Human rotavirus (RV) is one of the main pathogens that cause non-bacterial acute gastroenteritis diseases globally. Live attenuated vaccine is an effective method to prevent RV infection. In order to improve the safety of RV vaccines, it is a good choice to develop other forms of vaccines other than live virus vaccines to avoid attenuated vaccine strains to restore virulence through back mutation or cause environmental contamination. This article reviews the research of RV virus like particle(VLP) vaccines.

The challenges posed by norovirus infections to global health are increasing accompa-nied by the rapid rate of the genetic and antigenic evolution of circulating noroviruses. Due to lack of in vitro culture cells and small animal models, norovirus vaccine cannot be prepared by using traditional techniques. With the in-depth understanding and study of norovirus, the subunit vaccines against norovirus infection based on P particles have been developed and presented the characteristics of easily expressed, low cost, high immunogenicity, stable structure and so on. In addition, norovirus P particle has been used as a subvi-ral nanoparticle for vaccine development against other viruses and for antibody production against chronic dis-ease ( Alzheimer′s disease) , which benefits from the accommodation of foreign antigens in the three loops of P particle. In this review, we describe the progresses in the field of P particle related vaccines for providing suggestions about the research and development of multivalent vaccines in China.

Objective To find out more about the population structure and clonal complex of clinical Vibrio parahaemolyticus strains in Asia.Methods Clinical Vibrio parahaemolyticus strains data were screened in Asia with complete ST and pST types from PubMLST public database,their subgroup and complex were analyzed,and the minimum spanning tree based on ST and pST types respectively was completed.Results From the database,341 items of ST and pST types of Asian clinical Vibrio parahaemolyticus strains were screened,including 157 ST,most of which were of ST3 type.Totally 214 items of data came from China (including Hong Kong and Taiwan),and covered 133 ST,most of which were of ST3 type.eBURST software was used and 17 groups and 94 singletons were found.Software STRUCTURE analysis showed that the appropriate subset number of clinical V.parahaemolyticus strains in Asia was 7,and that the average distance between samples in each subgroup was 0.9113.Conclusion Clinical V.parahaemolyticus strains in Asia show high diversity and can be subdivided into seven subgroups.ST3 type is dominating when multilocus sequence typing(MLST)is used and pST2 type is the majority by AA-MLST typing.

Objective To learn more about virulence genes and clonal complex group structure of Vibrio parahaemolyticus (VPH)strains separated from aquatic products in East China coastal areas between 2007 and 2012.Methods Seventy-nine strains separated from aquatic products in eastern coastal areas(Guandong,Fujian,Shanghai,Shandong,Jiangsu and Beijing)of China between 2007 and 2012 were identified as VPH by real-time-PCR with gene tlh.Gene tdh,trh and orf8 were also detected.Subgroup analysis and complex analysis were conducted of the VPH strains to build the minimum spanning tree respectively based on ST and pST types.Results In 79 VPH strains,gene tlh was positive while 8.86%(7 /79)of the isolates of gene tdh were positive.The carrying rate of gene orf8 was 8.86%.These 79 strains were of 69 ST types,involving 3 clonal complex and 62 singleton.By amino acid(AA)-multilocus sequence typing(MLST),79 strains covered the 23 pST types,2 clonal complexes and 1 singleton.The 363 single nucleotide polymorphisms(SNPs)were divided into 68 patterns.Conclusion VPH strains from aquatic products in eastern coastal areas of China are characterized by high polymorphisms and a low carrying rate of virulence genes.ST3 type is dominating when MLST typing is used while pST1 type is the majority by AA-MLST typing.

