This study aims to prepare monoclonal antibody to S1 protein of porcine epidemic diar-rhea virus(PEDV).E.coli expression system and affinity chromatography were used to success-fully obtain purified recombinant PEDV S1 protein.After immunizing BALB/c mice,hybridoma technology and indirect ELISA were used to prepare and screen positive hybridoma cells.Finally,ascites antibodies were prepared by in vivo induction method.ELISA results showed that a total of 4 hybridoma cell lines with anti-PEDV S1 monoclonal antibody were screened,and they were named E6,G3,H6 and F2.The supernatant titers of all 4 hybridoma cell lines reached 1∶6 400.The monoclonal antibody H6 with higher antibody titers and more stable antibody secretion was selected for antibody type identification.It was found that monoclonal antibody H6 belongs to the IgG1 subclass and the light chain is the λ chain.The antibody titers that induced mouse ascites were 1∶106 and without cross-reaction with other proteins.Western blot results showed that the monoclonal antibody exhibited specific bands at 38 kDa with the recombinant S1 protein,PEDV QY2016,and PEDV CV777 strains.The IFA results also showed that the monoclonal antibody reacted with cells infected with PEDV QY2016 and PEDV CV777 strains,exhibiting a green fluo-rescent signal.The affinity constant of monoclonal antibody H6 was K=1.75×107 moL/L,indica-ting that the H6 strain had a good affinity and could be used for the development of subsequent di-agnostic antibodies.In summary,this study successfully prepared monoclonal antibodies that can specifically recognize PEDV S1 protein,which can be used for the antigen detection of PEDV and providing important test materials for the research of PEDV detection methods.

This study aims to prepare monoclonal antibody to S1 protein of porcine epidemic diar-rhea virus(PEDV).E.coli expression system and affinity chromatography were used to success-fully obtain purified recombinant PEDV S1 protein.After immunizing BALB/c mice,hybridoma technology and indirect ELISA were used to prepare and screen positive hybridoma cells.Finally,ascites antibodies were prepared by in vivo induction method.ELISA results showed that a total of 4 hybridoma cell lines with anti-PEDV S1 monoclonal antibody were screened,and they were named E6,G3,H6 and F2.The supernatant titers of all 4 hybridoma cell lines reached 1∶6 400.The monoclonal antibody H6 with higher antibody titers and more stable antibody secretion was selected for antibody type identification.It was found that monoclonal antibody H6 belongs to the IgG1 subclass and the light chain is the λ chain.The antibody titers that induced mouse ascites were 1∶106 and without cross-reaction with other proteins.Western blot results showed that the monoclonal antibody exhibited specific bands at 38 kDa with the recombinant S1 protein,PEDV QY2016,and PEDV CV777 strains.The IFA results also showed that the monoclonal antibody reacted with cells infected with PEDV QY2016 and PEDV CV777 strains,exhibiting a green fluo-rescent signal.The affinity constant of monoclonal antibody H6 was K=1.75×107 moL/L,indica-ting that the H6 strain had a good affinity and could be used for the development of subsequent di-agnostic antibodies.In summary,this study successfully prepared monoclonal antibodies that can specifically recognize PEDV S1 protein,which can be used for the antigen detection of PEDV and providing important test materials for the research of PEDV detection methods.

Porcine circovirus type 2(PCV2)mainly damages the immune cells of pigs,causing lym-phocyte depletion and immune suppression.Interleukin(IL)-15 regulates immune functions wide-ly,and plays an important regulatory role in the survival,proliferation,differentiation and immune function of a variety of immune cells such as natural killer(NK),CD8+T cells and NKT cells.In this study,in order to determine the effect of PCV2 on IL-15 expression,4-week-old piglets(n=4)were infected with PCV2 and the negative control group(n=4)was set up.On day 7 post-infec-tion,the inguinal lymph nodes of the infected and control groups were collected,and porcine cyto-kine antibody microarray(QAP-CYT-1)was employed to quantify the expression of cytokines in the tissues,screen for differential cytokines,and GO and KEGG enrichment analysis for IL-15 were conducted.Real-time quantitative fluorescent PCR(qPCR)and ELISA were used to verify the level of IL-15 mRNA and protein,and those in porcine peripheral blood mononuclear cells(PBMC)and serum were simultaneously detected.Compared with the negative control group,the expression lev-el of IL-15 was significantly reduced in the infected group(P＜0.05);IL-15 was mainly involved in cytokine-cytokine receptor interactions,immune responses,cellular activation,and the regulation of JAK-STAT and TNF signaling pathways.The levels of IL-15 mRNA and protein in inguinal lymph nodes in the infected group were significantly lower than those in the control group(P＜0.05),which was consistent with the detection results of QAP-CYT-1.However,there was no significant difference in IL-15 mRNA and protein levels in PBMC and serum.These results indicate that PCV2 can inhibit IL-15 in the inguinal lymph node microenvironment of piglets.This study can provide important information for further revealing the immunosuppressive mechanism of PCV2.

