1.Function of ubiquitin-specific protease 47 in regulating rabies virus infection
Yannan ZHANG ; Mengyang WU ; Chongyang WANG ; Haomiao DONG ; Xin GUO ; Yidi GUO ; Maolin ZHANG
Chinese Journal of Veterinary Science 2025;45(2):266-273
This study aims to inquire about the fluctuations of ubiquitin-specific protease 47 on neu-roblastoma cells(Neuro-2a,N2a)infected by rabies virus(RABV).USP47 expression levels were detected after RABV infection in N2a cells through RT-qPCR,protein immunoblotting,and virus titer determination.The levels of RABV nucleoprotein and phosphoprotein gene and protein,and RABV titers in supernatants were analyzed during overexpression and knockdown of USP47.The results showed that RABV infection increased USP47 gene level in N2a cells.When overexpression of USP47,the levels of RABV N and P were increased,and the virus titers were also improved.Mo-reover,the level of interleukin-6(IL-6)genes decreased.Knocking down USP47 expression reduced levels of RABV N and P genes and proteins,lowered the virus titer,and elevated the IL-6 gene lev-el.The results suggest that USP47 promotes RABV infection and suppresses IL-6 expression.This finding lays the foundation for further investigation into the molecular mechanisms by which USP47 regulates RABV infection.
2.Establishment of double-antigen sandwich chemiluminescent enzyme immunoassay for antibody detection against classical swine fever virus Erns antigen
Zihan YANG ; Zhongdi LIU ; Yixiao ZHANG ; Qingshan ZUO ; Qichao SONG ; Zunbao WANG ; Yidi GUO ; Changchun TU ; Wenjie GONG
Chinese Journal of Veterinary Science 2025;45(9):1834-1842
To establish a highly specific,sensitive,and efficient method for detecting antibodies a-gainst the Erns protein of classical swine fever virus(CSFV),and to distinguish CSFV vaccine strains from wild strains infections in combination with the E2 subunit vaccine.The purified Erns protein of the CSFV expressed by baculovirus was conjugated to carboxylated magnetic beads as a solid-phase carrier and horseradish peroxidase(HRP),separately.A double-antigen sandwich chemiluminescent enzyme immunoassay(CLEIA)was developed by optimizing various reaction parameters using a fully automated chemiluminescence analyzer.This method was then applied to quantitatively detect Erns protein antibodies in sera from pigs infected with prevalent strains and those immunized with the CSFV E2 subunit vaccine and challenged with field strains.The results showed that the optimal conditions for coupling protein-to-magnetic bead were as follows:coupling buffer pH of 8.0,a protein coupling amount of 2.5 mg/g,blocking solution of 10%BSA,serum sample volume of 20 μL.The optimal dilution of enzyme-labeled antigen was at 1:500 with a one-step reaction time of 15 minutes.The cutoff value of the established CLEIA method for detecting CSFV Erns protein antibodies was 5.83 U/mL and a diagnostic sensitivity of 1:128.No cross-reac-tivity was observed with positive sera against African swine fever virus,pseudorabies virus,porcine circovirus type 2,porcine epidemic diarrhea virus,porcine reproductive and respiratory syndrome virus,or porcine gastroenteritis virus.Additionally,the method yielded negative results with sera from pigs immunized with the E2 subunit vaccine.In repeatability tests,the intra-assay coefficient of variation(CV)ranged from 0.77%to 11.56%,and the inter-assay CV ranged from 10.30%to 14.55%,both below 15%.The positive and negative concordance rates with a commercial CSFV Erns protein antibody detection kit were 95.24%and 92.71%,separately,with an overall concord-ance rate of 93.23%.The double-antigen sandwich chemiluminescence method established in this study exhibits high sensitivity,excellent repeatability,and suitability for automated detection,making it applicable for serological differentiation between CSFV E2 subunit vaccination and infec-tion with prevalent strains.
