Pneumococcal wall teichoic acid is required for the pathogenesis of Streptococcus pneumoniae in murine models

Hongmei Xu,Libin Wang,Jian Huang,YanQing Zhang,Feng Ma,Jianmin Wang,WenChun Xu,XueMei Zhang,YiBing Yin,KaiFeng Wu 한국미생물학회 2015 The journal of microbiology Vol.53 No.2

Pneumococcal asymptomatic colonization of the respiratory tracts is a major risk for invasive pneumococcal disease. We have previously shown that pneumococcal wall teichoic acid (WTA) was involved in pneumococcal infection of sepsis and adherence to epithelial and endothelial cells. In this study, we investigated the contribution of pneumococcal WTA to bacterial colonization and dissemination in murine models. The result showed that nasopharynx colonizing D39 bacterial cells have a distinct phenotype showing an increased exposure of teichoic acids relative to medium-grown bacteria. The WTA-deficient mutants were impaired in their colonization to the nasopharynx and lungs, and led to a mild inflammation in the lungs at 36 h post-inoculation. Pretreatment of the murine nares with WTA reduced the ability of wild type D39 bacteria to colonize the nasopharynx. In addition, the WTA-deficient strain was impaired in its ability to invade the blood and brain following intranasal administration. WTA-deficient D39 strain was reduced in C3 deposition but was more susceptible to the killing by the neutrophils as compared with its parent strain. Our results also demonstrated that the WTA enhanced pneumococcal colonization and dissemination independently of the host strains. These results indicate that WTA plays an important role in pneumococcal pathogenesis, both in colonization and dissemination processes.

Serotype-Independent Protection against Pneumococcal Infections Elicited by Intranasal Immunization with Ethanol-Killed Pneumococcal Strain, SPY1

XiuYu Xu,Qun Zhang,Jiangping Meng,Yiping Wang,Jie Zheng,Kaifeng Wu,Xuemei Zhang,Yibing Yin 한국미생물학회 2014 The journal of microbiology Vol.52 No.4

The 23-valent polysaccharide vaccine and the 7-valent pneumococcalconjugate vaccine are licensed vaccines that protectagainst pneumococcal infections worldwide. However,the incidence of pneumococcal diseases remains high in lowincomecountries. Whole-cell vaccines with high safety andstrong immunogenicity may be a favorable choice. We previouslyobtained a capsule-deficient Streptococcus pneumoniaemutant named SPY1 derived from strain D39. As anattenuated live pneumococcal vaccine, intranasal immunizationwith SPY1 elicits broad serotype-independent protectionagainst pneumococcal infection. In this study, forsafety consideration, we inactivated SPY1 with 70% ethanoland intranasally immunized BALB/c mice with killed SPY1plus cholera toxin adjuvant for four times. Results showedthat intranasal immunization with inactivated SPY1 inducedstrong humoral and cellular immune responses. Intranasalimmunization with inactivated SPY1 plus cholera toxin adjuvantelicited effective serotype-independent protection againstthe colonization of pneumococcal strains 19F and 4 as well aslethal infection of pneumococcal serotypes 2, 3, 14, and 6B. The protection rates provided by inactivated SPY1 againstlethal pneumococcal infection were comparable to those ofcurrently used polysaccharide vaccines. In addition, vaccinespecificB-cell and T-cell immune responses mediated theprotection elicited by SPY1. In conclusion, the 70% ethanolinactivatedpneumococcal whole-cell vaccine SPY1 is a potentiallysafe and less complex vaccine strategy that offersbroad protection against S. pneumoniae.