Background Pentacam anterior segment analysis system (Pentacam) is more accurate in the quantitative evaluation of ocular anterior segment in primary angle-closure glaucoma (PACG) eyes than slit lamp microscope and ultrasound biomicroscope (UBM).However,its accuracy in the earlier stage of PACG before and after YAG laser peripheral iridotomy (LPI) is not fully elucidated.Objective This study was to assess the effect of YAG LPI in PACG patients with Pentacam.Methods A prospective self-controlled study was performed.Thirtyfive fellow eyes (pre-clinical stage of PACG) of acute PACG and 35 fellow eyes of chronic PACG were included in the Second Hospital of Hebei Medical University from July,2012 to December,2013.YAG LPI was performed on the eyes,and the parameters of ocular anterior segment including central anterior chamber depth (ACD),anterior chamber volume (ACV) and peripheral anterior chamber angle (ACA) were measured and compared by Pentacam before and 1 day,7 days,28 days after operation.This study was approved by the Ethic Committee of the Second Hospital of Hebei Medical University and informed consent was obtained from all subjects.Results In pre-clinical stage of PACG eyes,the postoperative ACD and ACV values were increased in comparison with preoperation,showing significant differences among various time points (ACD:F =6.783,P =0.004;ACV:F =19.090,P =0.000),and no significant difference was found in ACA among different time points (F =0.153,P =0.928).In the fellow eyes of chronic PACG,the postoperative ACD and ACV values were larger than those of preoperation,with significant differences among various time points (ACD:F =21.576,P =0.000;ACV:F =47.506,P =0.000),and no significant difference was found in ACA among different time points (F=0.581,P=0.629).The change values of ACD and ACV were (0.064±0.022) mm and (27.840±4.963) mm3 in the eyes of pre-clinical stage of PACG,and those in the fellow eyes of chronic PACG were (0.047-± 0.020) mm and (21.000 ± 3.278) mm3,showing significant differences between the two groups (ACD:t=2.783,P=0.008;ACV:t=5.749,P=0.000).Conclusions Pentacam allows easy,fast,automatic and non-contact quantification and three-dimension image of the anterior chamber parameters before and after YAG LPI in pre-clinical stage of PACG eyes and fellow eyes of chronic PACG.The ACD deepens and ACV increases after LPI in glaucomous eyes,especially in the pre-clinical stage of PACG eyes.

Objective To compare the relationship between the enzyme‐linked immunosorbent assay(ELISA) reagent and West‐ern blot(WB) confirmation reagent for analyzing the quality lever of human T‐cell lymphotropic virus(HTLV) detection reagent . Methods The WB confirmation reagent was used to detect anti‐HTLV antibody in 156 human serum samples of ELISA prelimina‐ry screening positive .The ELISA cut‐off value(optimal value) was selected by using the two‐graph receiver operating characteristics (TG‐ROC) analytical method .The two‐by‐two table analysis was constructed to analyze the consistency of results detected by the two methods ,moreover the McNemar test was used to evaluate the consistency of detection results .The quality level of HTLV de‐tection reagent was comprehensively evaluated .Results Among 156 serum samples of ELISA preliminary screening positive ,only 40 samples were positive by the WB confirmation ,and other 116 samples were negative .The sensitivity and specificity of ELISA de‐tection reagent obtained by TG‐ROC analysis were 97 .5% and 45 .7% respectively ,the TG‐ROC test also indicated that the detec‐tion results had significant difference between ELISA and WB(P<0 .05) .By adjusting the cut‐off value ,the sensitivity and specific‐ity of ELISA were increased to 88 .8% (parametric method) .In the comparison of the parametric method and the non‐parametric method ,the obtained areas under the curve(AUC) was 0 .923 5(parametric method) ,their results were basically consistent .Conclu‐sion Although above results indicate that the detection results of ELISA reagent are different from those of WB ,but adjusting the cut off value can increase its sensitivity and specificity ,thus increases the reliability of diagnosis result .

Objective To investigate the expression levels of interferon-inducible genes (IFIT1,IFIT4,OAS1,OASL,ISG15) in the peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus(SLE).and the relations between these genes expression levels and disease activity are explored.Methods Sybr green dye based real-time quantitative PCR method was used to detect the expression levels (indicated as-△△Ct value) of WIT1,IFIT4.OAS1,OASL and ISG15 in 76 patients with SJJE and 54 controls.Their expression levels were compared with erythroeyte sedimentation rate (ESR),serum C reactive protein (CRP),complement C3,C4.antinuclear antibody (ANA).anti-double stranded DNA antibody.The associations between the expression levels of IFIT1,IFIT4,OASI.OASL,ISG15,ESR,CRP,complement C3,C4,ANA,anti-double stranded DNA antibody and SLEDAI scores in patients with SLE were analyzed.Results ① The expression levels of WIT1,IFIT4,OAS1,OASL and ISG15 in the SLE patients were significantly higher than those of the normal controls (P＜0.01).The expression levels of IFIT1,IFIT4,OAS1,OASL and ISG15 in active SLE patients were higher than those of inactive SLE patients (P＜0.05).The real time expression levels of IFIT1,IFIT4,OAS1.OASL and ISG15 showed positive correlations with each other (r＞0.5,P＜0.05) in patients with SLE.② The expression levels of IFIT1,IFIT4,OAS1,OASL and ISG15 were positively correlated with the SLEDAI scores (r＞0.5,P＜0.05).③ There was no correlation between ESR,CRP,complement C3,C4,ANA and the expression levels of IFIT1,IFIT4,OAS1,OASL,ISG15,SLEDAI scores except anti-double stranded DNA antibody (r＞0.5.P＜0.05).Conclusion The expression levels of IFIT1,IFIT4,OAS1,OASL and ISG15 in patients with SLE are significantly higher than those of the normal controls,and positively associated with SLEDAI scores,so they are helpful in evaluating SLE disease activity and severity.IFIT1,IFIT4,OAS1,OASL and ISG15 genes may be the potential treating targets for SLE.

