Objective To prepare the recombinant Echinococcus granulosus Polo-like kinase 2 (rEgPLK2) protein and evaluate its immunoprotective efficacy against cystic echinococcosis, so as to provide insights into research and development of novel vaccines against echinococcosis. Methods The Polo-like kinase (PLK) protein sequences were retrieved from 12 species in the NCBI protein database, including E. granulosus and E. multilocularis. Multiple sequence alignment was performed using the Clustal Omega program, and structural visualization and homology analysis were conducted using the ESPript 3.2 program. The recombinant plasmid pET-30a-EgPLK2 was transformed into BL21(DE3) competent cells. Protein expression was induced with isopropyl-β-D-thiogalactoside (IPTG), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was performed to characterize the expression and molecular weight of the rEgPLK2 protein. The purified rEgPLK2 protein was thoroughly emulsified with Freund’s complete adjuvant at a 1 : 1 volume ratio. Two New Zealand white rabbits were immunized with multipoint subcutaneous injection on the back at a dose of 300 μg per rabbit for primary immunization. For booster immunizations, the protein was emulsified with Freund’s incomplete adjuvant at a 1 : 1 volume ratio and administered on days 14, 28, and 42 after the primary immunization at a dose of 150 μg per rabbit. Serum was sampled from the rabbit ear vein on day 7 after the final immunization to yield anti-rEgPLK2 polyclonal antibodies. Antibody titer was determined by indirect enzyme-linked immunosorbent assay (ELISA), and antibody specificity was verified by Western blotting. The tissue localization of the EgPLK2 protein was detected in E. granulosus protoscoleces and adult worms using immunofluorescence assay (IFA). Eighteen 6- to 8-week-old female SPF-grade BALB/c mice were randomly divided into three groups, including the blank control group, rEgPLK2-ISA immunization group, and PBS-ISA adjuvant control group, of 6 mice each group. Mice in the rEgPLK2-ISA immunization group and PBSISA group received three primary immunizations via intramuscular injection, and animals in the rEgPLK2-ISA immunization group was inoculated with immunogens prepared by emulsifying rEgPLK2 protein with ISA 201 adjuvant at a 1 : 1 volume ratio (6 μg per mouse), while mice in the PBS-ISA adjuvant control group received an equal volume of PBS emulsified with ISA adjuvant at a 1 : 1 volume ratio. A fourth booster immunization was administered via intraperitoneal injection. Mice in the rEgPLK2-ISA immunization group received a booster immunization with 8 μg of rEgPLK2 protein per mouse, and animals in the PBS-ISA group received an equal volume of PBS, with immunizations given at 2-week intervals. Mice in the blank control group were given no treatment, and housed under standard conditions. Tail vein blood was collected from all mice 7 days after the final immunization, and levels of specific anti-rEgPLK2 IgG antibody and its subclasses (IgG1, IgG2a, IgG2b, IgG3) were measured by indirect ELISA. E. granulosus infection was modelled in mice through injection with 1 000 E. granulosus protoscoleces via intrahepatic portal vein in the rEgPLK2-ISA immunization group and PBS-ISA adjuvant control group 2 weeks after the last immunization. All mice were sacrificed and dissected. The number of cysts was counted in mouse livers, and the cyst reduction rate was calculated. Liver tissues were processed for paraffin sectioning and stained with hematoxylin and eosin (HE), and histopathological changes were examined under a light microscope. Results Sequence analysis revealed that EgPLK2 shared a high amino acid sequence homology with E. multilocularis PLK2 (EmPLK2) and contained the typical domains of the Polo-like kinase family, including the serine/threonine protein kinase catalytic domain (STKc) and Polo-box. The IPTG-induced rEgPLK2 protein was mainly expressed in the form of inclusion bodies, and the purified rEgPLK2 protein showed a relative molecular mass of approximately 70 kDa. The prepared rabbit anti-rEgPLK2 polyclonal antibody had a titer of 1 : 256 000, and Western blotting assay showed that this anti-body specifically recognized the rEgPLK2 protein with a relative molecular mass of approximately 70 kDa. Immunofluorescence assay showed that the EgPLK2 protein was localized in the excretory bladder and rostellum of E. granulosus protoscoleces, as well as the tegument, suckers, and inter-proglottid junctions of adult worms. Immunoprotective assay showed that the serum levels of specific anti-rEgPLK2 IgG, IgG1, IgG2a, and IgG2b antibodies were 2.92 ± 0.49, 0.33 ± 0.10, 0.31 (0.36), and 3.12 (1.73) in mice in the rEgPLK2-ISA immunization group, which were all significantly higher than those in the PBS-ISA adjuvant control group (0.14 ± 0.04, 0.07 ± 0.01, 0.12 ± 0.04, and 0.11 ± 0.04, respectively) (t = 19.28 and 8.46, Z = 3.75 and 4.15; all P values < 0.001); however, there was no significant difference in the serum anti-IgG3 antibody level between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group [0.07 (0.01) vs. 0.073 (0.07); Z = 0.69, P > 0.05)]. In the mouse model of E. granulosus infections, the area of hepatic lesions was reduced and the inflammatory infiltration was alleviated in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and the number of hepatic cysts was higher in the PBS-ISA adjuvant control group than in the rEgPLK2-ISA immunization group [8.00 (2.00) vs. 1.00 (0.75); Z = −2.93, P < 0.01], with a cyst reduction rate of 80.40%. Indirect ELISA assay measured higher serum levels of specific anti-rEgPLK2 IgG (3.28 ± 0.48 vs. 0.11 ± 0.04; t = 15.86, P < 0.01), IgG1 (0.29 ± 0.02 vs. 0.09 ± 0.01; t = 15.67, P < 0.01), IgG2a [3.71 (1.09) vs. 0.08 (0.03); Z = 2.88, P < 0.01], and IgG2b antibodies [3.34 (1.01) vs. 0.08 (0.03); Z = 2.88, P < 0.01] in the rEgPLK2-ISA immunization group than in the PBS-ISA adjuvant control group, and there was no significant difference in the serum level of the specific anti-rEgPLK2 IgG3 antibody between the rEgPLK2-ISA immunization group and the PBS-ISA adjuvant control group (0.07 ± 0.01 vs. 0.07 ± 0.01; t = 1.29, P > 0.05). Conclusions The prokaryotic expression system has been successfully constructed for the EgPLK2 gene and the anti-rEgPLK2 polyclonal antibody has been obtained. The rEgPLK2 protein exhibits a high immunogenicity, and is effective to protect against E. granulosus infection, and inhibits cyst development, which is a promising candidate vaccine target against cystic echinococcosis.

