TY - JOUR
T1 - Isolation and functional analysis of phage-displayed antibody fragments targeting the staphylococcal superantigen-like proteins
AU - Alanko, Ida
AU - Sandberg, Rebecca
AU - Brockmann, Eeva Christine
AU - de Haas, Carla J.C.
AU - van Strijp, Jos A.G.
AU - Lamminmäki, Urpo
AU - Salo-Ahen, Outi M.H.
N1 - Funding Information:
Tor, Joe, and Pentti Borg's Memorial Foundation and the Orion Research Foundation Sr are acknowledged for financial support of this study. The Sigrid Jusélius Foundation, Biocenter Finland Bioinformatics, CSC IT Center for Science, and Prof. Mark Johnson and Dr. Jukka Lehtonen are gratefully acknowledged for the excellent computational infrastructure at the Åbo Akademi University. This work contributes also to the activities within the strategic research profiling area “Solutions for Health” at Åbo Akademi University (Academy of Finland, # 336355).
Funding Information:
Tor, Joe, and Pentti Borg's Memorial Foundation and the Orion Research Foundation Sr are acknowledged for financial support of this study. The Sigrid Jusélius Foundation, Biocenter Finland Bioinformatics, CSC IT Center for Science, and Prof. Mark Johnson and Dr. Jukka Lehtonen are gratefully acknowledged for the excellent computational infrastructure at the Åbo Akademi University. This work contributes also to the activities within the strategic research profiling area “Solutions for Health” at Åbo Akademi University (Academy of Finland, # 336355).
Publisher Copyright:
© 2023 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.
PY - 2023/8
Y1 - 2023/8
N2 - Staphylococcus aureus produces numerous virulence factors that manipulate the immune system, helping the bacteria avoid phagocytosis. In this study, we are investigating three immune evasion molecules called the staphylococcal superantigen-like proteins 1, 5, and 10 (SSL1, SSL5, and SSL10). All three SSLs inhibit vital host immune processes and contribute to S. aureus immune evasion. This study aimed to identify single-chain variable fragment (scFvs) antibodies from synthetic antibody phage libraries, which can recognize either of the three SSLs and could block the interaction between the SSLs and their respective human targets. The antibodies were isolated after three rounds of panning against SSL1, SSL5, and SSL10, and their ability to bind to the SSLs was studied using a time-resolved fluorescence-based immunoassay. We successfully obtained altogether 44 unique clones displaying binding activity to either SSL1, SSL5, or SSL10. The capability of the SSL-recognizing scFvs to inhibit the SSLs' function was tested in an MMP9 enzymatic activity assay, a P-selectin glycoprotein ligand 1 competitive binding assay, and an IgG1-mediated phagocytosis assay. We could show that one scFv was able to inhibit SSL1 and maintain MMP9 activity in a concentration-dependent manner. Finally, the structure of this inhibiting scFv was modeled and used to create putative scFv-SSL1-complex models by protein–protein docking. The complex models were subjected to a 100-ns molecular dynamics simulation to assess the possible binding mode of the antibody.
AB - Staphylococcus aureus produces numerous virulence factors that manipulate the immune system, helping the bacteria avoid phagocytosis. In this study, we are investigating three immune evasion molecules called the staphylococcal superantigen-like proteins 1, 5, and 10 (SSL1, SSL5, and SSL10). All three SSLs inhibit vital host immune processes and contribute to S. aureus immune evasion. This study aimed to identify single-chain variable fragment (scFvs) antibodies from synthetic antibody phage libraries, which can recognize either of the three SSLs and could block the interaction between the SSLs and their respective human targets. The antibodies were isolated after three rounds of panning against SSL1, SSL5, and SSL10, and their ability to bind to the SSLs was studied using a time-resolved fluorescence-based immunoassay. We successfully obtained altogether 44 unique clones displaying binding activity to either SSL1, SSL5, or SSL10. The capability of the SSL-recognizing scFvs to inhibit the SSLs' function was tested in an MMP9 enzymatic activity assay, a P-selectin glycoprotein ligand 1 competitive binding assay, and an IgG1-mediated phagocytosis assay. We could show that one scFv was able to inhibit SSL1 and maintain MMP9 activity in a concentration-dependent manner. Finally, the structure of this inhibiting scFv was modeled and used to create putative scFv-SSL1-complex models by protein–protein docking. The complex models were subjected to a 100-ns molecular dynamics simulation to assess the possible binding mode of the antibody.
KW - antivirulence strategy
KW - phage display
KW - scFv
KW - staphylococcal superantigen-like protein
KW - Staphylococcus aureus
UR - http://www.scopus.com/inward/record.url?scp=85165469688&partnerID=8YFLogxK
U2 - 10.1002/mbo3.1371
DO - 10.1002/mbo3.1371
M3 - Article
C2 - 37642487
AN - SCOPUS:85165469688
VL - 12
SP - 1
EP - 19
JO - MicrobiologyOpen
JF - MicrobiologyOpen
IS - 4
M1 - e1371
ER -