Xiao Zha

Controlled release of PEI/DNA complexes from mannose-bearing chitosan microspheres as a potent delivery system to enhance immune response to HBV DNA vaccine

Abstract A novel approach involving the preparation of mannose-bearing chitosan microspheres with entrapping complexes of HBV DNA and PEI was developed to improve the delivery of DNA into antigen-presenting cells (APCs) after intramuscular (i.m.) injection. Compared with the traditional chitosan microspheres, the microspheres could quickly release intact and penetrative PEI/DNA complexes. Whats more, chitosan was modified with mannose to target the primary APCs such as dendritic cells (DCs) owing to the high density of mannose receptors expressing on the surface of immature DCs. After i.m. immunization, the microspheres induced significantly enhanced serum antibody and cytotoxic T lymphocyte (CTL) responses in comparison to naked DNA.

Profile of physical status and gene variation of human papillomavirus 58 genome in cervical cancer

Epidemiological studies have shown that human papillomavirus 58 (HPV 58) is found at a relatively high frequency in east Asia and some regions of Central and South America. To investigate the physical status of HPV 58 and analyse sequence variations of HPV 58 in cervical cancer patients, the HPV 58 genome in 37 HPV 58-positive cervical cancer specimens collected from China were investigated by a mapping analysis based on nested PCR and nucleotide sequencing. A pure integrated genome was found in 78.4 % (29/37) of specimens, which is much higher than that found in previous studies. Multiple disruptions were first found among the integrated HPV 58 genomes in 51.7 % (15/29) of specimens. Among the 7824 bp of the HPV 58 genome, 119 (1.52 %) nucleotide positions were found to be variable, and 45 of them lead to amino acid changes. Phylogenetic analyses, based on partial L1 sequences of 14 variants isolated in previous studies and this study, show that two main groups were observed in HPV 58 variants, the prototype or prototype-like group and the non-prototype-like group.

Evaluation of high-risk Human papillomaviruses type distribution in cervical cancer in Sichuan province of China

BackgroundInfection with high-risk human papillomavirus is an important factor associated with cervical cancer, and the distribution of HPV types varies greatly worldwide. Determination of type-specific HPV prevalence constitutes an important step towards the development of vaccines for the prevention of cervical cancer.MethodsThe human papillomavirus (HPV) genotypes in 190 cervical cancer specimens taken from the Sichuan province, the most populous province of Southwest China, were detected by a combination of MY09/11 consensus primers PCR (MY09/11 PCR), type-specific primers one-step PCR (One-step TS PCR) and E6/E7 gene type-specific primers nested PCR (Nested TS PCR). The prevalence and distribution of HPV in patients with cervical cancer, especially for HPV types 16, 18, 52, 58 and 59, suspected to be most common in certain parts of China, was investigated.ResultsThe HPV infection rates detected by MY09/11 PCR, One-step TS PCR and Nested TS PCR were 159 (83.7%), 145 (76.3%) and 172 (90.5%), respectively. The overall HPV prevalence was 93.2% (177/190). The positive specimens for HPV16, 18, 52, 58 and 59 detected by One-step TS-PCR were 111 (58.4%), 14 (7.4%), 6 (3.2%), 13 (6.8%) and 4 (2.1%), respectively. By Nested TS-PCR analysis, the detection rates of HPV16, 52, 58 and 59 were increased to 140 (73.7%), 30 (15.8%), 37 (19.5%) and 25 (13.2%), while only 4 (2.1%) additional specimens were found to be infected with HPV18.ConclusionOur data demonstrate that, besides HPV 16, which was found to be the most prevalent type, HPV types 58, 52 and 59 are more prevalent than HPV18 in women with cervical cancer in the Sichuan area of China.

Enhance immune response to DNA vaccine based on a novel multicomponent supramolecular assembly

Abstract DNA vaccination has tremendous potential for treating or preventing numerous diseases for which traditional vaccines are ineffective but the technique can be limited by low immunogenicity. Current synthetic DNA delivery systems are versatile and safe, but substantially less efficient than viruses. Here, a novel multicomponent supramolecular system involving the preparation of mannose-bearing chitosan oligomers microspheres with entrapping complexes of DNA vaccine and polyethylenimine was developed to mimic many of the beneficial properties of the viruses. After delivery by intramuscular immunization in BALB/c mice, the microspheres induced an enhanced serum antibody responses two orders of magnitude greater than naked DNA vaccine. Additionally, in contrast to naked DNA, the microspheres induced potent cytotoxic T lymphocyte responses at a low dose. Consequently, formulation of DNA vaccines into multicomponent vectors is a powerful means of increasing vaccine potency.

Distribution of human papillomavirus genotypes in archival cervical lesions in Eastern Inner Mongolian autonomous region, China.

Introduction: Human papillomavirus (HPV) is the main etiologic factor for cervical cancer (CC). To investigate the prevalence of HPV types in archival CC and its precursors collected form Tongliao area, which is located in the east of Inner Mongolian autonomous region, China, and compare the genotype distribution of HPV in cervical lesions between Han Chinese and Mongolian. Methods: The infections of HPV in a total of 175 cases of formalin-fixed, paraffin-embedded samples, including 71 low-grade squamous intraepithelial lesions (LSIL), 27 high-grade squamous intraepithelial lesions (HSIL), and 77 CC were detected by the combination of consensus primers nested polymerase chain reaction (PCR) and type-specific primers nested PCR. Results: Overall, HPV prevalence was 93.5% in CC, 92.6% in HSIL, and 63.4% in LSIL. Human papillomavirus 16 was the most predominant HPV type in all cervical lesions, detected in 83.1% of CC, 77.8% of HSIL, and 33.8% of LSIL. Human papillomavirus 45 was the second most predominant HPV type in CC (16.9%) and HSIL (11.1%). Human papillomavirus 33 was the second most predominant HPV type in LSIL (8.5%). Human papillomavirus 18, equal with HPV 45, was the second most common type in Mongolian CC (15.6%), whereas in Han Chinese specimens, no HPV 18 was found. Conclusions: The prevalence of HPV 45 in CC and HSIL in Tongliao area were relatively higher than other regions of China. Comparing the distribution of HPV types in Han Chinese and Mongolian, the prevalence of HPV 18 in CC from Mongolian was significantly higher than that in Han Chinese.

Detection of human papillomavirus genotypes associated with mucopurulent cervicitis and cervical cancer in Changchun, China

To determine the prevalence and genotype distribution of human papillomavirus (HPV) infection among Chinese patients with mucopurulent cervicitis (MPC) or cervical cancer (CC).