همایش ملی بیوانفورماتیک ایران

صفحه اصلی / 4th international edition and 13th Iranian Conference on Bioinformatics

Site-Directed Mutagenesis to Optimize Anti- TIM-3 Antibody Affinity through In-Silico Modeling

نویسندگان :

Zahra Sohrabi nasr¹ Mehri Khatami² Mohammad mahdi Heidari³

1- دانشگاه یزد 2- دانشگاه یزد 3- دانشگاه یزد

کلمات کلیدی :

Tim-3،Site directed mutagenesis،Antibody affinity،Monoclonal antibody

چکیده :

T-cell immunoglobulin and mucin domain 3 (Tim-3) has been identified as a marker for differentiated interferon-gamma (IFN-γ)-producing CD4+ T helper type 1 (Th1) cells and CD8+ T cytotoxic type 1 (Tc1) cells. Tim-3 serves as an inhibitory co-receptor that plays a crucial role in maintaining the balance between normal immune responses and dysfunctional ones. It has a diverse function related to T cell exhaustion and tolerance, particularly noted in various chronic viral infections in humans. Tim-3 acts as a negative regulator of both Th1 and Tc1 cell functions, promoting cell death when it interacts with its ligand, galectin-9 (Gal-9). This interaction triggers apoptosis, and blocking it in vivo has been shown to exacerbate autoimmunity and disrupt tolerance in experimental models, reinforcing Tim-3's role as a negative regulatory molecule. Consequently, Tim-3 has emerged as a potential therapeutic target and is currently being explored in both preclinical and clinical settings. Site-directed mutagenesis is an effective technique for improving the affinity between molecules. Given the significance of monoclonal antibodies in modern cancer and infectious disease therapies, greater attention should be directed towards site-directed mutagenesis methods. The aim of this research is to enhance the affinity of the anti-Tim-3 monoclonal antibody for Tim-3. To begin, the three-dimensional structure of Tim-3 in complex with the anti-Tim-3 antibody was retrieved from the Protein Data Bank (PDB) using the code 7KQL. The SabDab server was utilized to determine the sequencing of the antibody’s complementarity-determining regions (CDRs). Click or tap here to enter text. 4th International Iranian Conference on Bioinformatic Zanjan February 4-6. 2025 Paper Num: ICB13.2025……. 4th International Iranian Conference on Bioinformatic Zanjan February 4-6. 2025 Using the PyMOL tutorial server, we identified critical areas in the heavy chain CDRs of the antibody and Tim-3. Following this, PyMOL software was employed to examine the interaction between these two structures and to identify a mutation that could enhance the binding affinity of the antibody to Tim-3. The analysis conducted with PyMOL indicated that mutating the amino acid tyrosine (Y) at position 103 in the heavy chain of the anti-Tim-3 antibody to arginine (R) resulted in a reduction of the bond length between the antibody and Tim-3 from 2.6 angstroms to 2.2 angstroms. This suggests an improvement in the interaction between these two structures and enhances the affinity between the antibody and its antigen. The results of these findings are illustrated in Figures 1 and 2.