HIV-1 infection up-regulating expression of interferon-stimulated gene 15 in cell lines / 病毒学报

To investigate whether HIV-1 infection affects expression of interferon-stimulated gene 15 (ISG15) and determine the antiviral effect of ISG15 in vitro, ISG15 expression at transcription and protein level and supernatant p24 of HIV-1 was detected in various HIV-1 infected or transfected cell lines, respec tively. HIV-1 molecular clone pNL4-3 was used to transfect 293T, TZM-bl and HeLa cells while HIV-1 pseudo-typed virus was used to infect Jurkat, MT-1 and THP-1 cells. After twenty-four hours post infection or transfection, cells were harvested for extraction of total RNAs and subsequently used in real time PCR for quantification of ISG15 transcriptional expression. After forty-eight hours post infection or transfection, cells were harvested for extraction of total proteins to detect ISG15 protein expression. A significant up-regulation of ISG15 at transcription level was observed in HIV-1 infected or transfected cell lines, particulaly in THP-1 and TZM-bl cells. Up-regulation of ISG15 protein was observed only in TZM-bl cell. Cotransfection of ISG15 and HIV-1 indicated that ISG15 inhibited production of HIV-1 progeny virus in a dose and time depend manner in 293T cell but not TZM-bl cell. These results revealed upregulating ISG15 expression in transcriptional level and potential antagonistic mechanism against ISG15 by HIV-1 infection, simultanelusly.

Immunization with HBsAg-Fc fusion protein induces a predominant production of Th1 cytokines and reduces HBsAg level in transgenic mice / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Fc receptor associated pathway might improve the immune responses against hepatitis B virus (HBV) as previously described by us. In addition, the Flt3 ligand (FL) has been reported to potentiate antigen presenting cells in vivo and may act as a potential adjuvant to boost antigen-specific immune responses. In this study, the immune efficacies of a set of fusion proteins of HBsAg and Fc and/or FL were evaluated in HBsAg transgenic mice.</p><p><b>METHODS</b>The fusion proteins composed of HBsAg and the Fc domain of murine IgG1 (HBsAg-Fc) and/or the Flt3 ligand, and yeast-derived recombinant HBsAg were used as immunogen to immunize HBsAg transgenic mice, respectively. Serum and liver HBsAg levels, serum anti-HBsAg and cytokine profile, and the activities of alanine aminotransferase (ALT)/AST were investigated after immunization.</p><p><b>RESULTS</b>After six injections, the most pronounced decrease in serum and liver HBsAg levels was observed in the HBsAg-Fc immunized group. In addition, serum Th1 cytokines and ALT/AST activities were highest in this group, indicating an effective induction of a favorable cellular immune response. Interestingly, the fusion protein containing HBsAg-Fc and the Flt3 ligand stimulated an alternative Th1-type immune response featured with high level productions of tumor necrosis factor α (TNF-α) and monocyte chemoabstractant protein 1 (MCP-1), causing a more severe cytotoxicity in hepatocytes while showed less effective in reducing serum HBsAg level.</p><p><b>CONCLUSION</b>HBsAg-Fc is effective in eliciting both the humoral and cellular immune responses against HBsAg in HBsAg transgenic mice, which makes it a potential immunogen for the immunotherapy of chronic hepatitis B.</p>

Development and identification of polyclonal antibodies against HIV-1 Vpr-derived polypeptides / 病毒学报

To develop polyclonal antibodies against predicted B cell epitopes in HIV-1 accessory protein Vpr, the prepared consensus Vpr amino acid sequence was used to predict potential B cell epitopes by online softwares (ABCpred and Bcepred), the synthesized polypeptides of B-cell epitopes were subsequently conjugated with keyhole limpet hemocyanin (KLH) and then used to immunize rabbits. The antibody titers were determined by ELISA, and antibody specifity was analyzed by Western-Blotting and immunoprecipitation, respectively. Amino acid residues 3-19 (N) and 82-95 (C) of Vpr were predicted as the potential B cell epitopes. After inoculation of the conjugation of synthesized peptide to KLH, the antibody titers in rabbit sera against N and C peptides reached more than 1:100000 by ELISA. Western-Blotting analysis showed that the polyclonal antibodies reacted with both wild Vpr and fusion protein of GFP with Vpr, no matter Vpr was derived from HIV-1 B subtype or CRF07_BC recombinant form; Immunoprecipitation analysis showed similar reactions to Western-Blotting results. Two B cell epitopes of Vpr were successfully predicted by Bio-informatics methods and polyclonal antibodies against those peptides could be successfully prepared.

