Early therapeutic interventions of traditional Chinese medicine in COVID-19 patients: A retrospective cohort study / 中西医结合学报

OBJECTIVE@#To observe the early interventions of traditional Chinese Medicine (TCM) on the conversion time of nucleic acid in patients with coronavirus disease 2019 (COVID-19), and find possible underlying mechanisms of action.@*METHODS@#A retrospective cohort study was conducted on 300 confirmed COVID-19 patients who were treated with TCM, at a designated hospital in China. The patients were categorized into three groups: TCM1, TCM2 and TCM3, who respectively received TCM interventions within 7, 8-14, and greater than 15 days of hospitalization. Different indicators such as the conversion time of pharyngeal swab nucleic acid, the conversion time of fecal nucleic acid, length of hospital stay, and inflammatory markers (leukocyte count, and lymphocyte count and percentage) were analyzed to observe the impact of early TCM interventions on these groups.@*RESULTS@#The median conversion times of pharyngeal swab nucleic acid in the three groups were 5.5, 7 and 16 d (P < 0.001), with TCM1 and TCM2 being statistically different from TCM3 (P < 0.01). TCM1 (P < 0.05) and TCM3 (P < 0.01) were statistically different from TCM2. The median conversion times of fecal nucleic acid in the three groups were 7, 9 and 17 d (P < 0.001). Conversion times of fecal nucleic acid in TCM1 were statistically different from TCM3 and TCM2 (P < 0.01). The median lengths of hospital stay in the three groups were 13, 16 and 21 d (P < 0.001). TCM1 and TCM2 were statistically different from TCM3 (P < 0.01); TCM1 and TCM3 were statistically different from TCM2 (P < 0.01). Both leucocyte and lymphocyte counts increased gradually with an increase in the length of hospital stay in TCM1 group patients, with a statistically significant difference observed at each time point in the group (P < 0.001). Statistically significant differences in lymphocyte count and percentage in TCM2 (P < 0.001), and in leucocyte count (P = 0.043) and lymphocyte count (P = 0.038) in TCM3 were observed. The comparison among the three groups showed a statistically significant difference in lymphocyte percentage on the third day of admission (P = 0.044).@*CONCLUSION@#In this study, it was observed that in COVID-19 patients treated with a combination of Chinese and Western medicines, TCM intervention earlier in the hospital stay correlated with faster conversion time of pharyngeal swab and fecal nucleic acid, as well as shorter length of hospital stay, thus helping promote faster recovery of the patient. The underlying mechanism of action may be related to improving inflammation in patients with COVID-19.

Rescue of the recombinant infectious bronchitis virus with the ectodomain region of H120 spike glycoprotein / 病毒学报

To explore the expression potential of heterogeneous genes using the backbone of infectious bronchitis virus (IBV) Beaudette strain, the ectodomain region of the Spike gene (1,302 bp) of IBV H120 strain was amplified by RT-PCR and replaced into the corresponding location of the IBV Beaudette strain full-length cDNA. This recombinant was designated as BeauR-H120(S1). BeauR-H120(S1) was directly used as the DNA template for the transcription of viral genomic RNA in vitro. Then, the transcription product was transfected into Vero cells by electroporation. At 48 h post-transfection, the transfected Vero cells were harvested, and passaging continued. A syncytium was not observed until the recombinant virus had passed through four passages. The presence of rBeau-H120(S1) was verified by the detection of the replaced ectodomain region of the H120 Spike gene using RT-PCR. Western blot analysis of rBeau-H120 (S1)-infected Vero cell lysates demonstrated that the nucleocapsid (N) protein was expressed, which implied that rBeau-H120(S1) could propagate in Vero cells. The TCIDs0 and EIDs0 data demonstrated that the titer levels of rBeau-H120(S1) reached 10(590+/-0.22)TCID50/mL and 10(6.13+/-0.23)EID50/mL in Vero cells and 9-day-old SPF chicken embryos, respectively. Protection studies showed that the percentage of antibody-positive chickens, which were vaccinated with rBeau-H120(S1) at 7 days after hatching, rose to 90% at 21 days post-inoculation. Inoculation provided an 85% rate of immune protection against a challenge of the virulent IBV M41 strain (103EID50/chicken). This recombinant virus constructed using reverse genetic techniques could be further developed as a novel genetic engineering vaccine against infectious bronchitis.