Background: Enteritis is one of the most frequently reported symptoms in piglets infected with porcine circovirus type 2 (PCV2), but the immunopathogenesis has not been reported. Objectives: This study examined the effect of a PCV2 infection on the intestinal mucosal immune function through morphological observations and immune-related molecular detection. Methods: Morphological changes within the ileum of piglets during a PCV2 infection were observed. The expression of the related-molecules was analyzed using a gene chip. The immunocyte subsets were analyzed by flow cytometry. The secretory immunoglobulin A (SIgA) content was analyzed by enzyme-linked immunosorbent assay. Results: The PCV2 infection caused ileal villus damage, intestinal epithelial cells exfoliation, and an increase in lymphocytes in the lamina propria at 21 days post-infection.Differentially expressed genes occurred in the defense response, inflammatory response, and the complement and coagulation cascade reactions. Most of them were downregulated significantly at the induction site and upregulated at the effector site. The genes associated with SIgA production were downregulated significantly at the induction site. In contrast, the expression of the Toll-like receptor-related genes was upregulated significantly at the effector site. The frequencies of dendritic cells, B cells, and CD8 + T cells were upregulated at the 2 sites. The SIgA content decreased significantly in the ileal mucosa. Conclusions PCV2 infections can cause damage to the ileum that is associated with changes in immune-related gene expression, immune-related cell subsets, and SIgA production.These findings elucidated the molecular changes in the ileum after a PCV2 infection from the perspective of intestinal mucosal immunity, which provides insights into a further study for PCV2-induced enteritis.

In order to survey the prevalence of encephalomyocarditis virus (EMCV) infection in pigs in Hebei Province from 2006 to 2008,a total of 1306 swine serum from 31 farms in 10 regions in Hebei were tested for antibodies against EMCV nonstructural protein 2C by ELISA.Positive rates of antibodies in different regions and different age groups were analyzed.The results showed that antibodies against EMCV 2C were found in 176 out of 1306 serum samples collected from Hebei Province and the total positive rate was 13.48%.Seroprevalence of EMCV infection appeared in six out of ten surveyed regions and the highest positive rate was 26%.There was significant difference of seroprevalence in EMCV infection between breeder sows and other swine species.This survey indicated that EMCV infection has occurred in pig farms in most regions of Hebei Province and EMCV-carried breeder sows were one of the crucial causes for EMCV infection and prevalence.

BACKGROUND:Many studies have demonstrated that restoration of femoral offset in revision total hip arthroplasty would contribute to the recovery of joint function.OBJECTIVE:To investigate the importance of restoration of femoral offset in revision total hip arthreplasty on the recovery of joint function.METHODS:An observational study was performed at the Department of Orthopedics,Third Affiliated Hospital of Guangzhou Medical University between February 2004 and May 2007.A total of 15 patients with the revision total hip arthroplasty,including 12 males and 3 females,aging 62 75 years,averaging 67 years old,were recruited into this study.Harris evaluation system was used to evaluate joint function.The femoral neck anteversion and the femoral offset were measured by the method of Sakai.The vertical distance from the teardrop line to the most prominent point of the lesser trochanter was measured from each radiograph.References were combined to investigate the effect of restoration of femoral offset in revision total hip arthroplasty on joint function.RESULTS AND CONCLUSION:All the 15 patients were recruited into this study.The duration of follow-up ranged from 24 months to 5 years.We measured the femoral offset on pre- and post-operative radiographs,and the results indicated that the femoral offset of 4 patients were above 4 mm.The femoral offset of 11 patients was restored.The femoral offset were 22-48 (32.21±0.64) mm pre- and 22-57 (36.13±0.82) mm post-operative radiographs,respectively.The mean difference in femoral offset post-operatively was significant (t=0.424,P=0.01 ).Harris scores were good in 4 cases,passable in 2 cases,and poor in 9 cases pre-operatively,and the scores were excellent in 8 cases,good in 4 cases,passable in 2 cases,and poor in 1 case post-operatively.The score of Harris evaluation system in the patient of restoration group and failed restoration group were 88.72±5.3 (80%) and 72.32±6.5 (27%) post-operative at 1 month respectively.The mean difference of the score was significant (χ~2=1.245,P<0.05).The 3 patients had complication,one was the dislocation of hip,and two had the pain of hip.All the patients with complication were in failed restoration of femoral offset,which was above 4 mm.The restoration of femoral offset contributes to the recovery of joint function and reduce complication occurrence after total hip arthroplasty revision.