Study on characteristics of cellular-mediated immune responses of novel H1N1 influenza A patients with pneumonia / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To investigate the phenotype, frequency and function of CD4+ T cell subsets and the relevant cytokines, as well as the relationship between these cells and appearance of pneumonia of novel (H1N1) influenza A patients.</p><p><b>METHODS</b>68 healthy people, 53 confirmed novel A(H1N1) influenza patients without pneumonia and 16 confirmed severe novel A (H1N1) influenza patients with pneumonia were enrolled in this study. Viral load in nasopharyngeal swabs specimens was measured by real time PCR assay. The phenotype and percentage of CD4+ T cell subsets including Th1, Th2, Th17, and Treg cells were measured by Flow cytometry analysis. The relevant cytokines in plasma including TGF-beta, IL-6 and IFN-gamma were measured by ELISA. Data was analyzed by one way ANOVA.</p><p><b>RESULTS</b>It was found that peak viral load and viral shedding period of severe patients with pneumonia was significantly increased compared with mild patients without pneumonia (P < 0.05). The percentage of Th17 cells of severe patients with pneumonia was significantly diminished compared to that of healthy subjects and mild patients without pneumonia (P < 0.05). However, Th1, Th2, Treg cells frequencies had no significant differences (P > 0.05) among these three groups. The level of TGF-beta in plasma for the severe patients with pneumonia was also significantly decreased compared to that of healthy subject and mild patients without pneumonia (P < 0.05). The viral shedding period inversely correlated with the frequency of Th17 cells (r = - 0.38, P < 0.05).</p><p><b>CONCLUSION</b>H1N1 influenza A virus can inhibit Th17 cells to differentiate, particularly more extent in patients with pneumonia. Impaired Th17 cells may correlate with viral clearance and pneumonia of novel H1N1 influenza A patients.</p>

Expression of a single-chain trimer of MHC restricted HBsAg CTL epitope using adenovirus vector containing GFP-report gene / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To generate a recombinant Adenovirus encoding a GFP (green fluorescent protein)-report gene and a single-chain trimer of MHC restricted HBsAg CTL epitope.</p><p><b>METHODS</b>An oligonucleotide encoding H-2L(d) restricted HBsAg CTL epitope was synthesized and fused with H-2L(d) DNA molecule to construct the eukaryotic expression vector carrying the HBsAg-SCT gene. The HBsAg-SCT gene was subcloned into a GFP adenovirus expression vector,which was transfected into Ad293 cells for packaging and amplification of recombinant adenovirus encoding HBsAg-SCT.</p><p><b>RESULTS</b>HBsAg-SCT has been cloned into an adenovirus vector encoding GFP report gene successfully as confirmed by double enzyme digestion and direct sequencing. HBsAg-SCT was expressed by infected Ad293 cells demonstrated by western blot assay.</p><p><b>CONCLUSION</b>A recombinant adenovirus expressing HBsAg-SCT and green fluorescent protein report gene has been generated.</p>

Study of the clinical and laboratory features of hand-foot-mouth disease / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the clinical and laboratory features of the mild and severe hand-foot-mouth diseases (HFMD) in Shenzhen in 2008.</p><p><b>METHODS</b>145 cases were observed in East-Lake Hospital and Shenzhen Children's Hospital. Of the 145 cases, 124 mild cases and 21 severe cases were involved.All the clinical data and laboratory findings were collected and summarized. After collection of the acute and convalescent consecutive stools and peripheral bloods from the patients with HFMDI, EV71 genes were amplified from these samples by RT-PCR. Enterovirus 71 were cultured and isolated using Vero cell line and R&D cell line.</p><p><b>RESULTS</b>The WBC counts and blood glucose levels of the severe cases were significantly elevated, but the ages of the severe ones significantly decreased compared with those of the mild cases (P < 0.05). EV71 genes could be detected by RT-PCR with 35% positive rate in mild cases and 67% in severe cases. The EV71 gene detection rate of the severe cases was significantly increased in contrast to that of the mild ones. The EV71 were isolated and cultured from the stools of 9 patients, one specimens from the dead's stool. Two severe cases died of neurogenic pulmonary edema and brain-stem encephalitis.</p><p><b>CONCLUSIONS</b>EV71 mainly contributes to HFMD and is responsible for death of some severe cases. High fever, less rash, elevated white blood cell counts and blood glucose concentrations as well as age less than 4 years old should be used for prediction of severe cases.</p>