Objective To detect the positive rates of antibodies against avian influenza virus (AIV) subtypes H5, H6, H7 and H9 among people in poultry occupations in Guangdong province and to analyze the transmission of various subtypes of AIV from poultry to human contacts for the prevention and control of novel AIV infection in human beings.Methods Serum specimens were collected from 1066 peo-ple in poultry occupations ( occupational group) and 205 people not in poultry occupations ( non-occupational group) in 10 cities of Guangdong province.The inactivated AIV strains, isolated from poultry or environment of Guangdong province, were used as antigens to detect antibodies against AIV subtypes H5, H6, H7 and H9 by using the hemagglutination inhibition ( HI) assay.Results The positive rates of antibodies against AIV subtypes H5, H6, H7 and H9 carried by people from the occupational group were respectively 0.44%, 0%, 0.30%and 0.30%in 2013 and 1.08%, 0.0%, 0.0%and 0.27%in 2014.Only the anti-H9 anti-bodies were detected in serum samples collected form people in the non-occupational group in 2013 with a positive rate of 0.95%.No significant differences with the positive rates of anti-AIV antibodies were found between the occupational group and the non-occupational group.However, the geometric mean titer ( GMT) of anti-AVI antibodies in people from the occupational group was higher than that of the non-occupational group.Conclusion Although a grand spread of AIV from avian to human is not likely to happen yet, con-tacting with poultry is the risk factor for AIV infection in Guangdong population.A long-term surveillance of anti-AIV antibodies in serum should be strengthened among people in poultry occupations for the timely pre-vention and control of novel AIV outbreak.

