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 - Atherosclerosis is a complex disease related to cardiovascular disorders and is one of the most considerable causes of mortality...     

Anticancer Activity of Brevinin-2R Peptide and its Two Analogues Against Myelogenous Leukemia Cell Line as Natural Treatments: An In Vitro Study

Human chronic myelogenous leukemia (CML) is a stem cell driven hematological malignancy which shows resistance to existing therapeutics. This property of CML accentuates the necessity to develop alternative anti-CML therapeutic agents. Herein, we have evaluated the anticancer activity of a novel anticancer peptide, Brevinin-2R and its two analogues, Brevinin-2R-C and Brevinin-2R-D regarding their inhibitory activity against K562 cells. Various cell-based analyses have been conducted to analyze the effects of these peptides and their mechanism of action. Hematotoxicity assay was performed to determine their hemolytic activities. MTT and neutral red uptake assays were conducted to examine anti-proliferative effects, propidium iodide (PI) staining to monitor the DNA content in different phases of cell cycle and Annexin V/PI staining to detect the apoptosis induction for the peptides. Our findings indicated that these peptides are capable of diminishing the cell growth and inducing apoptosis and cell cycle arrest. Brevinin-2R and its two analogues inhibited cell proliferation through strong cell cycle arrest in G2/M phase leading to apoptosis induction. The cytotoxicity of Brevinin-2R was higher than that of its two derivatives. These observations have provided new insights into the therapeutic activity of Brevinin-2R and its two analogues and suggest that these peptides have the potential to act as anticancer agents in treatment of K562. Further in vivo investigations on the therapeutic potential of Brevinin-2R and its two analogues are required to get a better grasp of their mechanism of action.

     

Structure Based Screening for Inhibitory Therapeutics of CTLA-4 Unveiled New Insights About Biology of ACTH

Although the biology of adrenocorticotropic hormone (ACTH) protein has already been scrutinized, some functional aspects of its biology are yet to be elucidated in the context of immunological disorders. In this regard, virtual screening of a compound library was performed against the structure of Cytotoxic T-Lymphocyte Associated Protein-4 (CTLA-4) (assessed both spatially and energetically) to discover novel biological functions for ACTH. The results of virtual screening and the MD simulation demonstrated that DB01284 has high binding energy along with proper interaction orientation against CTLA-4 (FG loop) by a clamp like structure. The employed methodology was checked using confirmatory control analyses. Intriguingly, DB01284 belongs to Tetracosactide (already prescribed protein drug for clinical conditions) which is the N-terminal region of ACTH. This is the first study to reveal that ACTH protein binds to the same amino acids of CTLA-4 (FG-loop) as B7 and anti-CTLA-4 antibody binds. In light of this finding, the molecular mechanism of ACTH function in patients suffering from Cushing’s Syndrom and the immunological bases for ACTH therapy of multiple sclerosis (MS) patients could be further delineated. Moreover, this finding suggests that ACTH could also act to block CTLA-4 in the context of anticancer immune check point blockade.

     

PD-1/PD-L1-dependent immune response in colorectal cancer

Colorectal cancer (CRC) is still considered as the third most frequent cancer in the world. Microsatellite instability (MSI), inflammation, and microRNAs have been demonstrated as the main contributing factors in CRC. Subtype 1 CRC is defined by NK cells infiltration, induction of Th1 lymphocyte and cytotoxic T cell responses as well as upregulation of immune checkpoint proteins including programmed cell death-1 (PD-1). Based on the diverse features of CRC, such as the stage and localization of the tumor, several treatment approaches are available. However, the efficiency of these treatments may be decreased due to the development of diverse resistance mechanisms. It has been proven that monoclonal antibodies (mAbs) can increase the effectiveness of CRC treatments. Nowadays, several mAbs including nivolumab and pembrolizumab have been approved for the treatment of CRC. Immune checkpoint receptors including PD-1 can be inhibited by these antibodies. Combination therapy gives an opportunity for advanced treatment for CRC patients. In this review, an update has been provided on the molecular mechanisms involved in MSI colorectal cancer immune microenvironment by focusing on PD-ligand 1 (PD-L1) and treatment of patients with advanced immunotherapy, which were examined in the different clinical trial phases. Considering induced expression of PD-L1 by conventional chemotherapeutics, we have summarized the role of PD-L1 in CRC, the chemotherapy effects on the PD-1/PD-L1 axis and novel combined approaches to enhance immunotherapy of CRC by focusing on PD-L1.     

A Novel Molecular Design for a Hybrid Phage-DNA Construct Against DKK1

Nucleic acid immunization has recently exhibited a great promise for immunotherapy of various diseases. However, it is now clear that powerful strategies are imminently needed to improve their efficiency. In this regard, whole bacteriophage particles have been described as efficient DNA vaccine delivery vehicles, capable of circumventing the limitations of naked DNA immunization. Moreover, phage particles could be engineered to display specific peptides on their surfaces. Given these inherent characteristics of phages, we have designed a novel hybrid phage-DNA immunization vector using both M13 and pAAV plasmid elements. Following the construction and in vitro confirmation of the designed vectors, they were used for comparative mice immunization, carrying the same DNA sequence. The results indicated the efficacy of the designed hybrid phage particles, to elicit higher humoral immunity, in comparison to conventional DNA-immunization vectors (pCI). In light of these findings, it could be concluded that using adeno-associated virus (AAV) expression cassette along with displaying TAT peptide on the surface of the phage particle could be deemed as an appealing strategy to enhance the DNA-immunization and vaccination efficacy.     

Anti-CD37 targeted immunotherapy of B-Cell malignancies

CD37 is a member of tetra-spanning superfamily (characterized by their four transmembrane domains). It is one of the specific proteins for normal and malignant mature B cells. Anti CD37 monoclonal antibodies are reported to improve the overall survival in CLL. These therapeutics will increase the efficacy and reduce the toxicity in patients with both newly diagnosed and relapsed and refractory disease. Recent clinical trials have shown promising outcomes for these agents, administered both as monotherapy and in combination with standard chemotherapeutics. Long-term follow-up of combination regimens has even raised the question of whether the patients with CLL could be treated with intensive chemo-immunotherapy. In the present study, CD37 is introduced as an appealing target to treat B cell malignancies. The anti-CD37 antibodies as one of the most successful therapeutics against CD37 are introduced and the clinical outcomes of their exploitation are explained.