This study constructed a porcine reproductive and respiratory syndrome virus(PRRSV)NADC30-like strain GP3 recombinant adenovirus vector vaccine through in vitro homologous re-combination to explore its immunological efficacy evaluation at the mouse level.Using type 5 ade-novirus as a vector,a recombinant adenovirus expressing PRRSV GP3 protein was prepared and i-dentified in vitro by fluorescence observation,PCR,and Western blot analysis.Immunize mice with recombinant adenovirus and detect humoral and cellular immune responses induced by recombi-nant adenovirus using indirect ELISA and ELISpot methods.The recombinant adenovirus rAdGP3 was identified by enzyme digestion,PCR,fluorescence and Western blot,indicating that the recom-binant adenovirus rAdGP3 was successfully constructed and packaged.After immunizing mice,spe-cific antibodies and neutralizing antibodies were produced,indicating that the recombinant adenovi-rus could elicit strong humoral immunity.ELISpot and lymphocyte proliferation assays showed that the recombinant adenovirus vaccine could stimulate the secretion of IFN-γ-specific T lymphocytes and induce the proliferation of lymphocytes,indicating that the recombinant adenovi-rus could enhance the level of cellular immune response.In this study,rAdGP3 recombinant adeno-virus was successfully constructed and had good immunogenicity at the mouse level,which provid-ed a reference for the development of novel PRRSV vaccines.

This study constructed a porcine reproductive and respiratory syndrome virus(PRRSV)NADC30-like strain GP3 recombinant adenovirus vector vaccine through in vitro homologous re-combination to explore its immunological efficacy evaluation at the mouse level.Using type 5 ade-novirus as a vector,a recombinant adenovirus expressing PRRSV GP3 protein was prepared and i-dentified in vitro by fluorescence observation,PCR,and Western blot analysis.Immunize mice with recombinant adenovirus and detect humoral and cellular immune responses induced by recombi-nant adenovirus using indirect ELISA and ELISpot methods.The recombinant adenovirus rAdGP3 was identified by enzyme digestion,PCR,fluorescence and Western blot,indicating that the recom-binant adenovirus rAdGP3 was successfully constructed and packaged.After immunizing mice,spe-cific antibodies and neutralizing antibodies were produced,indicating that the recombinant adenovi-rus could elicit strong humoral immunity.ELISpot and lymphocyte proliferation assays showed that the recombinant adenovirus vaccine could stimulate the secretion of IFN-γ-specific T lymphocytes and induce the proliferation of lymphocytes,indicating that the recombinant adenovi-rus could enhance the level of cellular immune response.In this study,rAdGP3 recombinant adeno-virus was successfully constructed and had good immunogenicity at the mouse level,which provid-ed a reference for the development of novel PRRSV vaccines.

Porcine epidemic diarrhea (PED) is a highly contagious disease that causes high mortality in suckling piglets. Although several licensed inactivated and live attenuated vaccines were widely used, the infection rate remains high due to unsatisfactory protective efficacy. In this study, mRNA vaccine candidates against PED were prepared, and their immunogenicity was evaluated in mice and pregnant sows. The mRNA PED vaccine based on heterodimer of viral receptor binding region (RBD) showed good immunogenicity. It elicited robust humoral and cellular immune responses in mice, and the neutralizing antibody titer reached 1:300 after a single vaccination. Furthermore, it induced neutralizing antibody level similar to that of the inactivated vaccine in pregnant sows. This study developed a new design of PED vaccine based on the mRNA-RBD strategy and demonstrated the potential for clinical application.
Pregnancy ; Swine ; Animals ; Female ; Mice ; Antibodies, Viral ; Swine Diseases/epidemiology* ; Viral Vaccines/genetics* ; Antibodies, Neutralizing ; Vaccines, Attenuated ; Diarrhea/veterinary*