Ribavirin is a broad-spectrum antiviral agent and glycyrrhizin has activities of anti-inflammation, immunoregulation and anti-viral infections. To enhance antiviral efficacy and weaken side-effects of ribavirin, antiviral effects of the combination of glycyrrhizin and ribavirin were studied in the present study. Firstly, a mouse model of viral pneumonia was established by inoculation of influenza H1N1 virus. Protective effects of glycyrrhizin and ribavirin used alone or in combination against H1N1 virus infection in mice were evaluated based on the survival rate, lung index and virus titer in lungs of mice. Results showed that the combination of glycyrrhizin and ribavirin significantly inhibited the lung consolidation with a 36% inhibition ratio on the lung swell of infected mice. The combination of the two drugs exhibited synergetic effects on survival of infected mice. The combination of 50 mg · kg(-1) · d(-1) glycyrrhizin and 40 mg · kg(-1) · d(-1) ribavirin resulted a 100% protection for infected mice with a synergetic value of 36, which was significantly higher than the control group and each drug alone. This combination also resulted a significant drop of lung virus titer (P < 0.01), as well as inhibition on the production of proinflammatory cytokines IL-6 (P < 0.01), TNF-α (P < 0.01) and IL-1β (P < 0.05) induced by virus infection compared to the control. The treatment of ribavirin plus glycyrrhizin was more effective in influenza A infection in mice than either compound used alone, which suggested a potential clinical value of the combination of the two agents.

Objective To investigate the prevalence rate of ovine hepatic cystic echinococcosis (HCE) in sheep in Quaker Wusu area of Bayinbuluke of Xinjiang by ultrasonography and provide evidence for the prevention and control of HCE in sheep.Methods The prevalence screening of HCE in sheep was conducted based on ultrasound images in this area in July 2014.The sheep were divided into different groups by dental age to calculate the age specific prevalence rate of HCE and analyzed the correlation between the dental age and the prevalence rate.Results The total prevalence rate of HCE in sheep in this area was 36.9％.The prevalence rates of none-calcified HCE and calcified HCE were 7.3％ and 29.6％,respectively.The prevalence rates of none-calcified HCE in different age groups were 1.2％ (1-2 years old),1.4％ (2-3 years old),14.0％ (3-4 years old),10.0％ (4-5 years old),15.6％(5-6 years old) and 4.2％(＞6 years old) respectively.The prevalence rate of calcified HCE in different age groups were 9.9％(1-2 years old),16.2％ (2-3 years old),31.6％(3-4 years old),47.8％(4-5 years old),42.2％(5-6 years old) and 41.7％(＞6 years old) respectively.The prevalence rate of HCE in 1-2 years old group was lower than those in other groups,the prevalence rate of HCE in age groups ＞3 years increased significantly.There was positive correlation between the prevalence rate of HCE and dental age (r=0.372,R2=0.107,F=44.176,P=0.000).Conclusion HCE is highly endemic in Quaker Wusu area.The prevalence rate of HCE is low in sheep with young age and high in sheep aged 3-4 years.It is necessary to conduct early prevention of HCE in sheep in this area.

Animals ; Asian Continental Ancestry Group ; Chickens ; China ; epidemiology ; Cytokines ; metabolism ; Genetic Variation ; Genotype ; Humans ; Influenza A Virus, H7N9 Subtype ; classification ; genetics ; pathogenicity ; Influenza A Virus, H9N2 Subtype ; genetics ; Influenza in Birds ; transmission ; virology ; Influenza, Human ; ethnology ; transmission ; virology ; Mice, Inbred BALB C ; Molecular Sequence Data ; Orthomyxoviridae Infections ; metabolism ; mortality ; virology ; Phylogeny ; Seasons ; Survival Rate ; Virulence ; genetics

