The interferon (IFN) pathway plays an essential role in the innate immune response following viral infections and subsequent shaping of adaptive immunity. Infections with influenza A viruses (IAV) activate the IFN pathway after the recognition of pathogen-specific molecular patterns by respective pattern recognition receptors. The IFN regulatory factors IRF3 and IRF7 are key players in the regulation of type I and III IFN genes. In this study, we analyzed the role of IRF3 and IRF7 for the host response to IAV infections in Irf3^-/-, Irf7^-/-, and Irf3^-/-Irf7^-/- knockout mice. While the absence of IRF3 had only a moderate impact on IFN expression, deletion of IRF7 completely abolished IFNα production after infection. In contrast, lack of both IRF3 and IRF7 resulted in the absence of both IFNα and IFNβ after IAV infection. In addition, IAV infection of double knockout mice resulted in a strong increase of mortality associated with a massive influx of granulocytes in the lung and reduced activation of the adaptive immune response.

Planktons are a major component of food web structure in aquatic ecosystems. Their distribution and community structure are driven by the combination and interactions between physical, chemical, and biological factors within the environment. In the present study, water quality and the community structure of phytoplankton and zooplankton were monthly investigated from January to December 2015 at 11 sampling sites along the gradient course of the Day River (Red River Delta, northern Vietnam). The study demonstrated that the Day River was eutrophic with the average values of total phosphorus concentration 0.17 mg/L, total nitrogen concentration 1.98 mg/L, and Chl a 54 μg/L. Microscopic plankton analysis showed that phytoplankton comprised 87 species belonging to seven groups in which Chlorophyceae, Bacillariophyceae, and Cyanobacteria accounted for the most important constituents of the river's phytoplankton assemblage. A total 53 zooplankton species belonging to three main groups including Copepoda, Cladocera, and Rotatoria were identified. Plankton biomass values were greatest in rainy season (3002.10-3 cell/L for phytoplankton and 12.573 individuals/m for zooplankton). Using principal correspondence and Pearson correlation analyses, it was found that the Day River was divided into three main site groups based on water quality and characteristics of plankton community. Temperature and nutrients (total phosphorus and total nitrogen) are key factors regulating plankton abundance and distribution in the Day River.

Vietnam is one of the countries most affected worldwide by the highly pathogenic avian influenza (HPAI) virus, which caused enormous economic loss and posed threats to public health. Over nearly two decades, with the antigenic changes in the diversified H5Ny viruses, the limited protective efficacy of the available vaccines was encountered. Therefore, it is necessary to approach a technology platform for the country to accelerate vaccine production that enables quick response to new influenza subtypes. This study utilized a powerful reverse genetics technique to successfully generate a recombinant H5N1 vaccine strain (designated as IBT-RG02) containing two surface proteins (haemagglutinin (HA) and neuraminidase (NA)) from the HPAI H5N1 (A/duck/Vietnam/HT2/2014(H5N1)) of the dominant clade 2.3.2.1c in Vietnam during 2012–2014. Importantly, the IBT-RG02 vaccine candidate has elicited high antibody titres in chickens (geometric mean titre (GMT) of 6.42 and 6.92, log2 on day 14 and day 28 p.i., respectively). To test the efficacy, immunized chickens were challenged with the circulating virulent strains. As results, there was a high protection rate of 91.6% chickens against the virulent A/DK/VN/Bacninh/NCVD-17A384/2017 of the same clade and a cross-protection of 83.3% against A/duck/TG/NAVET(3)/2013 virus of clade 1.1. Our promising results showed that we can independently master the reverse genetics technology for generation of highly immunogenic vaccine candidates, and henceforth, it is a timely manner to reformulate avian influenza virus vaccines against variable H5 clade HPAI viruses in Vietnam.

Bá bệnh (Eurycoma longifolia Jack) là loại thảo dược dùng điều trị bệnh sốt rét, ung thư, tiểu đường, rối loạn chức năng tình dục và tăng cường sức khỏe ở nam giới. Năm 2012, chúng tôi đã báo cáo phương pháp tạo rễ tơ của cây Bá bệnh với mục đích để tạo nguồn nguyên liệu ổn định, đáp ứng nhu cầu làm thuốc. Trong bài báo này, chúng tôi khảo sát hoạt tính sinh học của cao chiết methanol rễ tơ và rễ tự nhiên cây Bá bệnh. Kết quả cho thấy cao chiết methanol rễ tơ và rễ tự nhiên ức chế sản xuất cytokine gây viêm IL-6 kích thích bởi Lipopolysaccharide (LPS) ở dòng tế bào THP-1 với IC50 tương ứng là 3,6 và 6,6 (µg/ml). Cao chiết methanol rễ tơ và rễ tự nhiên có hoạt tính gây độc tế bào ung thư ở mức trung bình trên các dòng tế bào HepG2, LU-1, MCF-7 với IC50­ tương ứng là 77,4, 61,1, 88,2 (µg/ml) và 63,8, 46,2, 54,8 (µg/ml). Tuy nhiên, cả hai loại cao chiết nghiên cứu đều không có khả năng ức chế peroxidation lipid (IC50­ > 100).

Porcine epidemic diarrhea (PED), caused by the Porcine epidemic diarrhea virus (PEDV), is an acute, highly contagious disease of pigs of all ages, especially piglets under one week old, with the mortality rate reaching 95–100%. Developing an effective vaccine against PEDV in Vietnam is urgent. Spike protein containing S1 and S2 subunits is considered the main target for vaccine development, and the S2 subunit contains immunodominant neutralizing epitopes of PEDV. To date, the expression of S2 protein in plants has not been reported and evaluated. In this study, the gene encoding the S2 subunit of a PEDV strain belonging to genotype 2a was amplified, sequenced, and inserted in a pRTRA vector containing the GCN4pII (pII) motif. The plant expression cassette containing S2-pII was then inserted into the pCB301 vector. The Agrobacterium tumefaciens harboring the pCB301-S2-pII vector was transformed into Nicotiana benthamiana leaves via agroinfiltration. The accumulation level of S2-pII protein in tobacco leaves was semi-quantified by Western blot, accounting for approximately 86.7 mg/kg of fresh leaves and 1.47% total soluble protein, which was 294-fold higher than the accumulation level of S1-pII protein in our previous publication. S2-pII protein was successfully purified by immobilized metal affinity chromatography (IMAC). The oligomeric state of S2-pII protein was characterized by size exclusion chromatography (SEC). The S2-pII protein was determined to be a multimer protein with a high molecular weight. These results are the basis for more extended studies to develop a plant-based S2 vaccine against PEDV infection.

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