Objective: To investigate the expression pattern，underlying function and clinical significance of Guanylate-binding protein 1 ( GBP1) in pulmonary tuberculosis ( pTB) ． Methods: Immunohistochemical staining was applied to detect the expression of GBP1 in pTB specimensand control samples． Combined with Gene Expression Omnibus ( GEO) datasets ，including GSE83456 and GSE34608，receiver operating characteristic ( ROC) curve was depicted to assess the diagnostic value of GBP1 in pTB．Then，the correlation between GBP1 and related regulatory factors was analyzed by protein-protein interaction network ( PPI) ; Finally，the potential molecular mechanism of GBP1 in pTB was probed by Gene Set Enrichment Analysis( GSEA) . Results: Compared with the control group，GBP1 was significantly overexpressed in human pTB samples，including lung tissue and blood．The positive rate of GBP1 protein in pTB was 73. 9% . ROC curve analysis revealed that GBP1 might have important value in early diagnosis of pTB．GSEA analysis suggested that the hyper-expression of GBP1 was closely related to the host inflammatory response，IFN-γ/ α signaling pathway and TNF-α/ IL-6 signal transduction． Conclusion GBP1 is highly expressed in pTB tissues and is involved in the process of inflammatory response and host anti-tuberculosis infection ; GBP1 may be used as an early diagnostic marker or therapeutic target for pTB.

Background: Brucella infection induces brucellosis, a zoonotic disease. The intracellular circulation process and virulence of Brucella mainly depend on its type IV secretion system (T4SS) expressing secretory effectors. Secreted protein BspJ is a nucleomodulin of Brucella that invades the host cell nucleus. BspJ mediates host energy synthesis and apoptosis through interaction with proteins. However, the mechanism of BspJ as it affects the intracellular survival of Brucella remains to be clarified. Objectives: To verify the functions of nucleomodulin BspJ in Brucella's intracellular infection cycles. Methods: Constructed Brucella abortus BspJ gene deletion strain (B. abortus ΔBspJ) and complement strain (B. abortus pBspJ) and studied their roles in the proliferation of Brucella both in vivo and in vitro. Results: BspJ gene deletion reduced the survival and intracellular proliferation of Brucellaat the replicating Brucella-containing vacuoles (rBCV) stage. Compared with the parent strain, the colonization ability of the bacteria in mice was significantly reduced, causing less inflammatory infiltration and pathological damage. We also found that the knockout of BspJ altered the secretion of cytokines (interleukin [IL]-6, IL-1β, IL-10, tumor necrosis factor-α, interferon-γ) in host cells and in mice to affect the intracellular survival of Brucella. Conclusions BspJ is extremely important for the circulatory proliferation of Brucella in the host, and it may be involved in a previously unknown mechanism of Brucella's intracellular survival.

Background: There is an urgent need to find reliable and rapid bovine tuberculosis (bTB) diagnostics in response to the rising prevalence of bTB worldwide. Toll-like receptor 2 (TLR2) recognizes components of bTB and initiates antigen-presenting cells to mediate humoral immunity. Evaluating the affinity of antigens with TLR2 can form the basis of a new method for the diagnosis of bTB based on humoral immunity. Objectives: To develop a reliable and rapid strategy to improve diagnostic tools for bTB. Methods: In this study, we expressed and purified the sixteen bTB-specific recombinant proteins in Escherichia coli. The two antigenic proteins, MPT70 and MPT83, which were most valuable for serological diagnosis of bTB were screened. Molecular docking technology was used to analyze the affinity of MPT70, MPT83, dominant epitope peptide of MPT70 (M1), and dominant epitope peptide MPT83 (M2) with TLR2, combined with the detection results of enzyme-linked immunosorbent assay to evaluate the molecular docking effect. Results: The results showed that interaction surface Cα-atom root mean square deviation of proteins (M1, M2, MPT70, MPT83)-TLR2 protein are less than 2.5 A, showing a high affinity.It is verified by clinical serum samples that MPT70, MPT83, MPT70-MPT83 showed good diagnostic potential for the detection of anti-bTB IgG and M1, M2 can replace the whole protein as the detection antigen. Conclusions Molecular docking to evaluate the affinity of bTB protein and TLR2 combined with ELISA provides new insights for the diagnosis of bTB.

