Objective:To analyze the immune effect of tetanus toxoid (TT) and to provide reference for improving immunoprophylaxis strategies against tetanus.Methods:From 2019 to 2021, the TT-containing vaccine (TTCV) immunization history of patients treated for trauma in Luoshan Street Community Health Service Center of Jinjiang City were investigated. Serum tetanus antibody (TAB) levels were detected in 353 subjects (group A) 5-10 years after TTCV immunization, and the proportions of subjects with different TAB levels (<0.01 IU/ml, 0.01-0.10 IU/ml, >0.10 IU/ml) in different age groups were compared. Sixty-eight subjects (group B) aged 14-83 years with TTCV immunization history and TAB level of 0.01-0.10 IU/ml and 133 subjects (group C) aged 17-77 years without TTCV immunization history were inoculated with one dose and three doses of TT respectively, and the changes in TAB level were observed 28 d after immunization.Results:In group A, the proportions of subjects with different TAB levels in different age groups were statistically significant (χ 2=47.69, P<0.001). The proportions of subjects in which TAB levels were <0.01 IU/ml and 0.01-0.10 IU/ml increased with age. In group B, 66 out of the 68 subjects had TAB >0.10 IU/ml 28 d after one dose of TT immunization. There were statistically significant differences in the proportions of subjects whose TAB levels were 0.01-0.10 IU/ml and >0.10 IU/ml before and after TT immunization (χ 2=128.23, P<0.001). In group C, before three doses of TT immunization, 129 patients had TAB <0.01 IU/ml and four patients had TAB in the range of 0.01-0.10 IU/ml; 28 d after three doses of TT immunization, only one case had TAB in the range of 0.01-0.10 IU/ml and 132 cases had TAB >0.10 IU/ml. The proportions of group C subjects with different TAB levels before and after TT immunization were statistically significant (χ 2=262.80, P<0.001). Conclusions:Five years after TTCV immunization, the proportions of individuals with TAB <0.01 IU/ml and in the range of 0.01-0.10 IU/ml increased with age. For people without TTCV immunization history and those with decreased TAB protection after TTCV immunization, strengthening TT immunization could significantly improve the TAB protection.

To test the therapeutic effect of recombinant fusion polypeptide hEGF-AWRK6 (EK) on burn infection of model mice. EK6 was expressed and purified with Escherichia coli expression system, and the Ⅱ degree burns and Pseudomonas aeruginosa infection model mouse were established. Experiment group was treated with EK (30 mg/L), and the control group was treated with PBS, gentamicin (30 mg/L), burn ointment (10 mg/L). The wound healing rate and colony count were calculated. Wound and surrounding skin were taken for HE staining and collagen western-blot analysis, and the wound pathological changes were observed after 10 days of drug delivery. The results showed that fusion peptide EK was successfully expressed and purified with significant antibacterial activities against Pseudomonas aeruginosa. Compared to the control group, the colony count (CFU) of the wound surface in EK mouse had a remarkable decrease (P<0.01) and healing rate had a significant increase in group EK6 (P<0.01). Pathological analysis result showed that compared to the control group, wound dermal cells in group EK arranged regularly, had more hair growth and a faster epithelization. These results indicated that the fusion peptide EK would be a good candidate for the drug development for the treatment of burning wounds.

Objective : The purpose of this study was to clarify the regulatory effect and mechanism of Src homology-2 domain containing protein tyrosine phosphatase-2 (SHP2) on human periodontal ligament stem cell (hPDLSC) proliferation and osteogenic differentiation under inflammatory environment and to provide a new target for the treatment of periodontitis. Methods: SHP2 was knocked down in hPDLSCs, and the transfection efficiency of SHP2 was detected by RT-qPCR and Western blot. An in vitro inflammatory environment was created using tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). The effect of SHP2 knockdown on hPDLSC viability under normal and inflammatory conditions was detected by CCK-8, and the osteogenic capacity of hPDLSCs under normal and inflammatory conditions was detected by ALP staining, ALP activity, ARS staining, RT-qPCR and Western blot. The mechanism by which SHP2 knockdown affected the MAPK pathway and its downstream NF-κB pathway under inflammatory conditions was assessed by Western blot. Results: Green fluorescence was observed after transfection for 72 h, and the titer of SHP2 shRNA recombinant lentivirus was 2.9×108 TU/mL. SHP2 expression was significantly downregulated in lentivirus-transfected cells, as demonstrated by Western blot and RT-qPCR (P<0.001). SHP2 knockdown inhibited hPDLSC proliferation to a certain extent and increased the expression of early osteogenic markers under normal conditions, including increased ALP activity and increased ALP and COL-1 expression (P<0.05). However, SHP2 knockdown exerted no effect on mineralized nodule formation. In the TNF-α- and IL-1β-induced inflammatory environment, SHP2 knockdown exerted no effect on hPDLSC proliferation (P>0.05). Osteogenic markers were upregulated (P<0.05), and mineralized nodules were significantly increased (P<0.05) after SHP2 knockdown. Western blot analysis showed that p65 phosphorylation and IκB-α degradation were reduced in SHP2-knockdown hPDLSCs in the inflammatory environment. Moreover, SHP2 knockdown significantly inhibited the expression of p-p38 and p-JNK MAPK, which represent pathways upstream of the NF-κB pathway (P<0.05). Conclusion SHP2 knockdown did not affect cell viability but promoted the osteogenic potential of hPDLSCs by inhibiting the MAPK/NF-κB-mediated signaling pathway under inflammatory environment.