Identification of T cell epitope-based peptide vaccine from WT1 in Glioblastoma cancer
Identification of T cell epitope-based peptide vaccine from WT1 in Glioblastoma cancer
reza salahlou,1Safar Farajnia,2,*Effat Alizadeh,3Siavoush Dastmalchi,4
1. Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. 2. Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran 3. Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran. 4. Department of Medicinal Chemistry, School of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran.
Introduction: Introduction:
Glioblastoma (GBM) is the most aggressive primary malignant brain tumor in adults. Its complex genetic and molecular changes lead to rapid cell proliferation and invasion of surrounding tissues. Despite advancements in treatment, including surgery, radiation, and chemotherapy, the prognosis remains poor due to the tumor's infiltrative nature and the challenges posed by the blood-brain barrier. Immunotherapy, particularly peptide vaccines, has emerged as a promising approach to tackle GBM by harnessing the body’s immune system to target and destroy cancer cells. Peptide vaccines stimulate an immune response against specific tumor-associated antigens (TAAs) or tumor-specific antigens (TSAs) in GBM cells. These vaccines consist of short sequences of amino acids that mimic parts of these antigens, prompting the immune system to recognize and attack the tumor cells. Studies indicate a high association between histological tumor grades and WT1 levels, often overexpressed in GBM. WT1 expression has been shown via immunohistochemical analysis to be present in all astrocytomas, with higher expression in high-grade tumors. The oncogenic characteristics of WT1 position it as an up-and-coming candidate for immunotherapeutic interventions.
Methods: Methods:
The amino acid sequence of the WT1 protein (ID: P19544) was retrieved from the UniProt database. We aimed to find CTL epitopes in WT-1 that are restricted by the HLA-B*0702 molecules to improve the applicability of WT-1-based immunotherapy. Peptides from WT1 that are restricted by HLA-B*0702 were discovered through the use of three advanced servers: SYFPEITHI, IEBD, and NetMHCpan-4.1. Epitopes were selected based on their antigenic and immunogenic properties using the VaxiJen v2.0 and IEDB Class I Immunogenicity tools, respectively. The ClusPro server was used for Molecular docking of the chosen CTL epitope with a particular Human Leukocyte Antigen (HLA) allele to evaluate their binding affinity. The LIGPLOT program was utilized to map the interaction between the residues of the peptide and HLA-B*0702 in the docked complex. The C-ImmSim tool was employed for in-silico immune simulation to analyze and understand immunogenicity and immune response profiles.
Results: Result:
We restricted our future screening to epitopes that presented recurrent patterns in three tools. Subsequently, these epitopes were evaluated based on their binding affinity, antigenicity, and immunogenicity, as demonstrated in Table 1. Although differences were observed according to the properties, only one CTL p163 peptide (TPSHHAAQF) exhibited positive antigenicity and immunogenicity. The ClusPro server was utilized to perform molecular docking to assess the binding affinity between the CTL peptide and its respective HLA allele. The complex consisting of the HLA-B*0702 and the CTL peptide with the lowest binding energy score of -629.1 kJ/mol was selected. The diagram illustrating the hydrogen bonds and hydrophobic interactions between the peptide and HLA-B*0702 was produced using the LigPlot v1.4.5 program (figure1). As part of the peptide-HLA complex, Gln155, Arg156, Asp114, Glu163, Arg62, Asn63, Tyr171, Tyr59, and Thr73 amino acid residues from HLA-B*0702 were implicated in the formation of hydrogen bonds. The findings from the C-ImmSim studies demonstrated that the CTL peptide elicited robust immune responses, characterized by a significant presence of cytotoxic T cells. The production of the cytokines & interleukins was identified along with increased DC and NK populations.
Conclusion: Conclusions: The results of this research show that the identification of a new CTL epitope presented by HLA-B*0702 increases the potential of WT1-based immunotherapy for cancer treatment.