After sequencing, we amplified and cloned foot-and-mouth disease virus (FMDV) O/QYYS/s/06 whole genome by three fragments. These three fragments were cloned into vector P43 one by one to construct recombinant plasmid P43C, which carried the full-length cDNA of FMDV O/QYYS/s/06. Then, plasmid P43C and plasmid T7 expressing T7 RNA polymerase were co-transfected into BHK-21 cells. After 48 h, we harvested the culture broth from transfected BHK-21 cells and inoculated into 2-3 day-old sucking mice. After four generation passage, the virus harvested from sucking mice was confirmed to be type O FMDV by the indirect hemagglutination test, sucking mice's neutralization test and sequencing. The results showed that we have successfully constructed the full-length cDNA clone of FMDV O/QYYS/s/06 strain.
Animals ; Animals, Newborn ; Cloning, Molecular ; DNA, Complementary ; genetics ; DNA, Viral ; biosynthesis ; genetics ; Foot-and-Mouth Disease ; virology ; Foot-and-Mouth Disease Virus ; classification ; genetics ; pathogenicity ; Mice ; Transcription, Genetic ; Transfection

OBJECTIVETo explore the effect of recombinant human soluble CD(40) ligand (rhsCD(40)L) and CD(40)L cDNA transfected cell (CD(40)L-TC) on the behavior of malignant B lymphocytes, and investigate the possibility of using rhsCD(40)L as a new bio-factor in tumor immunotherapy.

METHODrhsCD(40)L and CD(40)L-TC were obtained by gene recombinant techniques. Multiple myeloma cell lines, XG2, XG7, U266 and 8226, B-lymphoma cell lines, Raji and Daudi were selected to detect responses to rhsCD(40)L and CD(40)L-TC stimulation. Cell growth curve, cell cycle, early apoptosis as well as membrane surface molecules on these cell lines were analyzed.

RESULTS(1) The expression levels of CD(40) molecule on malignant B lymphocytes showed heterogeneity. High level of CD(40) on XG2, moderate on 8266, Raji, and Daudi, and no expression on U266 and XG7 were detected. The rhsCD(40)L stimulation gave rise to a typical homo-type cell aggregation of XG2 and Daudi. Meanwhile, at least 10 to 20 of CD(40)(+) XG2 or CD(40)(+) Daudi cells were found adherent to one pre-treat ed CD(40)L-TC. (2) Co-incubation with rhsCD(40)L (5 micro g/ml), or CD(40)L-TC (tumor cell: CD(40) = 5:1) resulted in a significant inhibition of in vitro cell growth of XG2, Raji and Daudi, with G(1)-phase arrest for XG2 and G(2)-phase for Raji and Daudi. These two kinds of CD(40) stimulators induced XG2, Raji and Daudi cells to apoptosis in vitro. The apoptotic rate for XG2 was 23.3% (rhsCD(40)L) and 18.8% (CD(40)L-TC), for Daudi 14.2% and 15.9%, and for Raji 11.6% and 8.9% respectively. (3) Phenotype analysis showed that CD(95) expression levels were significantly up-regulated on XG2, Raji and Daudi after stimulation with rhsCD(40)L or CD(40)L-TC, and CD(80) and CD(18) expression levels on Raji were respectively enhanced and decreased.

CONCLUSIONThe abilities to directly inhibit XG2, Daudi and Raji cell proliferation, to induce themapoptosis, as well as to up-regulate immune co-stimulator molecule CD(80) expression on Raji cells would make rhsCD(40)L a potential bio-factor for tumor immuno-therapy.

B-Lymphocytes ; drug effects ; metabolism ; pathology ; CD40 Antigens ; metabolism ; CD40 Ligand ; genetics ; metabolism ; pharmacology ; Cell Division ; drug effects ; Coculture Techniques ; DNA, Complementary ; genetics ; Humans ; Lymphoma, B-Cell ; metabolism ; pathology ; Recombinant Proteins ; pharmacology ; Time Factors ; Transfection ; Tumor Cells, Cultured ; drug effects