Construction and sequencing of full-length cDNA clone of swine vesicular disease virus strain HK'1/70 / 病毒学报

By RACE, 2 overlapping cDNA fragments (3'PCR and 5'PCR fragments) covering the full genome of swine vesicular disease virus strain HK'1/70 were amplified from total RNA extracted from experimentally infected suckling mice. These fragments were cloned into pGEM-T Easy vector, respectively. 5'PCR fragment was digested by enzymes of Aat II and BssH II, and the Aat II-BssH II-digested 5'PCR fragment was obtained and cloned into the recombinant pGEM-T Easy vector containing 3'PCR fragment,the recombinant plasmid encoding full-length cDNA of SVDV HK'I/70 strain was then obtained and sequenced. The results showed that the complete genome of HK'1/70 was 7401 nucleotides (nts) long (excluding the poly (A) tract) which encodes a single polyprotein of 2185 amino acids, a 5'u ntranslating region (UTR) of 743 nts, a 3'UTR of 102 nts and a poly (A) tail at least 74 adenines. T' promoter was added at the 5'e nd of the full-length cDNA and an additional Pspl406I restriction site was added at the 3'e nd of poly (A) tail. The nucleotide and amino acid sequences were compared and phylogenetic analysis was used to examine the evolutionary relationships. The results showed that HK'1 /70 belonged to the second antigenic group. SVD virus was antigenically closely related to Coxsackie B5 virus, and located on the branches of CB5 evolutionary tree. Successful construction of full-length cDNA clone of SVDV HK'1/70 strain lays foundation for rescuing SVDV effectively and enables further research of SVDV on molecular level.

Prediction of Secondary Structure and B Cell Epitope for Capsid Protein of SVDV / 中国生物工程杂志

The secondary structure of Capsid protein was predicted by the methods of Chou-Fasman,Garnier-Robson and Karplus-Schultz based on the sepuence of capsid protein gene of Swine Vesicular Disease Virus (SVDV) and hydrophilicity. Surface probility plot and antigenic index for capsid protein were obtained by the methods of Kyte-Doolittle, Emini and Jameson-wolf, respectively, Combining the results according to these methods, the B cell epitopes for capsid protein of SVDV were predicted. The results showed that there are much flexible region such as coil region and turn region in capsid protein of SVDV, there are more predominant B cell epitopes in VP1 than in VP2 and VP3. This study would be helpful for identification of B cell epitopes for capsid protein using experimental methods and research of reverse vaccine of SVDV.

Expression of recombinant plasmid pcDNA3.1/P12X3C with multi-genes of foot-and-mouth disease virus in BHK-21 cells / 生物工程学报

In order to obtain the gene P12X3C of Foot-and-Mouth Disease Virus (FMDV) that includes full length P1, 2A, 3C and a part of 2B, the site mutation strategy was used. After being digested by Kpn I and Xba I respectively, the gene P12X3C was cloned into the pcDNA3.1 (+) expression vector. The recombinant plasmid was checked by restriction enzyme analysis and nucleic acid sequencing, and then named pcDNA3.1/P12X3C. Further, BHK-21 cells was transfected with pcDNA3.1/P12X3C by using lipoid. The proteins of Foot-and-Mouth Disease Virus, which were expressed in BHK-21 cells, were confirmed by sandwich-ELISA and fluoroscopy. The result shows the gene P12X3C is cloned into eukaryotic expression plasmid, and the recombinant eukaryotic expression plasmid pcDNA3.1/P12X3C could express proteins of Foot-and-Mouth Disease Virus in BHK-21 cells, which have immunocompetence. This study demonstrates that delivery of a recombinant eukaryotic expression plasmid containing P12X3C coding regions results in the assembly of FMDV capsid structures, which will offer experimental base to DNA vaccine of FMDV.