th.
⁷ Department of Microbiology, Faculty of Public Health, Mahidol University, Bangkok 10400, Thailand. pornphan.dir@mahidol.ac.th.
⁸ 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.
⁹ Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand. nitaya.ind@mahidol.ac.th.

Abstract

Some Staphylococcus aureus isolates 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. Three E. coli clones 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.

Keywords: Staphylococcus aureus; Toxic shock syndrome (TSS); direct acting anti-TSST-1; human scFv; superantigen.

MeSH terms

Antibodies, Monoclonal, Humanized / genetics
Antibodies, Monoclonal, Humanized / metabolism
Antibodies, Monoclonal, Humanized / pharmacology*
Antibodies, Neutralizing / genetics
Antibodies, Neutralizing / metabolism
Antibodies, Neutralizing / pharmacology*
Bacterial Toxins / antagonists & inhibitors*
Bacterial Toxins / genetics
Bacterial Toxins / immunology
Bacterial Toxins / metabolism
Cell Surface Display Techniques
Cells, Cultured
Cytokines / metabolism
Enterotoxins / antagonists & inhibitors*
Enterotoxins / genetics
Enterotoxins / immunology
Enterotoxins / metabolism
Escherichia coli / genetics
Escherichia coli / metabolism
Histocompatibility Antigens Class II / metabolism
Host-Pathogen Interactions
Humans
Inflammation Mediators / metabolism
Lymphocyte Activation / drug effects
Mutation
Protein Binding
Receptors, Antigen, T-Cell, alpha-beta / metabolism
Shock, Septic / immunology
Shock, Septic / metabolism
Shock, Septic / microbiology
Shock, Septic / prevention & control*
Single-Chain Antibodies / genetics
Single-Chain Antibodies / metabolism
Single-Chain Antibodies / pharmacology*
Staphylococcal Infections / immunology
Staphylococcal Infections / metabolism
Staphylococcal Infections / microbiology
Staphylococcal Infections / prevention & control*
Staphylococcus aureus / drug effects*
Staphylococcus aureus / genetics
Staphylococcus aureus / immunology
Staphylococcus aureus / metabolism
Superantigens / genetics
Superantigens / immunology
Superantigens / metabolism
T-Lymphocytes / drug effects
T-Lymphocytes / immunology
T-Lymphocytes / metabolism
T-Lymphocytes / microbiology

Substances

Antibodies, Monoclonal, Humanized
Antibodies, Neutralizing
Bacterial Toxins
Cytokines
Enterotoxins
Histocompatibility Antigens Class II
Inflammation Mediators
Receptors, Antigen, T-Cell, alpha-beta
Single-Chain Antibodies
Superantigens
enterotoxin F, Staphylococcal