3.Establishment of double-antigen sandwich chemiluminescent enzyme immunoassay for antibody detection against classical swine fever virus Erns antigen
Zihan YANG ; Zhongdi LIU ; Yixiao ZHANG ; Qingshan ZUO ; Qichao SONG ; Zunbao WANG ; Yidi GUO ; Changchun TU ; Wenjie GONG
Chinese Journal of Veterinary Science 2025;45(9):1834-1842
To establish a highly specific,sensitive,and efficient method for detecting antibodies a-gainst the Erns protein of classical swine fever virus(CSFV),and to distinguish CSFV vaccine strains from wild strains infections in combination with the E2 subunit vaccine.The purified Erns protein of the CSFV expressed by baculovirus was conjugated to carboxylated magnetic beads as a solid-phase carrier and horseradish peroxidase(HRP),separately.A double-antigen sandwich chemiluminescent enzyme immunoassay(CLEIA)was developed by optimizing various reaction parameters using a fully automated chemiluminescence analyzer.This method was then applied to quantitatively detect Erns protein antibodies in sera from pigs infected with prevalent strains and those immunized with the CSFV E2 subunit vaccine and challenged with field strains.The results showed that the optimal conditions for coupling protein-to-magnetic bead were as follows:coupling buffer pH of 8.0,a protein coupling amount of 2.5 mg/g,blocking solution of 10%BSA,serum sample volume of 20 μL.The optimal dilution of enzyme-labeled antigen was at 1:500 with a one-step reaction time of 15 minutes.The cutoff value of the established CLEIA method for detecting CSFV Erns protein antibodies was 5.83 U/mL and a diagnostic sensitivity of 1:128.No cross-reac-tivity was observed with positive sera against African swine fever virus,pseudorabies virus,porcine circovirus type 2,porcine epidemic diarrhea virus,porcine reproductive and respiratory syndrome virus,or porcine gastroenteritis virus.Additionally,the method yielded negative results with sera from pigs immunized with the E2 subunit vaccine.In repeatability tests,the intra-assay coefficient of variation(CV)ranged from 0.77%to 11.56%,and the inter-assay CV ranged from 10.30%to 14.55%,both below 15%.The positive and negative concordance rates with a commercial CSFV Erns protein antibody detection kit were 95.24%and 92.71%,separately,with an overall concord-ance rate of 93.23%.The double-antigen sandwich chemiluminescence method established in this study exhibits high sensitivity,excellent repeatability,and suitability for automated detection,making it applicable for serological differentiation between CSFV E2 subunit vaccination and infec-tion with prevalent strains.
4.Function of ubiquitin-specific protease 47 in regulating rabies virus infection
Yannan ZHANG ; Mengyang WU ; Chongyang WANG ; Haomiao DONG ; Xin GUO ; Yidi GUO ; Maolin ZHANG
Chinese Journal of Veterinary Science 2025;45(2):266-273
This study aims to inquire about the fluctuations of ubiquitin-specific protease 47 on neu-roblastoma cells(Neuro-2a,N2a)infected by rabies virus(RABV).USP47 expression levels were detected after RABV infection in N2a cells through RT-qPCR,protein immunoblotting,and virus titer determination.The levels of RABV nucleoprotein and phosphoprotein gene and protein,and RABV titers in supernatants were analyzed during overexpression and knockdown of USP47.The results showed that RABV infection increased USP47 gene level in N2a cells.When overexpression of USP47,the levels of RABV N and P were increased,and the virus titers were also improved.Mo-reover,the level of interleukin-6(IL-6)genes decreased.Knocking down USP47 expression reduced levels of RABV N and P genes and proteins,lowered the virus titer,and elevated the IL-6 gene lev-el.The results suggest that USP47 promotes RABV infection and suppresses IL-6 expression.This finding lays the foundation for further investigation into the molecular mechanisms by which USP47 regulates RABV infection.
