Combination therapy with oncolytic virus and T cells or mRNA vaccine amplifies antitumor effects.

Antitumor therapies based on adoptively transferred T cells or oncolytic viruses have made significant progress in recent years, but the limited efficiency of their infiltration into solid tumors makes it difficult to achieve desired antitumor effects when used alone. In this study, an oncolytic virus (rVSV-LCMVG) that is not prone to induce virus-neutralizing antibodies was designed and combined with adoptively transferred T cells. By transforming the immunosuppressive tumor microenvironment into an immunosensitive one, in B16 tumor-bearing mice, combination therapy showed superior antitumor effects than monotherapy. This occurred whether the OV was administered intratumorally or intravenously. Combination therapy significantly increased cytokine and chemokine levels within tumors and recruited CD8+ T cells to the TME to trigger antitumor immune responses. Pretreatment with adoptively transferred T cells and subsequent oncolytic virotherapy sensitizes refractory tumors by boosting T-cell recruitment, down-regulating the expression of PD-1, and restoring effector T-cell function. To offer a combination therapy with greater translational value, mRNA vaccines were introduced to induce tumor-specific T cells instead of adoptively transferred T cells. The combination of OVs and mRNA vaccine also displays a significant reduction in tumor burden and prolonged survival. This study proposed a rational combination therapy of OVs with adoptive T-cell transfer or mRNA vaccines encoding tumor-associated antigens, in terms of synergistic efficacy and mechanism.

Micronanoparticled risedronate exhibits potent vaccine adjuvant effects.

Micro/Nano-scale particles are widely used as vaccine adjuvants to enhance immune response and improve antigen stability. While aluminum salt is one of the most common adjuvants approved for human use, its immunostimulatory capacity is suboptimal. In this study, we modified risedronate, an immunostimulant and anti-osteoporotic drug, to create zinc salt particle-based risedronate (Zn-RS), also termed particulate risedronate. Compared to soluble risedronate, micronanoparticled Zn-RS adjuvant demonstrated increased recruitment of innate cells, enhanced antigen uptake locally, and a similar antigen depot effect as aluminum salt. Furthermore, Zn-RS adjuvant directly and quickly stimulated immune cells, accelerated the formulation of germinal centers in lymph nodes, and facilitated the rapid production of antibodies. Importantly, Zn-RS adjuvant exhibited superior performance in both young and aged mice, effectively protecting against respiratory diseases such as SARS-CoV-2 challenge. Consequently, particulate risedronate showed great potential as an immune-enhancing vaccine adjuvant, particularly beneficial for vaccines targeting the susceptible elderly.

Precision and correlation of ED50 and endpoint titer method in measuring HPV vaccine immunogenicity.

Cervical cancer, the second leading cause of cancer-related deaths among women, is caused by human papillomavirus (HPV), a sexually transmitted virus. Vaccination is an effective preventive measure against viral infections and subsequent development of cervical cancer. Enzyme-linked immunosorbent assay (ELISA) is commonly used to measure specific binding antibody titers and assess the immunogenicity of test vaccines in preclinical models or clinical volunteers. Two methods of deriving titers, the endpoint titer (ET) and the effective dilution producing a median maximal effective fold of dilution (ED50) with a cut-off value, are widely used. For HPV, a pseudovirion-based neutralization assay (PBNA) is used to measure functional antibody titers. The ELISA binding titers and functional PBNA titers were found to be well-correlated for all nine HPV types tested in the vaccine, consistent with previous studies on HPV 16/18. Comparing the PBNA results with the two titration methods, the ED50 method showed higher precision and a closer correlation with PBNA results, both for individual types and pooled data analysis for all nine types. When comparing the titration results of the ET method based on a cut-off value with the ED50 method using all the data points across the dilution series, the ED50 method demonstrated better precision and a stronger correlation with PBNA results.

Protective immunity of largemouth bass immunized with immersed DNA vaccine against largemouth bass ulcerative syndrome virus.

To reduce the largemouth bass ulcer syndrome (LBUSV) aquatic economic losses, it must take effective preventive measures and coping strategies should be urgently investigated. In this research, the effects of a functionalized single-walled carbon nanotubes (SWCNTs) applied as a delivery vehicle for DNA vaccine administration in largemouth bass (Micropterus Salmoides) against LBUSV were studied. Our results showed that SWCNTs loaded with DNA vaccine induced a better protection to largemouth bass against LBUSV. We found more than 10 times increase in serum antibody levels, enzyme activities and immune-related genes (IL-6, IL-8, IFN-γ, IgM and TNF-α) expression, in the SWCNTs-pcDNA-MCP immunized groups compared with PBS group and the pure SWCNTs group. The survival rates for control group (PBS), pure SWCNTs groups (40 mg L-1), four pcDNA-MCP groups (5 mg L-1, 10 mg L-1, 20 mg L-1 and 40 mg L-1) and four SWCNTs-pcDNA-MCP groups (5 mg L-1, 10 mg L-1, 20 mg L-1 and 40 mg L-1) were 0%, 0%, 0%, 2.77%, 11.11%, 19.44%, 27.78%, 38.89%, 52.78% and 61.11%, respectively. Our results demonstrate that the SWCNTs-DNA vaccine can be used as a new method against LBUSV showing protection following challenge with LBUSV.

Optimization of the efficacy of a SWCNTs-based subunit vaccine against infectious spleen and kidney necrosis virus in mandarin fish.