SP0454, A Putative Threonine Dehydratase, Is Required For Pneumococcal Virulence In Mice

WenJuan Yan,Hong Wang,WenChun Xu,KaiFeng Wu,Run Yao,XiuYu Xu,Jie Dong,YanQing Zhang,Wen Zhong,XueMei Zhang 한국미생물학회 2012 The journal of microbiology Vol.50 No.3

Increasing pressure in antibiotic resistance and the requirement for the design of new vaccines are the objectives of clarifying the putative virulence factors in pneumococcal infection. In this study, the putative threonine dehydratase sp0454 was inactivated by erythromycin-resistance cassette replacement in Streptococcus pneumoniae CMCC 31203 strain. The sp0454 mutant was tested for cell growth, adherence, colonization, and virulence in a murine model. The Δsp0454 mutant showed decreased ability for colonization and impaired ability to adhere to A549 cells. However, the SP0454 polypeptide or its antiserum did not affect pneumococcal CMCC 31203 adhesion to A549 cells. The sp0454 deletion mutant was less virulent in a murine intranasal infection model. Real-time RT-PCR analysis revealed significant decrease of the pneumococcal surface antigen A expression in the sp0454 mutant. These results suggest that SP0454 contributes to virulence and colonization, which could be explained in part by modulating the expression of other virulence factors, such as psaA in pneumococcal infection.

Tailored therapy and long-term surveillance of malignant germ cell tumors in the female genital system: 10-year experience

Qianying Zhao,Jiaxin Yang,Dongyan Cao,Jiangna Han,Kaifeng Xu,Yongjian Liu,Keng Shen 대한부인종양학회 2016 Journal of Gynecologic Oncology Vol.27 No.3

Objective: To explore the appropriate treatment of malignant germ cell tumor (MGCT) in thefemale genital system, and to analyze the factors influencing both therapeutic response andsurvival outcome. Methods: A cohort of 230-Chinese women diagnosed with MGCT of the genital systemwas retrospectively reviewed and prospectively followed. The demographic and pathologicalfeatures, extent of disease and surgery, treatment efficiency, recurrence and survival wereanalyzed. Results: MGCTs from different genital origins shared a similar therapeutic strategy andresponse, except that all eight vaginal cases were infantile yolk sac tumors. The patients’ curerate following the initial treatment, 5-year overall survival and disease-free survival (DFS)were 85.02%, 95.00%, and 86.00%, respectively. Although more extensive excision couldenhance the remission rate; it did not improve the patients’ survival. Instead, the level of themedical institution, extent of surgery and disease were independent prognostic factors forrelapse (p<0.05). Approximately 20% of patients had recurrent or refractory disease, morethan half of whom were in remission following secondary cytoreductive surgery with salvagechemotherapy. Conclusion: Fertility-sparing surgery with or without standardized PEB/PVB (cisplatin,etoposide/vincristine, and bleomycin) chemotherapy is applicable for female MGCTsof different origins. Comprehensive staging is not required; nor is excessive debulkingsuggested. Appropriate cytoreduction by surgery and antineoplastic medicine at anexperienced medical institution can bring about an excellent prognosis for these patients.

Preparation of Non-Planar-Ring Epoxy Thermosets Combining Ultra-Strong Shape Memory Effects and High Performance

Qiong Li,Songqi Ma,Jingjing Wei,Sheng Wang,Xiwei Xu,Kaifeng Huang,Binbo Wang,Wangchao Yuan,Jin Zhu 한국고분자학회 2020 Macromolecular Research Vol.28 No.5

Non-planar-ring epoxies together with non-planar-ring hardeners could achieve thermosets combining ultra-high shape recovery speed and excellent thermal properties. High shape recovery speed reflected high efficiency, and could decrease the energy consumption and the harmful effect of external stimuli on the materials, while it often conflicts with the thermal properties of shape memory polymers. In this paper, for the first time, epoxy resins with the super-short shape recovery time within 3 s were developed from non-planar-ring epoxies and hardeners, and their glass transition temperature (T g) were ~127 °C much higher than their benzene ring analogues. The effects of non-planar-ring structures of the epoxies and hardeners on the curing behavior, thermal properties as well as the shape memory properties of the thermosets were systematically investigated; the structure-property relationships were disclosed with the help of computational simulation of structure parameters and ESP maps. The faster shape recovery speed of the non-planar-ring epoxy thermosets is from their higher molecular mobility contributed by the conformational transition of non-planar-rings as well as their higher recovery force compared with benzene ring analogs. Their higher T gs are from the steric hindrance by the larger molecular volume of the non-planar-rings than benzene ring. This work will provide an effective method to produce shape memory polymers with excellent shape memory effects and high performance.