Preclinical Assessment of Immunogenicity and Protectivity of Novel ROR1 Fusion Proteins in a Mouse Tumor Model

The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a new tumor associated antigen (TAA) which is overexpressed in several hematopoietic and solid malignancies. The present study aimed to produce and evaluate different fusion proteins of mouse ROR1 (mROR1) to enhance immunogenicity and protective efficacy of ROR1. Four ROR1 fusion proteins composed of extracellular region of mROR1, immunogenic fragments of TT as well as Fc region of mouse IgG2a were produced and employed to immunize Balb/C mice. Humoral and cellular immune responses and anti-tumor effects of these fusion proteins were evaluated using two different syngeneic murine ROR1+ tumor models. ROR1-specific antibodies were induced in all groups of mice. The levels of IFN-γ, IL-17 and IL-22 cytokines in culture supernatants of stimulated splenocytes were increased in all groups of immunized mice, particularly mice immunized with TT-mROR1-Fc fusion proteins. The frequency of ROR1-specific CTLs was higher in mice immunized with TT-mROR1-Fc fusion proteins. Finally, results of tumor challenge in immunized mice showed that immunization with TT-mROR1-Fc fusion proteins completely inhibited ROR1+ tumor cells growth in two different syngeneic tumor models until day 120 post tumor challenge. Our preclinical findings, for the first time, showed that our fusion proteins could be considered as a potential candidate vaccine for active immunotherapy of ROR1-expressing malignancies

Anti-inflammatory and tissue repair effect of cinnamaldehyde and nano cinnamaldehyde on gingival fibroblasts and macrophages

Abstract Background Recurrent aphthous stomatitis has a complex and inflammatory origin. Among the great variety of medications it is increasingly common to use herbal medicines due to the adverse side effects of chemical medications. Considering the anti-inflammatory properties of cinnamaldehyde and the lack of studies related to the effectiveness of its nano form; This study investigates the effect of cinnamaldehyde and nano cinnamaldehyde on the healing rate of recurrent aphthous stomatitis lesions. Methods In a laboratory experiment, cinnamaldehyde was converted into niosomal nanoparticles. The niosome vesicles diameter and polydispersity index were measured at 25°C using a dynamic light scattering (DLS) Mastersizer 2000 (Malvern Panalytical technologies: UK) and Zetasizer Nano ZS system (Malvern Instruments Worcestershire: UK). After characterizing these particles, the (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) [XTT] assay was used to assess the toxicity of cinnamaldehyde and nano cinnamaldehyde on gingival fibroblast (HGF) and macrophage (THP-1) cells. By determining the release of TNF-α, IL-6, and TGF-β cytokines using ELISA kits, the level of tissue repair and anti-inflammatory capabilities of these two substances were evaluated. Results The size and loading rate of the cinnamaldehyde nanoparticles were established after its creation. The optimized nanovesicle exhibited the following characteristics: particle size of 228.75 ± 2.38 nm, PDI of 0.244 ± 0.01, the zeta potential of -10.87 ± 1.09 mV and the drug encapsulation percentage of 66.72 ± 3.93%. PDIs range was between 0.242–0.274. The zeta potential values at 25°C were from -2.67 to -12.9 mV. The results of the XTT test demonstrated that nano cinnamaldehyde exhibited dose-dependent toxicity effects. Moreover, nano cinnamaldehyde released more TGF-β and had better reparative effects when taken at lower concentrations than cinnamaldehyde. Conclusion Nano cinnamaldehyde and cinnamaldehyde are effective in repairing tissue when used in non-toxic amounts. After confirmation in animal models, it is envisaged that these substances can be utilized to treat recurrent aphthous stomatitis

Comparison of neutralization potency across passive immunotherapy approaches as potential treatments for emerging infectious diseases

