In silico analysis of STX2a-PE15-P4A8 chimeric protein as a novel immunotoxin for cancer therapy
Maryam Keshtvarz1, Jafar Salimian2, Jafar Amani3
1Division of Microbiology, Department of Pathobiology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Abstract:
Today, the targeted therapies like the use of immunotoxins are increased which targeted specific antigens or receptors on the surface of tumor cells. Fibroblast growth factor-inducible 14 (Fn14) is a cytokine receptor which involves several intercellular signaling pathways and can be highly expressed in the surface of cancer cells. Since the cleavage of enzymatic domain of Pseudomonas exotoxin A (PE) occurs in one step by furin protease, we fused enzymatic subunit of Shiga-like toxin type 2a (Stx2a) with domain II and a portion of Ib of PE to increase the toxicity of Stx. Then, we genetically fused the Fv fragment of an anti-Fn14 monoclonal antibody (P4A8) to STX2a-PE15 and evaluated the STX2a-PE15-P4A8 chimeric protein as a new immunotoxin candidate. In silico analysis showed that the STX2a-PE15-P4A8 is a stable chimeric protein with high affinity to the Fn14 receptor. Despite, the STX2a-PE15-P4A8 can be bind to the B cell receptor, but it has been weakly presented by major histocompatibility complex molecules II (MHC-II). So, it may have a little immunogenicity. On the basis of our in-silico studies we predict that STX2a-PE15-P4A8 can be a good candidate for cancer immunotherapy.
Supplementary Information:
The online version contains supplementary material available at 10.1007/s40203-021-00079-w.
Insights
A novel chimeric protein, STX2a-PE15-P4A8, targeting Fibroblast growth factor-inducible 14 (Fn14) shows promise as a cancer immunotherapy. In silico analysis indicates high affinity and low immunogenicity, suggesting potential for targeted tumor cell destruction.
Area of Science:
- Oncology
- Immunology
- Biotechnology
Background:
- Targeted therapies, including immunotoxins, are increasingly used to target tumor cells.
- Fibroblast growth factor-inducible 14 (Fn14) is a cytokine receptor highly expressed on cancer cells.
- Pseudomonas exotoxin A (PE) and Shiga-like toxin type 2a (Stx2a) are potent toxins with distinct mechanisms.
Purpose of the Study:
- To develop a novel immunotoxin targeting the Fn14 receptor for cancer immunotherapy.
- To engineer a chimeric protein combining Stx2a and PE with an anti-Fn14 antibody fragment.
- To evaluate the in silico stability, binding affinity, and immunogenicity of the novel construct.
Main Methods:
- Genetic fusion of the Stx2a enzymatic subunit with PE domains and an anti-Fn14 Fv fragment (P4A8).
- In silico analysis to assess the stability and binding affinity of the chimeric protein (STX2a-PE15-P4A8) to Fn14.
- Evaluation of potential immunogenicity by assessing binding to B cell receptors and presentation by MHC-II molecules.
Main Results:
- The STX2a-PE15-P4A8 chimeric protein was successfully designed and predicted to be stable.
- In silico analysis demonstrated high binding affinity of STX2a-PE15-P4A8 to the Fn14 receptor.
- The construct showed weak presentation by MHC-II, suggesting low immunogenicity.
Conclusions:
- STX2a-PE15-P4A8 is a promising candidate for cancer immunotherapy due to its targeted binding to Fn14.
- The engineered immunotoxin has a favorable in silico profile regarding stability and potential immunogenicity.
- Further studies are warranted to validate the therapeutic potential of STX2a-PE15-P4A8 in preclinical models.