5.Preparation of polyclonal antibodies against VP8 protein of porcine rotavirus A and determination of neutralizing antibody titers
Jiachao XU ; Guangli HU ; Qingqing WU ; Xiaomei PAN ; Sun HE ; Yidi GUO ; Changchun TU ; Wenjie GONG
Chinese Journal of Veterinary Science 2025;45(6):1109-1116,1131
This study investigates the feasibility of the VP8*protein as a subunit vaccine target for porcine rotavirus A(PoRVA),a major causative agent of diarrhea in piglets.The VP8* genes of PoRVA P[13]and P[23]genotype strains were amplified by RT-PCR.These genes were then liga-ted into the pET-28a(+)vector,yielding recombinant plasmids pET-28a-XJWF1-VP8*-P[23]and pET-28a-ShXYW13-VP8*-P[13].These plasmids were subsequently transformed into BL21(DE3)competent cells.The VP8*protein,induced by IPTG,was purified using affinity chroma-tography,and its expression and purification were verified by SDS-PAGE and Western blot.The purified VP8* protein was used to immunize mice,and serum samples were collected after three immunizations.Cross-neutralization assays were conducted to evaluate the ability of the VP8*protein immune serum to neutralize different genotype strains.The results demonstrated the ex-pression of soluble VP8*protein,with SDS-PAGE and Western blot analyses showing that the purified VP8*protein existed in both monomeric(27 kDa)and homodimeric(54 kDa)forms.ELISA results indicated that high levels of antibodies were produced in mice immunized with VP 8*-P[13]and VP8*-P[23]after three immunizations.Serum cross-neutralization assays revealed that the neutralizing titers of PoRVA VP8*-P[13]and VP8*-P[23]immune sera against homol-ogous genotype strains ranged from 1∶4 800 to 1∶19 200,significantly higher than those against heterologous genotype strains(1∶1 200).This suggests that the VP8*protein of different geno-type strains exhibits both antigenic conservation and distinct variability.The data obtained in this study provide a solid foundation for further exploration of the antigenic structure of the PoRVA VP8* protein and the development of novel subunit vaccines.
6.Distribution of street rabies virus in salivary glands of dogs and mice following ex-perimental infection
Chongyang WANG ; Danwei ZHANG ; Yannan ZHANG ; Yuping LIU ; Xin GUO ; Yidi GUO ; Maolin ZHANG
Chinese Journal of Veterinary Science 2025;45(6):1178-1185
The rabies virus(RABV)that causes rabies mainly attacks the peripheral and central nervous systems.In the later stages of infection,it is scattered in the salivary glands and transmit-ted to other susceptible animals through infectious saliva.To study dispersion of the RABV in the three pairs of salivary gland tissues,the street strain PB4 of the RABV was inoculated into 21-day-old female mice through the hind limb muscles.During the moribund stage of the mice,the sublin-gual gland,submandibular gland and parotid gland were collected,respectively.The TCID50 titer of RABV in the three kinds of glands of the mice and the copy number of the RABV N gene were de-tected,and RABV in different salivary glands was observed by immunofluorescence.The results showed that PB4 was dispersed in all three kinds of salivary glands of the mice,with the largest a-mounts in the parotid gland,followed by the submandibular gland,and the lowest amount in the sublingual gland.Three-month-old dogs were inoculated with PB4 through the cranial cavity,and saliva were collected every 12 h after inoculation.The saliva samples were detected by TCID50 and RT-qPCR.And during the moribund stage of the dogs when the disease occurred,the three pairs of salivary glands were collected.Through the determination of the TCID50 titer,RT-qPCR and immu-nofluorescence detection,it was demonstrated that among the three different salivary glands of the dogs,the largest amount of PB4 was found in the parotid gland and the lowest in the sublingual gland.Our results in mice and dogs clearly proved that the parotid gland was consistently found to exhibit the highest content of street RABV among the three major salivary glands,which could en-rich experimental data for analyzing the dispersion of RABV in the salivary glands and interpreta-tion of the intermittent secretion of saliva in clinically rabid dogs.
