Expression, purification, and characterization of pneumococcal PsaA-PspA fusion protein

Guo, Xiaonan; Sun, Qing; Xi, Hualong; Zhang, Yue; Guo, Mengze; Zhang, Chenxing; Zhu, Shidong; Gu, Tiejun; Kong, Wei; Wu, Yongge

doi:10.1016/j.pep.2020.105782

Cited by 2 publications

(3 citation statements)

References 37 publications

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“…14,15 In this study, we selected the full-length PiuA sequence without the signal peptide and transmembrane structure domain and connected it with PlyD4 through a flexible linker to form the fusion protein PiuA-PlyD4 that consists of two antigenic structures, aiming to obtain a fusion protein vaccine with better protective efficacy. 14,16 Our study provides an important basis for the development of universal protein vaccines against S. pneumoniae infection.…”

Section: Introductionmentioning

confidence: 96%

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae

Miao,

Cui,

et al. 2023

DDDT

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Purpose This study was designed to evaluate the immune protective efficacy of the novel Streptococcus pneumoniae (S. pneumoniae) protein vaccine PiuA-PlyD4 through immunoinformatics prediction and in vitro and in vivo experiments. Methods In this study, we conducted immunoinformatics prediction and protection analysis on the fusion protein PiuA-PlyD4. The epitope composition of the vaccine was analyzed based on the prediction of B-cell and helper T-cell epitopes. Meanwhile, the molecular docking of PiuA and TLR2/4 was simulated. After immunizing C57BL/6 mice with the prepared vaccine, the biological safety, immunogenicity and conservation were evaluated. By constructing different infection models and from the aspects of adhesion inhibition and cytokines, the protective effect of the fusion protein vaccine PiuA-PlyD4 on S. pneumoniae infection was explored. Results PiuA-PlyD4 has abundant B-cell and helper T-cell epitopes and shows a high antigenicity score and structural stability. Molecular docking analysis suggested the potential interaction between PiuA and TLR2/4. The specific antibody titer of fusion protein antiserum was as high as (7.81±2.32) ×10 5 . The protective effect of the immunized mice on nasal and lung colonization was significantly better than that of the control group, and the survival rate against S. pneumoniae infection of serotype 3 reached 50%. Cytokine detection showed that the humoral immune response, Th1, Th2 and Th17 cellular immune pathways were all involved in the process. Conclusion The study indicates that PiuA-PlyD4, whether the results are predicted by immunoinformatics or experimentally validated in vivo and in vitro, has good immunogenicity and immunoreactivity and can provide effective protection against S. pneumoniae infection. Therefore, it can be considered a promising prophylactic vaccine candidate for S. pneumoniae .

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Section: Introductionmentioning

confidence: 96%

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae

Miao,

Cui,

et al. 2023

DDDT

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“…As a gram-positive bacterial pathogen, Streptococcus pneumoniae can cause invasive pneumonia, meningitis, otitis media, bacteremia (1), and acute respiratory distress requiring mechanical ventilation (2). Streptococcus pneumoniae is a leading cause of pneumonia, mostly in children less than five years and elderly people (3).…”

Section: Introductionmentioning

confidence: 99%

“…Pneumonia is fatal in HIVinfected patients due to rampant and systemic inflammation and failure to control microbial infection (4), and communityacquired pneumonia is characterized as an acute inflammation of the lung associated with the activation of macrophages and neutrophils (5). The secretion of proinflammatory cytokines such as interleukin-8 (IL-8) and IL-6 by respiratory epithelial cells induced by the infection of respiratory bacteria, contributes to the onset of pneumonia (1). Macrophages are a class of leukocytes with antigen presentation ability which actively participate in tissue remodeling, phagocytosis, and clearance of foreign substances and cell debris (6).…”

Section: Introductionmentioning

confidence: 99%

G9a promotes inflammation in Streptococcus pneumoniae induced pneumonia mice by stimulating M1 macrophage polarization and H3K9me2 methylation in FOXP1 promoter region

Li¹,

Li²,

Zhang³

et al. 2022

Ann Transl Med

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Background: Streptococcus pneumoniae has become a leading cause of pneumonia in recent years. Here, we investigated the mechanism of histone methylase G9a in Streptococcus pneumoniae-induced pneumonia (Spn).Methods: G9a expression in Spn mouse tissue was measured. G9a lentivirus interference vector was injected into Spn mice to evaluate the wet and dry weight of the right upper lobe and the total lung water content (TLW) and wet/dry ratio (W/D). The number of neutrophils, macrophages, and lymphocytes in bronchoalveolar lavage fluid (BALF) was detected, and the levels of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and IL-10 in BALF were assessed. The expressions of M1 and M2 macrophage markers were also detected. The enrichment of histone 3 lysine 9 dimethylation (H3K9me2) in the Forkhead Box P1 (FOXP1) promoter was detected by chromatin immunoprecipitation (ChIP) assay, and the transcription level of FOXP1 was detected. Mouse macrophage RAW264.7 was induced by lipopolysaccharide (LPS) following G9a interference.Results: G9a in the lung tissue of Spn mice was increased. After G9a knockdown, the mouse weight increased, the infiltration of inflammatory cells was decreased, levels of pro-inflammatory cytokines in BALF were decreased, CD86 and inducible nitric oxide synthase (iNOS) were decreased, and CD206 and arginase-1 (Arg-1) were elevated. In LPS-induced RAW264.7, G9a inhibited macrophage polarization to M1 and promoted macrophage polarization to M2. G9a promoted H3K9me2 methylation in the FOXP1 promoter region and inhibited its transcription, while FOXP1 downregulation reversed the inhibition of G9a knockdown on macrophage polarization to M1 and the inflammatory effect on Spn mice.Conclusions: G9a promotes M1 polarization of macrophages by promoting H3K9me2 methylation in the FOXP1 promoter region, promoting an inflammatory response in Spn mice.

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Expression, purification, and characterization of pneumococcal PsaA-PspA fusion protein

Cited by 2 publications

References 37 publications

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae

Immunoinformatics Prediction and Protective Efficacy of Vaccine Candidate PiuA-PlyD4 Against Streptococcus Pneumoniae

G9a promotes inflammation in Streptococcus pneumoniae induced pneumonia mice by stimulating M1 macrophage polarization and H3K9me2 methylation in FOXP1 promoter region

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