Infectious spleen and kidney necrosis virus (ISKNV) cause a high mortality disease which brings substantial economic losses to the mandarin fish culture industry in China. This study was aimed at optimizing the efficacy of a SWCNTs-based immersion subunit vaccine (SWCNTs-M-MCP) which as a promising vaccine against ISKNV. Mandarin fish were vaccinated by immersion, then we designed an orthogonal experiment to optimize different parameters affecting vaccination such as immune duration of bath immunization, immune dose, and fish density when immunized. Our results showed that the highest relative percent survival (86.7%) was found in the group 6 with 8 h of immune duration, 20 mg/L of immune dose, and 8 fish per liter of fish density. And other immune responses (serum antibody production, enzyme activities, and immune-related genes expression) also demonstrated similar results. In addition, the expression of IRF-I in group 6 (8 h, 20 mg/L, 8 fish per liter) was significant extents, and about 16-folds increases were obtained than the control group at 21 d post-vaccination. And the highest specific antibody response was significantly increased (more than 4-folds) than control group which was found in group 6. The optimum immune duration, immune dose, and fish density of SWCNTs-M-MCP were 8 h, 20 mg/L, 8 fish per liter, respectively. Importantly, our results also showed that immune duration had the greatest effect on the immune response of our vaccine, followed by immune dose. The study reported herein provides a helpful reference for the effective use of vaccine in fish farming industry.

Immune efficacy of carbon nanotubes recombinant subunit vaccine against largemouth bass ulcerative syndrome virus.

Largemouth bass ulcerative syndrome virus (LBUSV) is an important virus induce the mortality of largemouth bass (Micropterus Salmoides). In this study, we reported a single-walled carbon nanotubes (SWCNTs) containing LBUSV major capsid protein (MCP) subunit vaccine (SWCNTs-MCP) which was evaluated for its protective effect on largemouth bass by immersion immunization. We found an elevation in serum antibody levels, enzyme activities, complement C3 content and immune-related genes (IgM, TGF-ß, IL-1ß, IL-8, TNF-α and CD4) expression, in the SWCNTs-MCP immunized groups compared with the pure MCP group. The survival rates for control group, pure MCP protein groups (40 mg L-1) and four SWCNTs-MCP groups (5 mg L-1, 10 mg L-1, 20 mg L-1 and 40 mg L-1) were 0%, 27.78%, 30.56%, 50.00%, 66.67% and 80.56%, respectively. The results suggests that with the assistance of SWCNTs, the immune protection of the SWCNTs-MCP group (40 mg L-1) increased up 52.78%-80.1% compared with pure MCP group (40 mg L-1). Our results demonstrate that the single-walled carbon nanotube subunit vaccine can be used as a new immunization method against LBUSV showing protection following challenge with LBUSV. Taken together, our results demonstrate that the single-walled carbon nanotube subunit vaccine can be used as a new method against LBUSV and have a high immune protection during the largemouth bass farm.

Carbon nanotubes-loaded subunit vaccine can increase protective immunity against rhabdovirus infections of largemouth bass (Micropterus Salmoides).

Micropterus Salmoides rhabdovirus (MSRV), as a common aquatic animal virus, can cause lethal and epidemic diseases in the cultivation of largemouth bass. In this study, we reported a kind of immersion single-walled carbon nanotubes-loaded subunit vaccine which composited by glycoprotein (G) of MSRV, and evaluated its protective effect on largemouth bass. The results showed that a stronger immune response including serum antibody levels, enzyme activities (superoxide dismutase, acid phosphatase, alkaline phosphatase and total antioxidant capacity), complement C3 content and immune-related genes (IgM, TGF-ß, IL-1ß, IL-8, TNF-α, CD4) expression can be induced obviously with single-walled carbon nanotubes-glycoprotein (SWCNTs-G) groups compared with G groups when largemouth bass were vaccinated. After bath immunization with G or SWCNTs-G for 28 days, fish were challenged with a lethal dose of MSRV. The survival rates for control group (PBS), SWCNTs group (40 mg L-1), pure G protein groups (40 mg L-1) and three SWCNTs-G groups (5 mg L-1, 10 mg L-1 and 40 mg L-1) were 0%, 0%, 39.5%, 36.7%, 43.6%and 70.1%, respectively. Importantly, with the assistance of SWCNTs, the immune protective rate of the SWCNTs-G group (40 mg L-1) increased by approximately 30.6%. This study suggested that SWCNTs-G is a promising immersion subunit vaccine candidate against the death caused by MSRV.

Immersion vaccination of Mandarin fish Siniperca chuatsi against infectious spleen and kidney necrosis virus with a SWCNTs-based subunit vaccine.

Infectious spleen and kidney necrosis virus (ISKNV) cause a high mortality disease which lead to significant economic loss on mandarin fish in China. There is no effective drug or vaccine against this fatal disease at present. Meanwhile, many drugs and vaccines had no effect in many cases account of several impenetrable barriers (cell, skin and gastrointestinal tract). Here we reported an immersion subunit vaccine system (SWCNTs-MCP) encoding MCP gene of ISKNV based on single-walled carbon nanotubes (SWCNTs). To evaluate its efficacy against ISKNV, we found a stronger and longer duration immune response (serum antibody production, enzyme activities and immune-related genes expression) can be induced in fish vaccinated with SWCNTs-MCP in comparison with those vaccinated with MCP alone. Importantly, SWCNTs can increase the immune protective effect of naked subunit vaccine by ca. 23.8%. Thereby, this study demonstrates that SWCNTs as a promising carrier for subunit vaccine might be used to vaccinate large-scale juvenile mandarin fish by bath administration approach.