7.Preparation of polyclonal antibodies against VP8 protein of porcine rotavirus A and determination of neutralizing antibody titers
Jiachao XU ; Guangli HU ; Qingqing WU ; Xiaomei PAN ; Sun HE ; Yidi GUO ; Changchun TU ; Wenjie GONG
Chinese Journal of Veterinary Science 2025;45(6):1109-1116,1131
This study investigates the feasibility of the VP8*protein as a subunit vaccine target for porcine rotavirus A(PoRVA),a major causative agent of diarrhea in piglets.The VP8* genes of PoRVA P[13]and P[23]genotype strains were amplified by RT-PCR.These genes were then liga-ted into the pET-28a(+)vector,yielding recombinant plasmids pET-28a-XJWF1-VP8*-P[23]and pET-28a-ShXYW13-VP8*-P[13].These plasmids were subsequently transformed into BL21(DE3)competent cells.The VP8*protein,induced by IPTG,was purified using affinity chroma-tography,and its expression and purification were verified by SDS-PAGE and Western blot.The purified VP8* protein was used to immunize mice,and serum samples were collected after three immunizations.Cross-neutralization assays were conducted to evaluate the ability of the VP8*protein immune serum to neutralize different genotype strains.The results demonstrated the ex-pression of soluble VP8*protein,with SDS-PAGE and Western blot analyses showing that the purified VP8*protein existed in both monomeric(27 kDa)and homodimeric(54 kDa)forms.ELISA results indicated that high levels of antibodies were produced in mice immunized with VP 8*-P[13]and VP8*-P[23]after three immunizations.Serum cross-neutralization assays revealed that the neutralizing titers of PoRVA VP8*-P[13]and VP8*-P[23]immune sera against homol-ogous genotype strains ranged from 1∶4 800 to 1∶19 200,significantly higher than those against heterologous genotype strains(1∶1 200).This suggests that the VP8*protein of different geno-type strains exhibits both antigenic conservation and distinct variability.The data obtained in this study provide a solid foundation for further exploration of the antigenic structure of the PoRVA VP8* protein and the development of novel subunit vaccines.
8.Distribution of street rabies virus in salivary glands of dogs and mice following ex-perimental infection
Chongyang WANG ; Danwei ZHANG ; Yannan ZHANG ; Yuping LIU ; Xin GUO ; Yidi GUO ; Maolin ZHANG
Chinese Journal of Veterinary Science 2025;45(6):1178-1185
The rabies virus(RABV)that causes rabies mainly attacks the peripheral and central nervous systems.In the later stages of infection,it is scattered in the salivary glands and transmit-ted to other susceptible animals through infectious saliva.To study dispersion of the RABV in the three pairs of salivary gland tissues,the street strain PB4 of the RABV was inoculated into 21-day-old female mice through the hind limb muscles.During the moribund stage of the mice,the sublin-gual gland,submandibular gland and parotid gland were collected,respectively.The TCID50 titer of RABV in the three kinds of glands of the mice and the copy number of the RABV N gene were de-tected,and RABV in different salivary glands was observed by immunofluorescence.The results showed that PB4 was dispersed in all three kinds of salivary glands of the mice,with the largest a-mounts in the parotid gland,followed by the submandibular gland,and the lowest amount in the sublingual gland.Three-month-old dogs were inoculated with PB4 through the cranial cavity,and saliva were collected every 12 h after inoculation.The saliva samples were detected by TCID50 and RT-qPCR.And during the moribund stage of the dogs when the disease occurred,the three pairs of salivary glands were collected.Through the determination of the TCID50 titer,RT-qPCR and immu-nofluorescence detection,it was demonstrated that among the three different salivary glands of the dogs,the largest amount of PB4 was found in the parotid gland and the lowest in the sublingual gland.Our results in mice and dogs clearly proved that the parotid gland was consistently found to exhibit the highest content of street RABV among the three major salivary glands,which could en-rich experimental data for analyzing the dispersion of RABV in the salivary glands and interpreta-tion of the intermittent secretion of saliva in clinically rabid dogs.
9.Status of prepackaged food intake and the association with growth and development in school aged children of Chengdu City
HE Chunlei, LIU Xueting, WANG Yidi, LI Danting, WANG Xiaoyu, CHENG Guo
Chinese Journal of School Health 2024;45(1):16-20
Objective:
To determine the association between the intake of five major types of prepackaged foods and the growth and development of school aged children, so as to provide a theoretical basis for guiding school aged children and their parents to make healthy prepackaged food choices.
