Effects of short-term treatment of dexamethasone on balance of natural regulatory and type Ⅰ regulatory T cells / 中国免疫学杂志

Objective:To investigate the impact of dexamethasone on the balance of natural regulatory T cells(nTreg) and typeⅠ regulatory T cell(Tr1) in vitro.Methods:Peripheral blood lymphocytes(PBMCs) recruited from healthy donor,divided into dexam-ethasone stimulus group and negative control group.After 3 days treatment,cells were stained.The expression of CD25,CD127, Lymphocyte-activation 3 (LAG-3) and Forkhead box P3 (Foxp3) and frequency of Treg and Tr1 were analyzed by flow cytometry.Results:Compared to the control group,after stimulation with dexamethasone for 3 days,the percentage of CD4+T cells increased in a dose-dependent manner.The expression of CD25 and Foxp3 in CD4+T cells decreased significantly (P=0.006, P<0.000 1),while CD127 and LAG-3 expression increased significantly in CD4+T cells (P<0.000 1,P=0.011).Dexamethasone treatment significantly enhance the frequency of Tr1(P=0.051),reduce the frequency of Treg (P<0.001),and the ratio of Tr1/Treg also increased(P=0.044).Conclusion:Short-term treatment with dexamethasone in vitro change the balance of natural regulatory and type Ⅰ regulatory T cells.

Analysis of human metapneumovirus genotype in Hunan, China and its attachment protein G sequence character / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To understand the genotypes of human metapneumovirus (hMPV) and the genetic character of hMPV attachment protein G sequence in Hunan, China.</p><p><b>METHODS</b>232 nasopharyngeal aspirates (NPA) samples from hospitalized children with acute respiratory infections were collected from Hunan, China in 2005. HMPV was detected. The full length of G glycoprotein genes were amplified and sequenced. Bioinformatics soft-wares were employed to analyze the sequences.</p><p><b>RESULTS</b>17/232 (7.3%) were showed hMPV positive. And co-infection rate with other viruses is 35%. The diagnoses of these hMPV positive cases are pneumonia, bronchiolitis and bronchopneumonia. Phylogenetic analysis for G genes from 13 hMPVs revealed the existence of four major subgroups: A1, A2, B1, B2 in Hunan, China in 2005. There are four types of sequence lengths of hMPV G glycoprotein, which are 711, 675, 660, 696nt. It is different in potential N-linked glycosylation sites and number of cysteine residues among these hMPVs of Hunan, China and Beijing, China. Also it is different from those in Japan and North America.</p><p><b>CONCLUSION</b>The investigation of hMPV from Hunan, China in 2005 revealed the high speed of genetic variation and the marked character of geographic epidemic differences.</p>

Clinical characteristics of bocavirus infection among children / 中华实验和临床病毒学杂志

<p><b>OBJECTIVE</b>To study the clinical characteristics of human bocavirus (HBoV) among children and to understand the association of HBoV with human diseases.</p><p><b>METHOD</b>Totally 148 nasopharyngeal aspirate (NPA) samples were collect from hospitalized children with acute respiratory infection during Oct. 2005 to Feb. 2006. Two serum samples were obtained from HBoV positive patients. PCR was used to assay all these samples and PCR products were sequenced.</p><p><b>RESULT</b>HBoV was positive in 11 of 148 NPA samples. The positive rate was 7.4 percent. The serum samples of HBoV infected patients showed that serum contained HBoV by PCR assay. All these HBoV positive patients had the clinical symptoms of bronchitis, bronchopneumonia and pneumonia. Some patients had diarrhea.</p><p><b>CONCLUSION</b>All patients infected with HBoV had upper and lower respiratory tract infections. HBoV is a probable important pathogen of upper and lower respiratory tract infection. The HBoV could cause viremia. In addition, some HBoV patients had diarrhea. HBoV infection probably could also result in intestinal disease and other related symptoms.</p>

Genome cloning and phylogenetic analysis of human bocavirus capsid gene / 病毒学报

The full-length genome of one human bocavirus (HBoV) and the VP1 sequences of nine HBoV were amplified from patients' samples by PCR, cloned into pGEM-T vector separately, and sequenced. In this study, the one full length gemome and nine VP1 sequences of HBoV were aligened with 14 sequences of Parvoviruses which were canonical exemplars in Parvovirinae. Phylogenetic analysis showed that HBoV capsid sequences positioned closely to B19 parvovirus, although they positioned far in phylogenetic tree based on full length genome. Many similarities were found between HBoV and B19 in capsid by alignment on secondary structural elements. Because both B19 and HBoV are the only Parvoviruses that infect mankind, so study on HBoV may be used for reference to B19 which had been studied for about 30 years. By analysis of mutational sites, HBoV capsid protein showed a highly conserved secondary structural elements, but highly active in VP1-U, leading end of VP2 and insertions between the strands of the betaG-H. This cued that HBoV inclined to immune evasion and infectant adaptive faculty.