Objective To research Dengue virus type 2 (DENV-2) to human umbilical vein endothelial cells (HUVEC) permeability. Methods The titration of DENV-2 was detected and HUVEC infection DENV-2 layer of cells. At different time points after infection (30 min, 1 h, 3 h, 6 h, 12 h, 30 h,36 h, 24 h, 42 h, 48 h,72 h), the permeability in HUVEC were detected after Dengue virus infection. The virus load in HUVEC was detected by quantitative real-time PCR. And ultrastructure in HUVEC was observed by electron microscope. Results The permeability in HUVEC was changed after Dengue virus infection by time lasting. The most permeability in HUVEC was changed after Dengue virus infection at 30 min and 42 h. And at the same time the virus load were most value in all of time. The results of the cell membrane were changed by electron microscope. The deciduous cell microvillus and dissd endochylema were founded. And some of nuclear membrane blank was wided by Dengue virus. Even the leakage was founded in cell nucleus. The other change included that disappearance mitochondrial and vacuolization crista, elder pith change mitochondria. In addition, the complete of cell membrane were dissolved. Conclusion The permeability of HUVEC was changed by DENV-2. To explore the pathogenesis of Dengue virus provide certain theoretical basis.

Objective To study the relationships between neutralizing antibody response against heterologous virus and disease progression in Chinese HIV-1 B'/C infected individuals. Methods Plasmas from HIV-1-infected individuals, grouped as HIV chronically infected or AIDS according to CD4+ count and clinical symptom, were tested for neutralizing activity against the three HIV-1 isolates with very low homology in vitro. Six two-fold dilutions of each plasma sample (from 1/10 to 1/320) were tested against each virus from the panel. Giving a 50% reduction in p24Ag compared with normal human plasma control wells was defined as positive. The breadth of the cross-neutralizing response was defined based on the number of viruses that were effectively neutralized by any given patient-derived plasma sample. The magnitude of the crossneutralizing response was defined based on the average neutralizing titer against all heterologous viruses. Resuits We found that there revealed a significant difference between HIV chronically infected and AIDS group in the breaths and magnitudes of neutralizing heterologous virus. There was higher prevalence for the frequency of neutralizing heterologous virus in HIV chronically infected than AIDS. The results showed that there was positive correlation between the breadths and magnitudes of neutralizing response against heterologous virus and the plasma HIV RNA level in HIV chronically infected group, while not in AIDS group. There was no association between the breadth of the neutralizing responses against heterologous virus and CD4 T cell counts. Conclusion The capacity of neutralizing antibodies against heterologous virus varied among different disease stage. There were higher titers of neutralizing antibodies in HIV chronically infected than AIDS group. The loss of neutralizing antibodies in plasma from AIDS group appears to be associated with a narrowing of the antibody response during disease progression. These suggest that the presence of neutralizing antibodies against hetreologous virus was associated with disease progression.

Objective:To study the relationships between neutralizing antibody response against autologous virus and disease progression of HIV-1 B'/C infected individuals in China.Methods:Twenty-four primary HIV-1 isolates were incubated with autologous plasma collected either freshly or at approximately six months intervals thereafter.Normal human peripheral blood mononuclear cells were incubated with the virus-serum mixtures for 7 days and then the production of p24 antigen was measured.The neutralizing titer of a particular plasma and virus was defined as the reciprocal of the highest dilution giving a 50% reduction in p24 Ag compared with NHP control wells.More than 1∶8 were considered significant and were scored as positive.Results:In neutralizing antibody(Nabs) response against contemporaneous virus,Nabs were produced in all slow progressors(SP) individuals,while only four in 21 of HIV group had.There was statistically significance of the neutralizing antibody titers between SP and HIV.When plasma samples of six months later were tested for their ability to neutralize autologous virus,all of SPs had higher neutralizing antibody titers and the titers of neutralizing antibody in HIV group had increased in different rate.Among the twenty-one individuals of HIV group,12 of these individuals had neutralizing antibody response against autologous virus and other 9 of these individuals had not.NAb titers of SP in six months later plasma were higher than those of HIV.There was a negative correlation between the generation of the neutralizing titer against autologous virus and the plasma HIV RNA level in HIV-1 B'/C infected individuals(including SP,HIV).Conclusion:Neutralizing antibody against autologous viruses in HIV-1 B'/C infected SP is higher than those of HIV group,suggesting that neutralizing antibodies play a vital role in delaying disease progression in these individuals.