Methods:
Based on data from the South West China Childhood Nutrition and Growth Cohort (SCCNG), 381 children (6-11 years of age) were selected by stratified cluster sampling. Dietary intake and pubertal development were collected using questionnaires, and anthropometric measurements were obtained. Children were followed up until November 2022. Binary Logistic regression models were used to analyze the prospective association between prepackaged food intake and the growth and development of school aged children.
Results:
The total intake of the five major types of prepackaged foods was 316.1 (197.1,501.4) g/d. After 2 years of follow up evaluations, 16.5% of school aged children were shown to be overweight and obese. Early spermarche occurred in 12.6% of boys and early menarche occurred in 15.4% of girls. The following findings were suggested after adjusting for the mothers education level, average gross monthly family income, whether or not the family had one child only, geographic area of residence, body mass index Z score, average duration of daily exercise, and total dietary energy intake: convenience food intake might increase the risk of early spermarche ( OR =9.37); fruit and vegetable intake might decrease the risk of early spermarche and menarche ( OR =0.33,0.17); and fish, poultry, meat, and egg intake might increase the risk of early menarche ( OR =7.59)( P <0.05). Intake of the five types of prepackaged foods was not associated with being overweight or obese after adjusting for confounders ( OR =1.40, 0.57, 0.73, 1.33,1.57, P >0.05).
Conclusions
The relationship between intake of the five major types of prepackaged foods and pubertal development is inconsistent and no significant correlation was detected between the intake of prepackaged foods and overweight or obese children. Nutrition education should be strengthened to help children and their parents choose healthy prepackaged foods.
10.Differences in gut microbiota among primary school students with different levels of sugar sweetened beverage consumption
Chinese Journal of School Health 2024;45(3):335-340
Objective:
To explore the differences in the gut microbiota of primary school students with different levels of sugar sweetened beverage intake, so as to provide scientific evidence for better identification of health risks in children and the development of targeted health policies.
Methods:
In June 2022, a total of 192 healthy primary school students from Chengdu were selected using a stratified cluster random sampling method. The sugar sweetened beverage intake was assessed through a dietary frequency questionnaire. Based on the median daily sugar sweetened beverage intake, primary school students were categorized into a low intake group ( n =96) and a high intake group ( n =96). The gut microbiota in fresh fecal samples from the two groups of primary school students was analyzed using 16S rRNA high throughput sequencing, and the diversity and community structure differences in the gut microbiota were compared.
Results:
Children in the low intake group had a sugar sweetened beverage intake of (21.3±1.6) mL/d, while the high intake group had an intake of (269.6±37.3) mL/d. Diversity analysis results showed that there were no statistically significant differences between the low intake and the high intake group in terms of α diversity metrics: Observed_otus index [298.50 (259.75, 342.25), 305.50 (244.25, 367.75)], Goods_coverage index [1.00 (1.00, 1.00), 1.00 (1.00, 1.00)], Chao index [304.18 (260.75, 348.78), 305.88 (245.68, 370.88)], Shannon index [5.88 (5.29, 6.45), 5.71 (4.89, 6.28)] and Simpson index [0.95 (0.91, 0.97), 0.94 (0.88, 0.97)] ( Z =-0.64, -0.76, -0.54, -1.76, -1.67, P >0.05). Furthermore, no statistically significant difference was observed in β diversity between the two groups ( R 2=0.006, P >0.05). At the genus level, the abundance of Blautia [0.033 (0.018, 0.055)] and Fusicatenibacter [0.009 (0.005, 0.015)] were higher in the low intake group compared to the high intake group [0.024 (0.013, 0.041),0.006 (0.003, 0.011)]and differences were statistically significant ( Z =-2.52, -2.81, P <0.05). LEfSe analysis highlighted intergroup differences primarily in Blautia, Fusicatenibacter and Sarcina( LDA= 3.56,3.12,3.53, P <0.05).
Conclusions
There is no significant difference in the diversity and overall structure of the gut microbiota in primary school students with different levels of sugar sweetened beverage intake. However, there are species variations at the genus level. The information can serve as a scientific basis for identifying health risks in primary school students and formulating targeted health strategies.


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