Background and Objectives: Sheep-induced pluripotent stem cells (siPSCs) have low reprogramming efficiency, thereby hampering their use in biotechnology and agriculture. Several studies have shown that some microRNAs play an important role in promoting somatic reprogramming in mouse and human. In this study, we investigated the effect of miR-200c-141 on somatic reprogramming in sheep and explored the mechanism of promoting the reprogramming. Methods: and Results: The lentivirus system driven by tetracycline (TET)-on carrying Oct4, Sox2, c-Myc, Klf4, Nanog, Lin28, hTERT, and SV40LT (OSKMNLST) could reprogram sheep kidney cells into pluripotent cells. Overexpression of miR-200c-141 in combination with OSKMNLST could significantly improve the efficiency of sheep iPSC generation (p＜0.01). Sheep iPSCs derived from miR-200c-141 showed embryonic stem cell (ESC)-like pluripotent properties, were positive for alkaline phosphatase and some pluripotent markers by quantitative real-time PCR (qRT-PCR) and immunofluorescence, and were able to differentiate into three germ layers in vitro. Oar-miR-200c was transfected into HEK293FT cells and was able to target the zinc finger E-box-binding homeobox 1 (ZEB1) 3’UTR using dual luciferase reporting analysis. Overexpression of oar-miR-200c in SKCs significantly reduced the expression of ZEB1, but increased the expression of E-cadherin by qRT-PCR and western blotting analysis. Conclusions These results suggest that miR-200c-141 can promote the reprogramming of sheep somatic cells to iPSCs, and oar-miR-200c targeted ZEB1 3’UTR, significantly decreased expression of ZEB1, and increased expression of E-cadherin. Oar-miR-200c may improve the MET process by affecting the TGF-β signaling pathway, thus improving the efficiency of somatic cell reprogramming in sheep.

A fluorescent microsphere-based immunochromatographic strip test (FICT) was developed for the rapid, sensitive, and quantitative detection of porcine reproductive and respiratory syndrome virus (PRRSV) antibodies at the pen-side. The assay was based on the formation of a sandwich immune-complex (anti-pig IgG-PRRSV antibodies-NSP7/N), which was validated by a comparison with IDEXX-ELISA using 3325 clinical specimens. The diagnostic specificity, sensitivity, and accuracy of FICT were 97.28, 93.41, and 94.95%, respectively. FICT showed a good correlation with the virus neutralization assay. Overall, a promising pen-side diagnostic tool was developed for the rapid and quantitative detection of PRRSV antibodies within 15 min.

Objective To prepare monoclonal antibodies (mAb) against the type Ⅳ secretion system protein VirB5 of Brucella melitensis and to provide a basis for pathgenic diagnosis and research of brucellosis.Methods Four SPF female BALB/c mice were subcutaneously immunized with purified VirB5 protein at a dose of 60 μg/mice,and immunization was strengthened every 2 weeks at a dose of 30 μg/mice,three times in total.Two weeks later,the orbital venous blood of mice was taken to determine the antibody titer,and then intraperitoneally injected for the fourth time to strengthen immunization.Three days later,mouse spleen cells were fused with mouse myeloma SP2/O cells in a ratio of 5:1.After 3 times of cell screening and monoclonal cloning,the hybridoma cell lines with stable secretion of VirB5 antibody were established;one BALB/c mouse was intraperitoneally injected with hybridoma cells,and ascites were collected and antibody was purified when the mouse abdomen was significantly enlarged.The immunological characteristics of mAbs were identified by indirect enzyme-linked immunosorbent assay (ELISA) and Western blotting.Results A total of 6 monoclonal cell lines (2-2,2-12,2-19,2-25,2-31 and 2-40) capable of secreting VirB5 antibody were established.Among them,the cell line 2-19 can stably secrete an antibody that specifically recognized the VirB5 protein,and the VirB5 antibody secreted by the cell line was identified as an IgG1 subtype,a kappa light chain,a mAb affinity constant of 1.6 × 108.The titer of ascites antibody of mouse intraperitoneally injected with hybridoma cell 2-19 was 1:51 200.Conclusion The high-affinity mAb of type Ⅳ secretion system protein VirB5 is successfully prepared,and the antibody can rapidly bind specifically to pathogens,providing an alternative material for establishment of brucellosis pathogen diagnostic method.

Iron is involved in the virulence and pathogenic effects of certain intracellular parasites.In the pathogenic process of Brucella,the uptaking and metabolism of host iron are closely related to intracellular parasitism and immunity escape of Brucella.In this paper,we elucidated the iron transport system,iron response regulators and nutrient immunity of iron based on the latest report and data about Brucella.