The recent viral infection disease pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in a global public health crisis. Iran, as one of the countries that reported over five million infected cases by September 2021, has been concerned with the urgent development of effective vaccines against SARS-CoV-2. In this paper, we report the results of a study on potency and safety of an inactivated SARS-CoV-2 vaccine candidate (FAKHRAVAC) in a preclinical study so as to confirm its potential for further clinical evaluation. Here, we developed a pilot-scale production of FAKHRAVAC, a purified inactivated SARS-CoV-2 virus vaccine candidate that induces neutralizing antibodies in Balb/c mice, guinea pigs, rabbits, and non-human primates (Rhesus macaques—RM). After obtaining ethical code of IR.IUMS.REC.1399.566, immunizations of animals were conducted by using either of three different vaccine dilutions; High (H): 10 μg/dose, Medium (M): 5 μg/dose, and Low (L): 1 μg/dose, respectively. In the process of screening for viral seeds, viral strains that resulted in the most severe clinical manifestation in patients have been isolated for vaccine development. The viral seed produced the optimal immunity against SARS-CoV-2 virus, which suggests a possible broader neutralizing ability against SARS-CoV-2 strains. The seroconversion rate at the H-, M-, and L-dose groups of all tested animals reached 100% by 28 days after immunization. These data support the eligibility of FAKHRAVAC vaccine candidate for further evaluation in a clinical trial.

Botulinum neurotoxin type A (BoNT/A) has been used as an injectable therapeutic agent for the treatment of some abnormal muscle contractions. In this study, TAT(47-57) peptide, a cell-penetrating peptide, was fused with the catalytic domain of BoNT/A for therapeutic purposes. HeLa and BE(2)-C cell lines were treated separately with purified TAT-BoNT/A(1-448) recombinant protein, and transduction of protein was analyzed by western blotting. Also, transcutaneous delivery through mouse skin surface was evaluated by immunohistochemistry. The in vitro catalytic activity of TAT-BoNT/A(1-448) was evaluated by HPLC. The presence of recombinant protein was detected in both of the cell lines as well as mouse skin cryosections after 60 and 120 min of incubation. The concentration of intracellular proteins was increased over time. HPLC analysis showed that this fusion protein has a biological activity 1.5 times as much as the full-length BoNT/A(1-448) protein. TAT-BoNT/A(1-448) fusion protein is biologically active and can transmit through living cells in vitro and in vivo successfully and more effectively compared with BoNT/A(1-448) protein as control.

Botulinum toxin type A can temporarily inhibit muscle contraction. Currently, physicians administer this toxin as a bio-drug in treatment of some muscle contraction disorders. TAT-BoNT/A (1-448) is a functional recombinant protein derived from botulinum toxin light chain. Unlike the full length botulinum toxin, TAT-BoNT/A (1-448) is a self-permeable molecule which can pass through biosurfaces so can be used as a topical therapeutic agent without injection. To maintain the functionality of TAT-BoNT/A , it is necessary to restore its normal folding upon expression and purification. In this study, we have investigated and optimized expression conditions for this novel recombinant protein. Under denaturing condition (1 mM IPTG, at 37 C), the chimeric protein was produced as inclusion body and required to be purified using denaturing agents (e.g. urea). Yet, lower incubation temperature (18 C) and less IPTG concentration (0.5 mM) induce a protein under native condition. In such condition, about 60% of the chimeric protein was expressed in soluble form.KEYWORDS cell-penetrating peptide; inclusion body; light chain of botulinum toxin type A; protein expression TAT-BoNT/A

Introduction: Antibiotic resistance has been reported as one of the world's most critical public health problems. Recent investigations have demonstrated that venom of some species of snakes have antimicrobial and anticancer activities. In this study, we investigated the antibacterial and anticancer effects of Persian horned viper venom. Antibacterial activity was examined on Escherichia coli, Bacillus subtilis and Staphylococcus aureus bacteria and antitumor effect was analyzed on human hepatocellular liver carcinoma cell line (HepG2). Materials and Methods: Bactericidal-activity of crude venom in concentrations of 6.25-400 μg/ml was performed using MTT reduction, minimum inhibitory concentration (MIC), agar-well diffusion and disc diffusion methods. Tetracycline (50 μg/ml) was used as standard antibiotic. Cytotoxic effect in HepG2 cell were measured by MTT reduction assay and confirmed with neutral uptake assay following exposure of cells with different concentrations of venom (50-400 μg/ml). Apoptotic effect was investigated using comet assay. Results: Our findings demonstrated that venom displays higher inhibitory effects against Gram-positive bacteria as compared to Gram-negative. Furthermore, venom showed anticancer activity on HepG2 cell line through induction of apoptosis and necrosis. Conclusion: This study showed that raw venom of Iranian horned viper has antibacterial and anti-cancer activity. These properties make venom of this viper a potential source for isolation of effective molecule(s) having antibacterial and antitumor activity.