A Precisely Designed Immunotoxin Against VCAM1 Consisting of a Humanized Antibody Variable Domain Fused to Granzyme: An In Silico Approach
INTERNATIONAL JOURNAL OF PEPTIDE RESEARCH AND THERAPEUTICS
Authors: Ganji, Mahmoud; Khalili, Saeed; Mard-Soltani, Maysam; Khalesi, Bahman; Karkhah, Ahmad; Amani, Jafar
Abstract
Atherosclerosis is a complex disease related to cardiovascular disorders and is one of the most considerable causes of mortality worldwide. It has been shown that the immune system plays a pivotal role in generating atherosclerosis plaques. The atherosclerosis plaques form via activation of endothelial cells by recruiting adhesion molecules such as VCAM1. Therefore, VCAM1 could be considered as a suitable target to design immune-therapeutics. In this regard, we have lunched an in silico approach to design an immunotoxin against VCAM1. The structure of an anti-VCAM1 antibody was predicted using homology modeling software. The structure of the predicted chains were linked by (Gly(4)Ser)(3) linker. Then, using various modeling software the structure of the GrB was linked to the antibody structure via an adaptor sequence. The final structure was energy minimized, evaluated for accuracy and characterized for its biological properties. Our results indicated that the employed structure prediction method has successfully managed to model the immunotoxin structure. Moreover, our results indicated that the designed immunotoxin is capable of VCAM1 interaction with proper orientation involving its C-D loop. In conclusion it should be pointed out that, the employed in silico approach could pave the way for precise and accurate design of immune-therapeutic agents against cancer. Using this approach we have designed an immunotoxin capable of VCAM1 targeting in a proper orientation and following cancer cell destruction by the toxin domain of the molecule.
RETRACTED: A homing system targets therapeutic T cells to brain cancer (Retracted article. See vol. 567, pg. 132, 2019)
NATURE
Authors: Samaha, Heba; Pignata, Antonella; Fousek, Kristen; Ren, Jun; Lam, Fong W.; Stossi, Fabio; Dubrulle, Julien; Salsman, Vita S.; Krishnan, Shanmugarajan; Hong, Sung-Ha; Baker, Matthew L.; Shree, Ankita; Gad, Ahmed Z.; Shum, Thomas; Fukumura, Dai; Byrd, Tiara T.; Mukherjee, Malini; Marrelli, Sean P.; Orange, Jordan S.; Joseph, Sujith K.; Sorensen, Poul H.; Taylor, Michael D.; Hegde, Meenakshi; Mamonkin, Maksim; Jain, Rakesh K.; El-Naggar, Shahenda; Ahmed, Nabil
Abstract
Successful T cell immunotherapy for brain cancer requires that the T cells can access tumour tissues, but this has been difficult to achieve. Here we show that, in contrast to inflammatory brain diseases such as multiple sclerosis, where endothelial cells upregulate ICAM1 and VCAM1 to guide the extravasation of pro-inflammatory cells, cancer endothelium downregulates these molecules to evade immune recognition. By contrast, we found that cancer endothelium upregulates activated leukocyte cell adhesion molecule (ALCAM , which allowed us to overcome this immune-evasion mechanism by creating an ALCAM-restricted homing system (HS). We re-engineered the natural ligand of ALCAM, CD6, in a manner that triggers initial anchorage of T cells to ALCAM and conditionally mediates a secondary wave of adhesion by sensitizing T cells to low-level ICAM1 on the cancer endothelium, thereby creating the adhesion forces necessary to capture T cells from the bloodstream. Cytotoxic HS T cells robustly infiltrated brain cancers after intravenous injection and exhibited potent antitumour activity. We have therefore developed a molecule that targets the delivery of T cells to brain cancer.