Fiber manipulation and post-assembly nanobody conjugation for adenoviral vector retargeting through SpyTag-SpyCatcher protein ligation

For adenoviruses (Ads) to be optimally effective in cancer theranostics, they need to be retargeted toward target cells and lose their natural tropism. Typically, this is accomplished by either engineering fiber proteins and/or employing bispecific adapters, capable of bonding Ad fibers and tumor antigen receptors. This study aimed to present a simple and versatile method for generating Ad-based bionanoparticles specific to target cells, using the SpyTag-SpyCatcher system. The SpyTag peptide was inserted into the HI loop of fiber-knob protein, which could act as a covalent anchoring site for a targeting moiety fused to a truncated SpyCatcher (SpyCatcherΔ) pair. After confirming the presence and functionality of SpyTag on the Ad type-5 (Ad5) fiber knob, an adapter molecule, comprising of SpyCatcherΔ fused to an anti-vascular endothelial growth factor receptor 2 (VEGFR2) nanobody, was recombinantly expressed in Escherichia coli and purified before conjugation to fiber-modified Ad5 (fmAd5). After evaluating fmAd5 detargeting from its primary coxsackie and adenovirus receptor (CAR), the nanobody-decorated fmAd5 could be efficiently retargeted to VEGFR2-expressing 293/KDR and human umbilical vein endothelial (HUVEC) cell lines. In conclusion, a plug-and-play platform was described in this study for detargeting and retargeting Ad5 through the SpyTag-SpyCatcher system, which could be potentially applied to generate tailored bionanoparticles for a broad range of specific targets; therefore, it can be introduced as a promising approach in cancer nanotheranostics

Efficacy of levamisole with standard care treatment vs. standard care in clinical presentations of non-hospitalized patients with COVID-19: a randomized clinical trial

Objective: The aim of this study was to evaluate the influence of adding a 10-day course of levamisole (LVM) to the standard care compared with standard care alone, on the clinical status of COVID-19 patients with mild to moderate disease. Methods:  In this randomized open-label trial, we enrolled non-hospitalized patients with mild to moderate COVID-19 at nine health centers in Tehran province, Iran, in 2021. Patients were randomly assigned to receive a 10-day course of LVM with standard care (n=185) or standard care alone (n=180) in a 1:1 ratio. On days 1 to 10, LVM was administered orally at a dosage of 50 mg. The participants were called and followed on days 1, 3, 5, 7, 9, and 14. The measured parameters were general health condition, hospitalization rate, signs and symptoms, and adverse events. The generalized estimating equations model was used for analysis. Results: Among 507 randomized patients, 473 patients started the experiment and received LVM plus standard care or received the standard care alone; 385 patients included in the analysis; 346 (98%) patients completed the trial. The median age of the patients was 40 years [IQR: 32-50.75]; and ‎201 (55.1%)‎ patiens were male. The mean age, sex ratio, and frequency of the underlying diseases of the patients in the two study groups had no ‎statistically significant differences (P>0.05). Compared to the control group, LVM improved the general health condition of the patients (B=-0.635; 95% CI: -0.041,-0.329; P<0.001). Patients receiving LVM compared with standard care group had significantly lower odds of developing fever (OR=0.260; 95% CI: 0.11‎‎3‎,0.59‎‎9‎; P=0.002), chills (OR=0.223; 95% CI:‎‎ 0.07‎‎6,‎0.64‎‎8‎; P= 0.006), fatigue (OR=0.576; 95% CI:‎ 0.34‎‎6,‎0.96‎‎0‎‎; P=0.034), and myalgia (OR=0.54‎‎4‎; 95% CI:‎ 0.31‎‎7‎,0.93‎‎2‎‎; P=0.027). No significant difference was observed in the rate of hospitalization. Although the intervention group had greater adverse effects than the control group, the difference was not statistically significant. Conclusion: Findings of this study suggest that LVM has clinical benefits in improving patients’ health condition with mild to moderate COVID-19

Cancer Vaccines for Triple-Negative Breast Cancer: A Systematic Review

Triple-negative breast cancer (TNBC) is the subtype of breast cancer with the poorest outcomes, and is associated with a high risk of relapse and metastasis. The treatment choices for this malignancy have been confined to conventional chemotherapeutic agents, due to a lack of expression of the canonical molecular targets. Immunotherapy has been recently changing the treatment paradigm for many types of tumors, and the approach of evoking active immune responses in the milieu of breast tumors through cancer vaccines has been introduced as one of the most novel immunotherapeutic approaches. Accordingly, a number of vaccines for the treatment or prevention of recurrence have been developed and are currently being studied in TNBC patients, while none have yet received any approvals. To elucidate the efficacy and safety of these vaccines, we performed a systematic review of the available literature on the topic. After searching the PubMed, Scopus, Web of Science, Embase, Cochrane CENTRAL, and Google Scholar databases, a total of 5701 results were obtained, from which 42 clinical studies were eventually included based on the predefined criteria. The overall quality of the included studies was acceptable. However, due to a lack of reporting outcomes of survival or progression in some studies (which were presented as conference abstracts) as well as the heterogeneity of the reported outcomes and study designs, we were not able to carry out a meta-analysis. A total of 32 different vaccines have so far been evaluated in TNBC patients, with the majority belonging to the peptide-based vaccine type. The other vaccines were in the cell or nucleic acid (RNA/DNA)-based categories. Most vaccines proved to be safe with low-grade, local adverse events and could efficiently evoke cellular immune responses; however, most trials were not able to demonstrate significant improvements in clinical indices of efficacy. This is in part due to the limited number of randomized studies, as well as the limited TNBC population of each trial. However, due to the encouraging results of the currently published trials, we anticipate that this strategy could show its potential through larger, phase III randomized studies in the near future

Table1_Fiber manipulation and post-assembly nanobody conjugation for adenoviral vector retargeting through SpyTag-SpyCatcher protein ligation.docx

For adenoviruses (Ads) to be optimally effective in cancer theranostics, they need to be retargeted toward target cells and lose their natural tropism. Typically, this is accomplished by either engineering fiber proteins and/or employing bispecific adapters, capable of bonding Ad fibers and tumor antigen receptors. This study aimed to present a simple and versatile method for generating Ad-based bionanoparticles specific to target cells, using the SpyTag-SpyCatcher system. The SpyTag peptide was inserted into the HI loop of fiber-knob protein, which could act as a covalent anchoring site for a targeting moiety fused to a truncated SpyCatcher (SpyCatcherΔ) pair. After confirming the presence and functionality of SpyTag on the Ad type-5 (Ad5) fiber knob, an adapter molecule, comprising of SpyCatcherΔ fused to an anti-vascular endothelial growth factor receptor 2 (VEGFR2) nanobody, was recombinantly expressed in Escherichia coli and purified before conjugation to fiber-modified Ad5 (fmAd5). After evaluating fmAd5 detargeting from its primary coxsackie and adenovirus receptor (CAR), the nanobody-decorated fmAd5 could be efficiently retargeted to VEGFR2-expressing 293/KDR and human umbilical vein endothelial (HUVEC) cell lines. In conclusion, a plug-and-play platform was described in this study for detargeting and retargeting Ad5 through the SpyTag-SpyCatcher system, which could be potentially applied to generate tailored bionanoparticles for a broad range of specific targets; therefore, it can be introduced as a promising approach in cancer nanotheranostics.</p