HIV-1 infection affects the expression of host cell factor TSG101 and Alix / 病毒学报

To investigate the effects of HIV-1 infection on the expression of host factors TSG101 (Tumor Susceptibility Gene 101) and Alix (ALG-2-interacting protein X). HIV-1 infectious clone pNL4-3 was used to infect TZM-bl, PM1, Jurkat cell lines and human peripheral blood mononuclear cells (PBMC). Twenty-four hours post-infection, the infected or uninfected cells were harvested respectively for extraction of total RNAs and total cellular proteins, which were subsequently used in RT-PCR and Western-blotting respectively to quantify TSG101 and Alix, respectively. Our data showed that HIV-1 infection resulted in various influences on the expression of TSG101 and Alix in the cell lines and the primary PBMC. A down-regulation was mainly observed in the cell lines, whereas an up-regulation of TSG101 was identified in primary PBMC. Three patterns were observed for down-regulation, including dual down-regulation of TSG101 and Alix for Jurkat cells, single down-regulation of Alix for TZM-bl cells and marginal or no influence on PM1 cells. The dual down-regulation of Alix and TSG101 in Jurkat cells coincided with less expression of HIV-1 p24 protein. This is the first-line evidence that HIV-1 infection affects the expression of host factors TSG101 and Alix, the down-regulation of these molecules may influence the HIV-1 replication. The underlying mechanism remains to be addressed.

A new approach for sequencing virion genome of Chinese HIV-1 strains subtype B and BC from plasma / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Although it was widely accepted that full-length HIV genome sequences is important in studying virus genetic evolution and variation as well as developing vaccine candidate, to directly sequencing HIV-1 genome of virion RNA remains as a challenge worldwide. Up to date, no published genomic sequences from virion RNA are available for Chinese prevalent HIV-1 strains due to the absence of specialized protocol and appropriate lab equipments. In this study we developed a straightforward approach for amplifying and sequencing HIV virion RNA from plasma by modifying published protocols and further confirmed it is suitable to process Chinese samples.</p><p><b>METHODS</b>The methods for viral RNA extraction and gene amplification was modified and optimized as could be widely used in most Chinese labs. Gene alignment of Chinese HIV-1 strains was employed for designing specialized primer sets for Thai-B and BC recombinant strains. Based on comprehensively consideration of high variable gene region and recombinant breakpoints in BC recombinant strains, a three-amplicon strategy (including 4.3-kb gag-pol, 2.9-kb pol-env and 2.7-kb env-nef) was developed. In addition, one amplicon (9 kb near full-length genome) was also used in 32 samples with varied viral loads. All amplicons were directly sequenced by DNA automated sequencer.</p><p><b>RESULTS</b>Twenty-five percent (8/32) amplification efficiency was achieved by the one-amplicon strategy and 65.6% (21/32) by three-amplicon strategy. For one amplicon strategy, none of complete near full-length genome sequences was obtained by DNA sequencing. For three-amplicon strategy, 75% sequences were achieved in DNA sequencing. Amplification efficiency but not sequencing efficiency was closely associated with viral loads.</p><p><b>CONCLUSION</b>Three-amplicon strategy covering all encoding regions of HIV-1 is suitable for Thai-B and BC recombinant strains and could be potentially employed in less-well equipped Chinese labs.</p>

Construction and characterization of a new simian/human immunodeficiency viruses clone carrying an env gene derived from a CRF07_BC strain / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The CRF07_BC recombinant strain has been one of the most predominantly circulated HIV-1 strains in China, it is therefore necessary and urgent to develop a relevant animal model to evaluate candidate vaccines targeting HIV-1 CRF07_BC. A highly replication-competent simian/human immunodeficiency viruses (SHIV) construct containing the Chinese CRF07_BC HIV-1 env gene with the ability to infect Chinese rhesus monkeys would serve as an important tool in the development of HIV vaccines. The aim of this study was to examine whether SHIV XJDC6431 with the env fragment from a Chinese HIV-1 isolate virus could infect the human and monkey peripheral blood mononuclear cell (PBMC), establish infection in Chinese rhesus macaque.</p><p><b>METHODS</b>A SHIV strain was constructed by replacing the rev/env genes of SHIV KB9 with the corresponding fragment derived from the HIV-1 CRF07_BC strain. The infectious activity of the SHIV clones was determined in vitro in PBMCs from both non-human primate animals and humans. Finally, one Chinese rhesus macaques (Macaca mulatta) was infected with one SHIV via intravenous infusion.</p><p><b>RESULTS</b>One SHIV clone designated as SHIV XJDC6431, was generated that could infect macaque and human PBMC. The virus produced from this clone also efficiently infected the CCR5-expressing GHOST cell lines, indicating that it uses CCR5 as its coreceptor. Finally, the virus was intravenously inoculated into one Chinese rhesus macaque. Eventually, the animal became infected as shown by the occurrence of viremia within 3 of infection. The viral load reached 105 copies of viral RNA per ml of plasma during the acute phase of infection and lasted for 10 weeks post infection.</p><p><b>CONCLUSIONS</b>We conclude that SHIV XJDC6431 is an R5-tropic chimeric virus, which can establish infection not only in vitro but also in vivo in the Chinese rhesus macaque. Although the animal inoculated with SHIV XJDC6431 became infected without developing a pathologic phenotype, the virus efficiently replicated with a persistent level of viral load in the plasma. This suggested that the SHIV could be used as a tool to test candidate AIDS vaccines targeting the Chinese HIV-1 CRF_07BC recombinant strain.</p>

