The spike (S) glycoprotein of HCoV-NL63 is a major target in the development of diagnostic assays and vaccines, but its antigenic and immunogenic properties remain unclear. Four fragments coding spike proteins (S1, S2, RL and RS) from HCoV-NL63 were amplified and cloned into the expression vector derived from vaccinia virus (Tiantan strain), and recombinant vaccinia viruses expressing four segments of spike proteins were generated (vJSC1175-S1; vJSC1175-S2; vJSC1175-RL; vJSC1175-RS), respectively. Their expression location in cell and level were characterized using indirect immune fluorescence assay (IFA) and Western-Blot, respectively. The expressions of four segments of spike proteins in recombinant vaccinia viruses were showed at appropriate level and with posttranslational modification (glycosylation), and S1, RL and RS were mainly distributed in the cell membrane, while the S2 was mainly distributed in the cytoplasm. Our results provide a basis for further exploring diagnostic role and vaccine development of different spike segments from HCoV-NL63.
Base Sequence ; Blotting, Western ; Coronavirus NL63, Human ; chemistry ; Fluorescent Antibody Technique, Indirect ; Humans ; Membrane Glycoproteins ; biosynthesis ; genetics ; Molecular Sequence Data ; Plasmids ; Recombinant Proteins ; biosynthesis ; Spike Glycoprotein, Coronavirus ; Vaccinia virus ; genetics ; Viral Envelope Proteins ; biosynthesis ; genetics

Objective:To evaluate the effects of a booster immunization with a candidate tetanus toxoid, reduced diphtheria toxoid and acellular pertussis combined vaccine (Tdap) in a rat model after primary vaccination with diphtheria, tetanus, acellular pertussis and Sabin strain inactivated poliovirus combined vaccine (DTacP-sIPV) or diphtheria, tetanus, acellular pertussis, inactivated poliovirus and haemophilus type b combined vaccine (DTacP-IPV/Hib) for further preclinical study.Methods:Wistar rats were randomly divided into three groups and respectively immunized with a self-developed DTacP-sIPV, a marketed DTacP-IPV/Hib and normal saline at 0, 1, and 2 months of age. Serum levels of antibody against each component in each group were detected before immunization and after each dose. A booster dose of the candidate Tdap was given 10 months after primary immunization. Serum levels of antibody against each component in each group were detected before, 1 month and 6 months after the booster immunization.Results:One month after three doses of primary immunization, the geometric mean titers (GMT, Log2) of antibodies against diphtheria toxoid (DT), tetanus toxoid (TT), pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (PRN) in the DTacP-sIPV group were 17.41, 18.34, 18.11, 19.93 and 13.91, respectively, and the seroconversion rates of these components all reached 100%. Ten months after primary immunization, the GMTs of antibodies against DT, TT, PT, FHA and PRN decreased to 15.17, 14.26, 13.60, 14.51 and 10.39, respectively, and the seroconversion rates remained above 89%. One month after booster immunization, the GMTs of antibodies against DT, TT, PT and FHA in the DTacP-sIPV and DTacP-IPV/Hib groups were 16.49/17.26, 16.80/17.63, 16.70/17.74 and 18.48/19.26, respectively, and the seroconversion rates of these components all reached 100% with no significant difference between the two groups ( P>0.05). The GMTs of anti-PRN antibody in the DTacP-sIPV and DTacP-IPV/Hib groups were 13.07 and 11.00, and the seroconversion rates were 100% and 88%, which were higher in the DTacP-sIPV group than in the DTacP-IPV/Hib group ( P<0.05). Six months after booster immunization, the GMTs of antibodies against DT, TT, PT, FHA and PRN in the DTacP-sIPV and DTacP-IPV/Hib groups decreased to 15.74/14.87, 15.07/15.14, 14.84/15.73, 16.62/16.37 and 11.44/9.96, respectively, and the seroconversion rates remained above 88%. Conclusions:Booster vaccination with the candidate Tdap vaccine induces humoral immune response following primary immunization with DTacP-sIPV or DTacP-IPV/Hib in the Wistar rat model, while the antibody titer decreases with time.

Objective To measure the peripheral dose distributions of the mobile head cone beam computed tomography (CBCT) and evaluate the impact of CBCT on the surrounding personnel and environment, and provide data support for clinical radiation protection management. Methods Combined with the structural characteristics of CBCT, AT1123 was used in the direction of 0° (counterclockwise), 45°, 90°, 135°, 180°, 225°, 270° and 315° in front of CBCT to measure the ambient dose equivalent rate of 30 cm, 80 cm and 130 cm away from the ground when the equipment was normally out of the beam, and the boundary of the temporary control area was drawn. At the same time, the dose level behind the lead screen 1 m away from the external surface of the equipment was measured and analyzed. Results The dose field around CBCT was symmetrically distributed with the dividing line of 0° and 180°, and the radiation dose level of 5.5 m in the direction of 0°, 3.5 m in the direction of 45°, 0.5 m in the direction of 90° and within 1.0 m in the direction of 180° (inside the "spoon" type) was higher than 2.5 μSv/h. The radiation dose levels of CT aperture 0° (straight forward), 45° and 315° behind the lead screen 1 m away from the equipment surface were 0.37 μSv/h, 0.22 μSv/h and 0.54 μSv/h, respectively. Conclusion The results show that the radiation dose around the mobile head cone beam CT is in a low dose level, the distribution of the dose field can provide necessary reference for the administrative and medical personnel to strengthen the radiation safety management. At the same time, it is suggested that lead screens should be set up in the clinical use of mobile CT to ensure the health and safety of the surrounding people and the environment.