Objective To screen and identify the dengue virus-specific antigens,then establish the ELISA detection method for dengue virus antibody.Methods Using bioinformatic software DNAStar and ANTHEPROT to analyze the hydrophilicity,flexibility,surface probability and antigenicity of dengue virus type 1-4,Japanese encephalitis virus and Yellow fever virus M,E and NSI protein amino acid sequence and also consider the influence of secondary structure.Then in accordance with epitopes localion and amino acid sequence similarity,forecast the share and specific epitopes.Reference the sequence information of different dengue virus strains in GenBank to analyze the epitopes conservative.Based on the results of bioinformatic analysis,5 specific epitopes were amplified and inserted into prokaryotic expression vector pMAL-C2x or pET32a.Then the vectors was transferred into E.coli Rosetta( DE3 ).lsopropyl-β-D-thiogalactoside(IPTG) was used to induce the expression of gene segments.SDS-PAGE were used to identify the expression proteins,and the antigenicity were tested using Western blot.Using the antigen selected by Western blot,ELISA method for dengue virus antibody detection was established.Results Eighty shared epitopes and 25 specific epitopes were forecasted,and 5 antigenic fragments encloude analyzed epitopes from dengue virus type 2 and 3 were expressed in E.coli successfully.One dengue virus type 1-4 shared antigens (Den-Ag5),one dengue virus type 2 and 4 shared antigens( DenAg3),one dengue virus type 1-3 shared antigens(Den-Ag2) and two dengue virus type 1,2 and 4 shared antigens( Den-Ag1,Den-Ag4)were conformed using Western blot.Using antigens Den-Ag5,Den-Ag1 and DenAg2,the ELISA method for dengue virus antibody detection were established.Conclusion Based on the bioinformatic analysis and Western blot verification,5 dengue virus specific antigen were conformed,and the ELISA detection method for dengue virus antibody were established.

OBJECTIVETo screen and identify dengue virus type 2 specific antigens and establish an enzyme-linked immunosorbent assay (ELISA) for detecting dengue virus type 2 antibody.

METHODSUsing the bioinformatic software DNAstar and ANTHEPROT, we analyzed the hydrophilicity, flexibility, surface probability and antigenicity of dengue virus type 1-4, Japanese encephalitis virus, and Yellow fever virus M and E protein amino acid sequences, and also evaluated the influence of secondary structure. The specific epitopes of dengue virus type 2 were predicted according to the epitope location and amino acid sequence similarity, and the epitope conservation was assessed using the sequence information of different dengue virus type 2 strains in GenBank. Based on the results of bioinformatic analysis, 5 specific epitopes were amplified and inserted into the prokaryotic expression vector pET32a, which were transferred into E. coli Rosetta (DE3) for expression of the proteins. SDS-PAGE and Western blotting were used to identify the expressed proteins and test their antigenicities. The antigen selected by Western blotting was used to establish the ELISA system for dengue virus type 2 antibody detection.

RESULTSBioinformatic analysis predicted 8 possible dengue virus type 2 specific epitopes, and 6 of them were efficiently expressed in E. coli. Western blotting confirmed 1 dengue virus type 2 specific antigen, the ELISA system for dengue virus antibody detection was successfully established using this specific antigen.

CONCLUSIONWe have obtained a dengue virus type 2 specific antigen and established an ELISA system for detection of dengue virus type 2 antibody.

Antibodies, Viral ; immunology ; Antigens, Viral ; immunology ; Computational Biology ; Dengue Virus ; classification ; immunology ; isolation & purification ; Enzyme-Linked Immunosorbent Assay ; methods ; Humans ; Immunodominant Epitopes ; Software

Objective:To summarize the situation of dead newborns and their parents after parents gave up treatment, and analyze the reasons and emotional needs of parents who gave up treatment, so as to provide reference for reducing neonatal mortality and negative emotions of parents.Methods:A retrospective study was conducted to collect the data of neonates and mothers who died after giving up treatment reported in Hunan Children′s Hospital from January 2019 to December 2021. The general information, perinatal risk factors, and the incidence of in-hospital diseases were analyzed. Then, semi-structured interviews were conducted with parents of newborns who died after giving up treatment from February to December 2021. Understand why parents give up treatment and their emotional needs.Results:A total of 172 newborns died after giving up were included in the analysis, including 103 males (59.88%) and 74 premature infants (43.02%); Umbilical cord, placenta and amniotic fluid abnormalities were 21 cases (12.21%), 39 cases (22.67%) and 25 cases (14.53%), respectively. Birth asphyxia was 31 cases (18.02%), including severe asphyxia in 18 cases (10.46%); There were 21 (12.21%), 35 (20.35%) and 30 (17.44%) cases of maternal infection in the third trimester, hypertension in pregnancy and diabetes in pregnancy, respectively. The top three causes of death were septicemia (18.02%), congenital malformation (16.86%) and severe pneumonia (10.47%). The main reason why parents give up treatment was that the child′s disease was critical and irreversible, and parents had strong emotional needs for hospice care in their hearts.Conclusions:There are many high risk factors of perinatal death of newborns after giving up treatment. Sepsis is the primary cause of death, and strengthening perinatal health care is fundamental. Parents have a strong demand for hospice care, so it is of practical significance to implement family-centered hospice care model for such special newborns.

Objective:To investigate the antioxidant function of Mycoplasma pneumoniae MPN662 and analyze the key active sites, and to explore the role of MPN662 in the regulation of the production of reactive oxygen species (ROS) and superoxide dismutase (SOD) in THP-1 cells. Methods:pET28a(+ )- mpn662, recombinant mutant plasmids pET28a(+ )- mpn662-Ser 66 (the 66 th Cys was mutated to Ser) and pET28a(+ )- mpn662-Ala 66 (the 66 th Cys was mutated to Ala) were constructed, recombinant proteins rMPN662, rMPN662-Ser 66 and rMPN662-Ala 66 were expressed, identified, and purified. DTNB method was employed to analyze the MetO reduction activity of rMPN662 and recombinant mutant protein. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot were applied to examine the transcription level of the mpn662 gene and the expression level of MPN662 protein after Mycoplasma pneumoniae were stimulated with different concentrations of hydrogen peroxide (H 2O 2) or tert-butyl hydroperoxide (t-BHP), respectively. Fluorescent probes (DCFH-DA) and the total SOD activity detection kit were used to test the levels of intracellular ROS and SOD in THP-1 cells, which were pretreated with rMPN662, and then stimulated by Mycoplasma pneumoniae lipid-associated membrane proteins (LAMPs). Results:Mycoplasma pneumoniae rMPN662 could reduce MetO to Met, and the enzyme activities of mutant protein were significantly lower than those of rMPN662 protein. mpn662 gene mRNA transcription level and MPN662 protein expression level were significantly increased in a dose-dependent manner when Mycoplasma pneumoniae was stimulated with H 2O 2 and t-BHP. Treatment with rMPN662 before THP-1 cells were exposed to LAMPs could decrease the level of ROS and increase the production of SOD. Conclusions:Mycoplasma pneumoniae MPN662 can reduce MetO to Met, and Cys66 is the key amino acid for this activity. MPN662 can decrease the release of ROS and increase the production of SOD in Mycoplasma pneumoniae LAMPs stimulated THP-1 cells.