Objective To explore the humoral and cellular immune responses of a vaccine of S fragments from a new type reovirus R4 strain in mice.Methods Four recombinant plasmids were constructed by respectively cloning S 1, S2, S3,S4 genes into pcDNA3.1+, and mice were intramuscularly immunized with the recombinant plasmids in a dose of 100 μg/mouse.Control vector pcDNA3.1 +and phosphate buffered saline (PBS) were used as negative controls.The spe-cific antibody level and IgG subclass (IgG1, IgG2a, and IgG2b) were detected by ELISA, and cellular immune responses to R4 were assessed using an interferon ( IFN)-γELISpot assay .Results All recombinant plasmids induced significantly higher levels of anti-R4 IgG compared with that of the controls (pcDNA3.1 +and PBS), and the titers were highest in the mice immunized with S1 and S3.On the other hand, S1 gene induced highest IgG2a antibody and the cellular immune re-sponse was best .Conclusions After the mice immunized with S 1 gene recombinant plasmid , this plasmid can initiate both cellular and humoral immune responses in mice .S1 gene recombinant plasmid is a promising vaccine candidate .

Objective To isolate and identify the causative agent in an incident with crowd fever of adults in Henan province.Methods The cells was inoculated by the throat swabs of the patients and followed by neutralization assay and other molecular methods.Then indirect immunofluorescence assay was performed to detect the specific IgM/IgG antibodies against virus in the serum of the patients.Results We have isolated 2 strain adenoviruses from 10 swab samples,which were both identified as Ad11 by sequence analysis and neutralization test.6 of 10 samples were positive fer IgM specific for adenovirus and 3 positive for IgG.The remaining sample was negative for both.Conclusion The causative agent in this incident with crowd fever of adults was Ad11 in group B.

Objective To establish a chemiluminecentdetection method ( CLIA ) of HCV IgG antibody for the detection of HCV infection and therefore lay a foundation for the research and development of testing kit.Methods Based upon the indirect ELISA method, the microwell plate was coated with HCV-NS3 and HCV-Core antigen expressed through gene engineering, and the anti-human IgG antibody was labeled with horse radish peroxidase.In this way, the chemiluminesent detection method of HCV IgG antibody was established.Meanwhile, the serum specimen of randomly selected 198 patients infected with HCV from No.302 Hospital of PLA and 222 blood donors, and the results were compared.Results The HCV-IgG antibody, a positive consistent rate of 99.0%( 196/198 ) , a negative consistent rate of 98.2%(218/222), and a total consistent rate of 98.6%(414/420) were found through testing 420 serum specimen with self-made agent and contrast agent.One HCV positive serum was repetitively tested with the self-made agent for 10 times, and a coefficient of variation ( CV) of less than 10% was found.Conclusion The chemiluminescent detection method of HCV IgG antibody is initially established, and the method, with an outstanding specificity and sensitivity, is applicable for screening blood donors, clinically detecting HCV infection as well as epidemiological survey.

