In order to probe the biological function of O-GlcNAc and the pathogenesis of associated diseases, it is essential to prepare a potent and specific O-GlcNAcase (OGA) antibody. Based on protein sequence analysis, we found N terminal 1-350 amino acids of OGA (sOGA) has high antigenicity and hydrophilicity and then constructed it into plasmid pET28a vector. First, we optimized the expression of sOGA in Escherichia coli BL21(DE3) (0.05 mmol/L IPTG, 10 hours) and purified it with the Ni-NTA affinity chromatography and size exclusion chromatography respectively. SDS-PAGE verified the molecular weight (45 kDa) and the purity (>95%) of sOGA and the purified protein was subjected to immunize New Zealand rabbits. Finally, we obtained OGA polyclonal antibody by affinity purifying the antiserum with CNBr-activated Sepharose 4B beads. Western blotting and ELISA assay showed that this antibody could recognize three OGA isoforms with high specificity and the sensitivity was 0.11 ng/mL (the titer was 1:80 000). These results indicated the prepared polyclonal antibody of OGA can be used for the biological function study of OGA.
Animals ; Antibodies ; metabolism ; Antigen Presentation ; immunology ; Escherichia coli ; genetics ; metabolism ; Genetic Vectors ; genetics ; Humans ; Immunization ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; beta-N-Acetylhexosaminidases ; biosynthesis ; genetics ; immunology

Objective:To study the influence of different feeding patterns on mother-to-child transmission (MTCT) of hepatitis B virus (HBV) in pregnant women with high viral loads who received antiviral medication during pregnancy to the day of delivery.Methods:This prospective cohort study was conducted in Beijing You'an Hospital. From January 1, 2019, to March 31, 2020, and 574 pregnant women with positive hepatitis B surface antigen (HBsAg) and HBV DNA>2×10 5 IU/ml were enrolled. All participants received tenofovir, telbivudine, lamivudine, or propofol tenofovir from 24-28 weeks of gestation and discontinued on the day of delivery, and their neonates were postnatally given routine passive-active immunoprophylaxis. Based on the feeding patterns, the subjects were divided into three groups: breastfeeding ( n=257), bottle-feeding ( n=241) and mixed feeding groups ( n=76). The follow-up data were obtained from liver functions and HBV DNA level of the mothers at 6-8 weeks postpartum and HBV serological markers of infants at 7-12 months. One-way ANOVA, Student-Newman-Keuls, Chi-square test or Fisher exact test, and repeated measures ANOVA were used to analyze the data. Results:The average maternal HBV DNA levels before antiviral treatment did not differ significantly between the three groups [(7.90±0.67), (7.82±0.70), (7.83±0.70) log 10 IU/ml, F=0.912, P>0.05]. HBV DNA level before delivery in the mixed feeding group was slightly lower than that in the breastfeeding and bottle-feeding group [(3.87 ±1.08) vs (4.21±1.17) and (4.30±1.28) log 10 IU/ml, q= 3.052 and 3.831, both P<0.05], while the comparison between the latter two groups showed no significant differences ( P>0.05). After delivery, HBV DNA level in the bottle-feeding group was slightly lower than that in the breastfeeding group [(7.42±0.93) vs (7.69±0.90) log 10 IU/ml, q=4.583, P<0.05]. Among 580 infants (including six pairs of twins), only one bottle-fed infant (0.4%, 1/243) was infected with HBV through MTCT, and none in the breastfeeding or mixed feeding group ( P=0.553). Conclusions:For pregnant women with high viral loads of HBV who have received antiviral medication during pregnancy, although HBV DNA level will rebound after discontinuation upon delivery, breastfeeding is recommended considering it does not increase the risk of MTCT.