Biomedical subjects

Daoyin Zhu

Publications and source records attributed to Daoyin Zhu.

3 recordsLinked to original sources

PubMed2005

Therapeutic effects of Ag85B and MPT64 DNA vaccines in a murine model of Mycobacterium tuberculosis infection.

A new improved therapeutic strategy for tuberculosis is urgently needed. In our previous work DNA vaccines encoding secreted proteins Ag85B and MPT64 have been reported to protect mice from following H37Rv challenge by prompting the Th1 response and we consider whether these vaccines have the therapeutic effect through the same mechanism. In the present study these two DNA vaccines were tested in a mouse tuberculosis model to confirm their immunotherapeutic effect. C57BL/6 mice infected with Mycobacterium tuberculosis were treated with pCDNA3.1, pcD85B, pcDMPT64, pcD85B plus pcDMPT64, respectively. The numbers of viable bacteria in lung and spleen were counted as log(10)CFU/g. The level of IFN-gamma, IL-4 and TNF-alpha released by spleen lymphocytes stimulated with PPD was detected with ELISA. Lungs and spleens were harvested for pathological analysis. The pcD85B group reduced the pulmonary and splenic bacterial loads of 1.2 and 0.7 logs, respectively compared with that of control mice, but the difference between pcDMPT64 group and control mice was not significant. Vaccination with pcD85B induced high level of IFN-gamma and TNF-alpha. No change of IL-4 level was found in all groups. The pathological change in lung in pcD85B group was slight, alveolar wall structure is clear and the lesions are constrained, while that in control group was extensive, alveoli and interalveolar septae are effaced. And there was no special change in spleen in all groups. In conclusion, Ag85B DNA vaccination has immunotherapeutic effects, and the effects may be associated with a switch to Th1 response and prompting production of cytokine TNF-alpha and INF-gamma synchronously. Therefore, MPT64 DNA vaccination has no immunotherapeutic effect on mice tuberculosis. Rather, the effects may be associated with its disability in switching improper immune status and with recalling a strong and early specific memory immune response against tuberculosis.

Acyltransferases↗

PubMed2005

DNAzymes targeting the icl gene inhibit ICL expression and decrease Mycobacterium tuberculosis survival in macrophages.

Latent infection with Mycobacterium tuberculosis presents a big obstacle for tuberculosis therapy. In this study, we investigated the effects of sequence-specific DNAzymes targeting the mRNA of isocitrate lyase (ICL), an enzyme playing a pivotal role in the metabolism of M. tuberculosis in the latent state, on the expression of ICL and survival of M. tuberculosis. In vitro studies showed that four of five designed DNAzymes, DZ1, DZ3, DZ4, and DZ5 could cleave icl mRNA efficiently and specifically. Treatment of virulent M. tuberculosis with 5microM DZ4 plus a subinhibitory concentration of isoniazid (INH) decreased ICL expression and the survival of M. tuberculosis in macrophages but had no obvious influence on the growth of M. tuberculosis in vitro. This study demonstrates that using INH to soften the cell wall of M. tuberculosis and help the entry of biomolecules is an efficient method of improving the uptake of DNAzymes. Silencing the icl gene by DNAzyme is a promising method to combat latent infection of tuberculosis.

Antitubercular Agents↗

PubMed2002

[A study on ways of intrauterine infection of chlamydia trachomatis].

OBJECTIVE: To study the route of intrauterine infection of chlamydia trachomatis (CT). METHODS: Seven hundred and seventy-two cervical samples from in women and 105 matched maternal-labom neonatal samples composed of cervical samples, cord blood, amniotic fluid, conjunctival and nasopharyngeal samples of neonate were detected by PCR-SSCP and DNA sequencing technique. RESULTS: CT were detected in 87 of 772 (11.3%) cervical samples. In the 81 matched maternal-infant samples from pregnant women with cervical CT-positive, CT were not detected in all of the cord blood samples. In the 30 CT-positive neonatal samples, 26 were from cases of vaginal delivery and 4 from cases of caesarean section. Statistical analysis showed a significant difference between the groups of caesarean section and the vaginal delivery (P < 0.01). Four of 11 amniotic fluid samples with CT-positive were obtained during caesarean section in which 3 were without premature rupture of membranes (PROM), SSCP patients were same between maternal samples and matched neonatal samples. The sequences of amplified DNA fragments also showed the same results between maternal and match neonatal samples. No samples were found CT-positive in 24 matched maternal-infant samples from cervical CT-negative women. CONCLUSIONS: An ascending transmission from cervix to amniotic cavity was the major route for CT intrauterine infection. Transplacental passage of chlamydial infection was not confirmed. Rates of vertical transmission were significantly lower in caesarean section group than that of vaginal delivery group with maternal cervical chlamydial positive.

Amnion↗