Immunogenicity of adenovirus and DNA vaccines co-expressing P39 and lumazine synthase proteins of Brucella abortus in BALB/c mice.

Brucella poses a great threat to animal and human health. Vaccination is the most promising strategy in the effort to control Brucella abortus (B. abortus) infection, but the currently used live vaccines interfere with diagnostic tests and could potentially result in disease outbreak. Therefore, new subunit vaccines and combined immunization strategies are currently under investigation. In this study, immunogenicity and protection ability of a recombinant adenovirus and plasmid DNA vaccine co-expressing P39 and lumazine synthase proteins of B. abortus were evaluated based on the construction of the two molecular vaccines. Four immunization strategies (single adenovirus, single DNA, adenovirus/DNA, DNA/adenovirus) were investigated. The results showed that the immunization strategy of DNA priming followed by adenovirus boosting induced robust humoral and cellular immune responses, and it significantly reduced the numbers of B. abortus in a mouse model. These results suggest that it could be a potential antigen candidate for development of a new subunit vaccine against B. abortus infection.

Comparison of the adipogenesis in intramuscular and subcutaneous adipocytes from Bamei and Landrace pigs.

Fat deposition is a complex process involving proliferation, differentiation, and lipogenesis of adipocytes. Bamei and Landrace are considered to represent fat- and lean-type pig breeds. Subcutaneous (SC) and intramuscular (IM) pre-adipocytes were cultured to compare the proliferation and lipogenesis in these breeds. The differentiated adipocytes were exposed to glucose or insulin to evaluate their effects on lipogenesis and lipogenic gene expression. Pre-adipocytes proliferated dramatically faster in SC vs. IM cells, and in Bamei vs. Landrace breeds. Lipogenesis and lipogenic gene expression had a greater increase in Bamei than in Landrace, and in SC vs. IM in the process of differentiation. Glucose markedly promoted lipogenesis and lipogenic gene expression in differentiated adipocytes. The stimulation of high-glucose levels on lipogenesis and ChREBP and lipogenic gene expression was higher in SC than IM adipocytes, and in Bamei vs. Landrace. Insulin largely increased SREBP-1c expression, however it modestly stimulated lipogenesis and lipogenic gene expression, and there was no difference between cell populationsor between breeds. These data demonstrated that regional and varietal differences obviously existed in the development of porcine adipocytes. The proliferation and differentiation capacity of pre-adipocytes, and the adipocyte lipogenesis stimulated by glucose, are stronger in Bamei than Landrace, and in SC vs. IM adipocytes independent of breed.

[Studies on isolation, purification and antibacterial activities of beta-defensin in Yak neutrophils].

AIM: To isolate and purify beta-defensin from the neutrophils of Yak. METHODS: The method of percoll gradient centrifugation was employed to purify neutrophils from Yak peripheral blood. The crude extraction from Yak neutrophils was isolated respectively through a way of extraction by 50 mL/L acetic acid, acid soluble extract of Yak neutrophils was obtained. Then it was further purified by Bio-Gel P-10 Polyacrylamide gel filtration and RP-HPLC, and 9 out of 22 apices showed antibacterial activity. 9 apices showing antibacterial activity were selected to be analyzed by mass spectrograph.The antibacterial activities of the extracts from every step were analyzed by agarose radial diffusion assay. RESULTS: The molecular weight of the purified Yak BNBD-1-3 was determined to be 4.2, 4.6 and 4.8 kDa by mass spectrograph. BNBD-1-3 from Yak neutrophils were able to effectively kill Escherichia coli, Staphylococcus aureus and Bacillus subtilis. CONCLUSION: Yak neutrophils have beta-defensin which have broad-spectrum antimicrobial activity, Yak defensin has an important part in innate immunity.

[Establishing and identifying insulin resistance 3T3-L1 adipocytes cell model].

OBJECTIVE: To establish insulin-resistant 3T3-L1 adipocytes cell model. METHODS: 3T3-L1 preadipocytes were cultured and induced to differentation. We established insulin resistant 3T3-L1 induced by dexamethasone and determined the change of glucose concentration in cell culture. RESULTS: In high glucose DMEM culture media, the glusose concentration significantly decreased. Achieved the peak of insulin-resisitant at the 96th hour induced by dexamethasone, and at this time compared with the blank the mRNA expression of Resistin of the model step up about three times. CONCLUSION: 3T3-L1 adipocyte exposed to 1 micromol/L dexamethasone for 24 hours are able to induce a state of insulin resistance which can be maintained for 216 hours.