[Change in serum IgG antibody during the recovery stage of Omicron variant infection in children: an analysis of 110 cases]. / 110ä¾‹å„¿ç«¥å¥¥å¯†å ‹æˆŽå˜å¼‚æ ªæ„ŸæŸ“æ¢å¤æœŸè¡€æ¸ IgG抗体变化.

OBJECTIVES: To investigate the serum level of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific RBD IgG antibody (SARS-CoV-2 IgG antibody for short) in children with SARS-CoV-2 Omicron variant infection during the recovery stage, as well as the protective effect of SARS-CoV-2 vaccination against Omicron infection. METHODS: A retrospective analysis was performed on 110 children who were diagnosed with coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 Omicron variant infection in Tianjin of China from January 8 to February 7, 2022. According to the status of vaccination before diagnosis, they were divided into a booster vaccination (3 doses) group with 2 children, a complete vaccination (2 doses) group with 90 children, an incomplete vaccination (1 dose) group with 5 children, and a non-vaccination group with 13 children. The clinical data and IgG level were compared among the 4 groups. RESULTS: The complete vaccination group had a significantly higher age than the non-vaccination group at diagnosis (P<0.05), and there was a significant difference in the route of transmission between the two groups (P<0.05). There were no significant differences among the four groups in sex, clinical classification, and re-positive rate of SARS-CoV-2 nucleic acid detection (P>0.05). All 97 children were vaccinated with inactivated vaccine, among whom 85 children (88%) were vaccinated with BBIBP-CorV Sinopharm vaccine (Beijing Institute of Biological Products, Beijing, China). At 1 month after diagnosis, the booster vaccination group and the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05), and at 2 months after diagnosis, the complete vaccination group had a significantly higher level of SARS-CoV-2 IgG antibody than the non-vaccination group (P<0.05). For the complete vaccination group, the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis was significantly lower than that at 1 month after diagnosis (P<0.05). CONCLUSIONS: Vaccination with inactivated SARS-CoV-2 vaccine has a protective effect against Omicron infection in children. For children vaccinated with 2 doses of the vaccine who experience Omicron infection, there may be a slight reduction in the level of SARS-CoV-2 IgG antibody at 2 months after diagnosis. Citation:Chinese Journal of Contemporary Pediatrics, 2022, 24(7): 736-741.

N-acetylcholine receptors regulate cytokines expression and neutrophils recruitment via MAPK/ERK signaling in zebrafish.

N-acetylcholine receptors (AChRs) are mainly distributed in the postsynaptic membrane and have been widely studied for their control of muscle contraction by regulating neural action potentials. However, the influences of AChRs on immune responses and potential mechanisms remain unclear. Here, we used the advantages of live imaging of zebrafish to explore the regulation process of AChRs on inflammatory responses. Pharmacologically activating of the receptor, we found that the expression of pro-inflammatory cytokines il-1ß, il-6, tnf-α and il-8 was significantly up-regulated and neutrophil migration to injury sites was also significantly increased. However, these phenomena were reversed under antagonism of the receptor activity. Results showed that interfering with nAChRs functions did not significantly affect zebrafish motion behavior. Results also showed that activation and antagonism of nAChRs function could regulate the phosphorylation of ERK protein respectively. We further demonstrated that ERK participated in the regulation of AChRs in cytokines expression and neutrophils migration in zebrafish. This study preliminarily revealed the roles of AChRs in inflammatory processes and their potential mechanism, providing additional evidence of peripheral immune regulation by cholinergic receptors.

Cordycepin inhibits inflammatory responses through suppression of ERK activation in zebrafish.

As a natural extract, cordycepin has been shown to play important regulatory roles in many life activities. In the study, the effects of cordycepin on inflammatory responses and the underlying mechanisms was explored using a zebrafish model. In the model of LPS-induced inflammation, cordycepin was found to significantly inhibited the expression of pro-inflammatory cytokines such as tnf-α, il-1ß, il-6, and il-8. Using in vivo imaging model, cordycepin significantly inhibited fluorescent-labeled neutrophils migrating towards injury sites. Furthermore, results showed that the phosphorylation level of ERK protein dramatically decreased after cordycepin treatment. Meanwhile, the ERK inhibitor, PD0325901, significantly inhibited the expression of pro-inflammatory cytokines in LPS-induced inflammatory model and neutrophils migration in the caudal fin injury model. This study indicated the important roles of cordycepin in inhibiting LPS and injury-induced inflammation and preliminarily explained the role of ERK protein in this process.