Objective:To screen the neutralizing epitope of enterovirus 71 (EV71) and determine the specific minimum amino acid sequence that triggers immunity for providing a theoretical basis for the development of synthetic peptide vaccines.Methods:EV71 neutralizing antibody-specific binding clones were panned and sequenced using a phage display random 12-peptide library to obtain the key sequences of neutralizing epitopes. A series of peptides containing the key sequences with N-terminal acetylation (AC) and C-terminal linking to Keyhole limpet hemocyanin (KLH) were synthesized. Serum samples were collected after immunizing mice with the modified peptides. Then the immunogenicity of the peptides and the neutralizing activity of serum samples were analyzed by Western blot, ELISA and neutralization test.Results:After three rounds of panning, cloning and sequencing, KQEKDL was identified as the key motif. The serum samples collected from the mice immunized with the modified series of peptides containing key motifs had different degrees of binding ability to EV71 and VP1 protein. The serum samples of mice immunized the synthetic peptide containing only the minimum key motif (AC-KQEKDL-KLH) had the strongest response to the other three peptides and EV71 and the highest neutralizing titer.Conclusions:The EV71 neutralizing epitope was successfully screened using the phage display random peptide library. The key motif of KQEKDL might be the specific minimum amino acid sequence that triggered the immune system. This study provides a theoretical basis for better understanding the immune response mechanism, evaluating the immunogenicity of the antigens and further research and development of polypeptide vaccines.

Objective: To evaluate whether simultaneous vaccination with live attenuated polio vaccine affects the immunogenicity of live attenuated rotavirus (RV) vaccine. Methods: Rotarix produced by GlaxoSmithKline was used as the research object. Two doses of Rotarix were orally administered on day 0 and month 1, and oral live attenuated polio vaccine (OPV) was administered on day 0, month 1 and month 2 according to the national vaccination plan. Healthy infants aged 6 to 16 weeks were randomly divided into two groups: interval vaccination group (Rotarix and OPV were vaccinated on different days) and simultaneous vaccination group (Rotarix and OPV were vaccinated on the same day). Serum samples were collected on day 0, month 2 and month 12, and serum RV-IgA was measured by enzyme linked immunosorbent assay. Statistical analysis was performed to evaluate whether there were statistical differences in the seroconversion rate and level distribution of RV-IgA between the two groups. Results: The seroconversion rate of serum RV-IgA in month 2 was 73.84% in the interval vaccination and 63.95% in the simultaneous vaccination group, and the difference between them was statistically significant (P<0.05). The geometric mean concentrations (GMC) of RV-IgA were 97 EU/ml and 90 EU/ml, respectively (P>0.05). Compared with the simultaneous vaccination group, the seroconversion rate and GMC of serum RV-IgA in month 12 were higher in the interval vaccination group, and the differences were statistically significant (P<0.05). Conclusions Simultaneous vaccination with live attenuated polio vaccine would affect the immune response of live attenuated rotavirus vaccine, especially the maintenance of RV-IgA antibody level.

Objective To validate a cell infection-based quantitative RT-PCR for evaluating the potency of rotavirus vaccine. Methods According to the ICH ( the International Council for Harmonization) Harmonised Tripartite Guideline, the method was validated for its specificity, accuracy, precision, linearity and robustness. Results The method had good specificity as it could only amplify and detect the corre-sponding type of rotavirus strain. The recovery rates for determining the potency against rotaviruses of G2, G3 and G4 types were 97％ to 108％. The percent coefficient of variation ( CV) of both intra-plate and in-ter-plate precision was≤2. 62％, while the intraday and interday CV was≤1. 76％ and≤2. 27％, respec-tively. The CV between the two experimenters was≤7. 68％. The linearity range of the method was 4. 4-6. 5 UI for G2 type rotavirus, 3. 9-8. 3 UI for G3 type and 3. 5-8. 1 UI for G4 type. Good robustness was observed using the cells of 140 to 160 generations. Conclusions The cell infection-based quantitative RT-PCR was shown to have satisfactory specificity, accuracy, precision, linearity and robustness, suggesting that it was a suitable method for evaluating the potency of multivalent rotavirus live vaccines.