The use of passive immunotherapy, either as plasma or purified antibodies, has been recommended to treat the emerging infectious diseases (EIDs) in the absence of alternative therapeutic options. Here, we compare the neutralization potency of various passive immunotherapy approaches designed to provide the immediate neutralizing antibodies as potential EID treatments. To prepare human plasma and purified IgG, we screened and classified individuals into healthy, convalescent, and vaccinated groups against SARS-CoV-2 using qRT-PCR, anti-nucleocapsid, and anti-spike tests. Moreover, we prepared purified IgG from non-immunized and hyperimmunized rabbits against SARS-CoV-2 spike protein. Human and rabbit samples were used to evaluate the neutralization potency by sVNT. All vaccinated and convalescent human plasma and purified IgG groups, as well as purified IgG from hyperimmunized rabbits, had significantly greater levels of spike-specific antibodies than the control groups. Furthermore, when compared to the other groups, the purified IgG from hyperimmunized rabbits exhibited superior levels of neutralizing antibodies, with an IC50 value of 2.08 μg/ml. Additionally, our results indicated a statistically significant positive correlation between the neutralization IC50 value and the positive endpoint concentration of spike-specific antibodies. In conclusion, our study revealed that purified IgG from hyperimmunized animals has greater neutralization potency than other passive immunotherapy methods and may be the most suitable treatment of critically ill patients in EIDs

Blockade of HIF-1α and STAT3 by hyaluronate-conjugated TAT- chitosan-SPION nanoparticles loaded with siRNA molecules prevents tumor growth

HIF-1α and STAT3 are two of the critical factors in the growth, proliferation, and metastasis of cancer cells and play a crucial role in inhibiting anti-cancer immune responses. Therefore, we used superparamagnetic iron oxide (SPION) nanoparticles (NPs) coated with thiolated chitosan (ChT) and trimethyl chitosan (TMC) and functionalized with hyaluronate (H) and TAT peptide for delivery of siRNA molecules against STAT3 and HIF-1α to cancer cells both in vivo and in vitro. The results indicated that tumor cell transfection with siRNAencapsulated NPs robustly inhibited proliferation and migration and induced apoptosis in tumor cells. Furthermore, simultaneous silencing of HIF-1α and STAT3 significantly repressed cancer development in two different tumor types (4T1 breast cancer and CT26 colon cancer) which were associated with upregulation of cytotoxic T lymphocytes and IFN-γ secretion. The findings suggest inhibiting the HIF-1α/ STAT3 axis by SPION-TMC-ChT-TAT-H NPs as an effective way to treat cancer

Dual Blockade of PD-1 and LAG3 Immune Checkpoints Increases Dendritic Cell Vaccine Mediated T Cell Responses in Breast Cancer Model

Purpose Increasing the efficiency of unsuccessful immunotherapy methods is one of the most important research fields. Therefore, the use of combination therapy is considered as one of the ways to increase the effectiveness of the dendritic cell (DC) vaccine. In this study, the inhibition of immune checkpoint receptors such as LAG3 and PD-1 on T cells was investigated to increase the efficiency of T cells in response to the DC vaccine. Methods We used trimethyl chitosan-dextran sulfate-lactate (TMC-DS-L) nanoparticles (NPs) loaded with siRNA molecules to quench the PD-1 and LAG3 checkpoints’ expression. Results Appropriate physicochemical characteristics of the generated NPs led to efficient inhibition of LAG3 and PD-1 on T cells, which was associated with increased survival and activity of T cells, ex vivo. Also, treating mice with established breast tumors (4T1) using NPs loaded with siRNA molecules in combination with DC vaccine pulsed with tumor lysate significantly inhibited tumor growth and increased survival in mice. These ameliorative effects were associated with increased anti-tumor T cell responses and downregulation of immunosuppressive cells in the tumor microenvironment and spleen. Conclusion These findings strongly suggest that TMC-DS-L NPs loaded with siRNA could act as a novel tool in inhibiting the expression of immune checkpoints in the tumor microenvironment. Also, combination therapy based on inhibition of PD-1 and LAG3 in combination with DC vaccine is an effective method in treating cancer that needs to be further studied