Objective To examine the expression profile of programmed death-ligand 1 (PD-L1) on lung endothelial or epithelial cells,and to determine the specific role of PD-L1 in mouse model of indirect acute lung injury (i-ALI).Methods Eighty male C57BL/6 mice were randomly divided into two parts (both n =40).The effects of different administration routes on the expression of PD-L1 were observed.The mice in each part were randomly divided into sham,i-ALI,i-ALI+small interfering RNA (siRNA) random sequence control,and i-ALI+PD-L1 siRNA which could specifically inhibit PD-L1 expression groups,with l0 mice in each group.i-ALI was reproduced in a mouse model of hemorrhagic shock in combination with a subsequent cecal ligation and puncture (CLP).In sham group,only bilateral femoral arteries were ligated without catheterization or bleeding,and only cecum was separated but perforation was not ligated.Intravenous or intratracheal delivery of PD-L1 siRNA was performed 2 hours following the resuscitation to suppress the expression of PD-L1 on lung endothelial or epithelial cells.The mice in i-ALI+siRNA random sequence control group were given siRNA random sequence without inhibition effect on PD-L1 expression,and those in sham group and i-ALI group were given 100 μL phosphate buffered saline (PBS).The mice were sacrificed at 24 hours after CLP,and samples of blood,lung tissue and bronchoalveolar lavage fluid (BALF) were harvested.Expressions of PD-L1 were determined with flow cytometry.Cytokines and chemokines in plasma,lung tissue and BALF were determined by enzyme linked immunosorbent assay (ELISA).The protein concentration in plasma and BALF and the activity of myeloperoxidase (MPO) in lung tissue were quantitatively measured.The pathological changes in lung tissue were observed under light microscope.Results ① Compared with sham group,PD-L1 expression on lung endothelial or epithelial cells were significantly elevated in i-ALI group [endothelial cells:(27.88 ± 1.53)％ vs.(19.64 ± 1.03)％,epithelial cells:(58.70 ± 8.21)％ vs.(29.23 ± 3.94)％,both P ＜ 0.05].② Mice received intravenous delivery of liposomal-encapsulated siRNA had significantly lower expression of PD-L1 on lung endothelial cells as compared with that of i-ALI group [(21.37 ± 0.76)％ vs.(27.88 ± 1.53)％,P ＜ 0.05].Intratracheal delivery of naked PD-L1 siRNA mainly inhibited the PD-L1 expression on epithelial cell as compared with that of i-ALI group [(31.23±4.71) ％ vs.(58.70±8.21) ％,P ＜ 0.05].The expression of PD-L1 in pulmonary microvascular endothelial cells or pulmonary epithelial cells of i-ALI mice was not affected by siRNA random sequence.③ PD-L1 silencing on pulmonary endothelial cells induced by intravenous delivery of PD-L1 siRNA led to a lower protein ratio of BALF/plasma [(4.48 ± 0.35) × 10-3 vs.(6.11 ± 0.56) × 10-3,P ＜ 0.05] and a decreased MPO activity in lung tissue (U · μg-1 · min-1:2.48 ± 0.47 vs.4.56 ± 0.52,P ＜ 0.05) as compared with that of i-ALI group.Moreover,inflammatory mediator levels such as interleukin-6 (IL-6),monocyte chemoattractant protein-1 (MCP-1),macrophage inflammatory protein-2 (MIP-2) and tumor necrosis factor-α (TNF-α) in lung tissue or plasma were significantly reduced following PD-L1 suppression on endothelial cells as compared with those of i-ALI group [IL-6 (ng/g):177.4±23.2 vs.287.9±57.3,MCP-1 (ng/g):839.6±91.7 vs.1 395.7±211.9,MIP-2 (ng/g):923.7± 107.3 vs.1 700.9±240.2 in lung tissue;IL-6 (ng/L):950.2±192.7 vs.1 828.2±243.6,TNF-α (ng/L):258.7±29.1 vs.443.0 ± 58.1,MCP-1 (ng/L):2 583.8±302.3 vs.4 328.1 ±416.4,MIP-2 (ng/L):1 512.9± 165.6 vs.2 005.9 ± 85.7 in plasma,all P ＜ 0.05],however,there was no significant change in the levels of inflammatory factors in BALF.It was shown in lung tissue histology that PD-L1 silencing on pulmonary endothelial cells induced by intravenous delivery of PD-L1 siRNA led to lessened pulmonary edema and reduced immune cells emigration.Intratracheal delivery of PD-L1 siRNA for PD-L1 suppression on epithelial cells had minimal effects on protein ratio of BALF/plasma,MPO activity,inflammatory mediator expressions in lung tissue,plasma,and BALF as well as lung tissue histology.Conclusion PD-L1 silencing on endothelial cells but not epithelial cells protected mice against hemorrhagic shock-sepsis induced i-ALI.