Newcastle disease (ND) is a highly contagious avian disease, causing considerable economic losses to the poultry industry. To obtain a safe, inexpensive, and effective ND vaccine to meet the international trade requirements of differentiating infected from vaccinated animals (DIVA), here we report the production of Oryza sativa recombinant fusion (F) protein in stably transformed transgenic rice seeds via agroinfiltration. The F protein expression level was enhanced 3.6-fold with a genetic background in low glutelin. Inoculation of plant-produced F antigen into Specific Pathogen Free (SPF) chickens markedly elicited neutralizing antibody responses against homologous and heterologous ND virus strains. Two doses of 4.5 μg fully protected chickens from a lethal ND challenge without any clinical symptoms. The mean weight gain of F protein-immunized chickens within 15 days after challenge was significantly higher than that of traditional whole virus vaccine-immunized chickens, thereby obtaining higher economic benefits. Moreover, the sera from the chickens vaccinated with the plant-produced F vaccine did not show reactivity in an immunochromatographic strip targeting the haemagglutinin-neuraminidase protein (HN) protein, and DIVA could be achieved within 10 minutes. Our results demonstrate that the plant-derived F vaccine along with immunochromatographic strips could be useful in the implementation of an NDV eradication program.

African swine fever (ASF), the highly lethal swine infectious disease caused by the African swine fever virus (ASFV), is a great threat to the swine industry. There is no effective vaccine or diagnostic method to prevent and control this disease currently. The p30 protein of ASFV is an important target for serological diagnosis, expressed in the early stage of viral replication and has high immunogenicity and sequence conservatism. Here, the CP204L gene was cloned into the expression vector pET-30a (+), and the soluble p30 protein was successfully expressed in the E. coli prokaryotic expression system and then labeled with horseradish peroxidase (HRP) to be the enzyme-labeled antigen. Using the purified recombinant p30 protein, a double-antigen sandwich ELISA for ASFV antibody detection was developed. This method exhibits excellent specificity, sensitivity and reproducibility in clinical sample detection with lower cost and shorter production cycles. Taken together, this study provides technical support for antibody detection for ASFV.

African swine fever (ASF) is an acute, virulent, and highly fatal infectious disease caused by the African swine fever virus (ASFV). There is no effective vaccine or diagnostic method to prevent and control this disease currently, which highlights the significance of ASF early detection. In this study, we chose an early antigen and a late-expressed antigen to co-detect the target antibody, which not only helps in early detection but also improves accuracy and sensitivity. CP204L and B602L were successfully expressed as soluble proteins in an Escherichia coli vector system. By optimizing various conditions, a dual-antigen indirect ELISA for ASFV antibodies was established. The assay was non-cross-reactive with antibodies against the porcine reproductive and respiratory syndrome virus, classical swine fever virus, porcine circovirus type 2, and pseudorabies virus. The maximum serum dilution for detection of ASFV-positive sera was 1:1600. The intra-batch reproducibility coefficient of variation was <5% and the inter-batch reproducibility coefficient of variation was <10%. Compared with commercial kits, the dual-antigen indirect ELISA had good detection performance. In conclusion, we established a detection method with low cost, streamlined production process, and fewer instruments. It provides a new method for the serological diagnosis of ASF.

Efficient eradication of cancer cells and enhanced tumor accumulation of drug via immune cells represent promising strategies for cancer treatment, yet they remain significant challenges. Inspired by neutrophils (NEs), we designed a novel nano-regulator (OMV@PCB NPs) to improve cancer therapy through polarizing NEs into anti-tumor N1 phenotype and photodynamic therapy (PDT)-assisted NEs hitchhiking delivery. OMV@PCB NPs were constructed by encapsulating Ce6 and SB525334 (TGF-β inhibitor) within PLGA nanoparticles, which were subsequently camouflaged with bacteria outer membrane vesicles (OMVs). Beyond inducing ROS generation under light irradiation to kill tumor cells, OMV@PCB NPs could effectively hitchhike NEs to enhance tumor accumulation based on PDT-assisted NEs recruitment. Encouragingly, SB525334, a TGF-β inhibitor in OMV@PCB NPs, could significantly polarize NEs into anti-tumor N1 phenotype, which could not only promote neutrophil elastase (ELANE) release to selectively eliminate cancer cells, but also elevate anticancer immunity by reversing the immunosuppressive tumor microenvironment, thereby achieving effective immuno-photodynamic therapy against tumor growth. This study offers a prospective avenue for enhancing cancer therapy.

Among various pathogens, viruses pose significant threats to the livestock and poultry industry, resulting in substantial annual costs due to production losses and vaccination. The MHC-I presentation pathway is a crucial surveillance mechanism for preventing viral infections. Consequently, many viruses have evolved sophisticated strategies to inhibit the presentation of viral peptides by MHC-I to CD8⁺ T-cells, thereby evading the immune system. Understanding the mechanisms that suppress the MHC-I pathway and identifying specific binding peptides are essential for comprehending viral immune evasion and developing effective animal vaccines. This review summarizes the viral strategies for evading immune recognition, including the inhibition of MHC-I molecules synthesis, degradation, transport, and assembly, which affect MHC-I surface expression during viral infections. We also present evidence that MHC-I surface expression is frequently lost during numerous viral infections in livestock and poultry and offer new insights into the underlying mechanisms through which viruses inactivate the MHC-I antigen presentation pathway. Collectively, these advanced findings on viral evasion from the MHC-I pathway could inform the development of more effectives strategies to restore immunological control over viral infections and improve vaccines for the livestock and poultry industry.

Zearalenone (ZEN), a stable mycotoxin with estrogenic activity produced by various Fusarium species, poses a serious food safety risk. To facilitate the rapid, sensitive, on-site detection of ZEN in maize and ensure consumer dietary safety, a colloidal gold immunochromatographic assay (CG-ICA) based on a monoclonal antibody was established. ZEN was converted via oxime derivatization into hapten ZAN-O, which was conjugated to a carrier protein to prepare an immunogen for producing a highly specific and sensitive monoclonal antibody. Then, the antibody was conjugated into colloidal gold nanoparticles (AuNPs) and used as capture bioprobes of the CG-ICA test strip. The highly sensitive and specific detection platform was established through systematic optimization of pH value, coating antigen concentration, antibody-labeling dosage, incubation time, and strip assembly conditions. Under optimized conditions, the strip exhibited a detection limit of 11.79 pg/mL and an IC₅₀ of 99.06 pg/mL, with a linear detection range of 13.40–732.48 pg/mL. In addition, the anti-interference capability assay demonstrated that the developed test strip possessed excellent specificity. In spiked maize samples, the CG-ICA test strip demonstrated recoveries ranging from 85.36% to 98.86%, with relative standard deviations (RSDs) below 10%. Thus, the CG-ICA strip provides a rapid, sensitive, and robust on-site tool for ZEN screening in maize, and can be adapted to other hazards by simply switching the antibody.