Molecular characteristics of HIV-1 CRF01 _ AE strains in Zhejiang province / 中华流行病学杂志

<p><b>OBJECTIVE</b>Using molecular epidemiology method to characterize human immunodeficiency virus type 1 (HIV-1) subtype CRF01 _ AE strains being prevailed in Zhejiang province.</p><p><b>METHODS</b>Gag fragments of the HIV-1 strains were amplified by nested-polymerase chain reaction (nPCR) from the DNA extracted from whole blood of HIV-1 infected individuals in Zhejiang province. PCR products were sequenced and analyzed by phylogenetic method.</p><p><b>RESULTS</b>81 HIV-1 subtype CRF01 _ AE sequences were identified from the 192 samples that sequenced successfully. As one of the dominant subtypes in Zhejiang, CRF01 _ AE was transmitted mainly by heterosexual or homosexual contact in local residents. In migrants living in Zhejiang, CRF01 _ AE were transmitted mainly by heterosexual contact or injecting drug use. There were three main clusters in the phylogenetic tree which bootstrap value was larger than 60. We named the clusters with group MIX (47 sequences), group SEX (7 sequences) and group MSM (12 sequences) based on the transmission. Pairwise DNA distances in the gag region within the three groups and between CM240 were different (P = 0.000). Data through the analyses of deduced amino acid sequences from the three groups showed that several signature amino acid sites were distinct from the same positions of the subtype reference strains.</p><p><b>CONCLUSION</b>The CRF01 _ AE strain prevailing in Zhejiang province was from several sources, transmitted by more than three different transmission routes, and becoming the main subtypes circulating in homosexual population in this study. More attention needs to be paid to the epidemic characteristic of CRF01 _ AE.</p>

Nef mutations in long-term non-progressors from former plasma donors infected with HIV-1 subtype B in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the specific amino acid variation in Nef that may be related to disease progression after infection with HIV-1 subtype B, a predominant strain circulating in China, and to determine whether changes in Nef secondary structure may influence different stages of AIDS development based on the concept that the Nef gene of HIV infection dramatically alter the severity of viral infection and virus replication and disease progression, and that long-term non-progressors (LTNP) of HIV infection are commonly associated with either a deletion of the Nef gene or the defective Nef alleles.</p><p><b>METHODS</b>The study subjects were divided into LTNP1(n=14), LTNP2 (n=16) and slow progressor (SP, n=19) groups for mutational analysis of the Nef sequence. The data were obtained by using Bioedit, MEGA, Anthewin and SAS software.</p><p><b>RESULTS</b>Residues in Nef TA(48/49) and K151 occurred more frequently in the LTNP group while AA(48/49) was more frequently observed in the SP group. Of the differences observed in the secondary structure comparison using Nef consensus sequences of these three groups, one was roughly corresponding to the Nef(48/49) mutation site.</p><p><b>CONCLUSION</b>TA(48/49), K(151), and AA(48/49) in the Nef gene might be associated with the different stages of HIV infection, and there may be a link between the Nef secondary structure and the progression of HIV-1 infection.</p>

Expression of CD66c (CEACM6) in adult acute leukemia and its significance / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the expression of CD66c (CEACM6) in adult acute leukemia and its significance.</p><p><b>METHODS</b>Acute leukemia cell lines HL-60, K562, LCL721.221 and Jurkat were cultured in vitro. RT-PCR and multi-parameter flow cytometry were applied to analysis of CD66c mRNA and protein expression respectively in the cell lines and patient' s bone marrow leukemic cells. Cytogenetic analysis for 199 bone marrow samples from leukemia patients and Minimal Residual Disease (MRD) detection for 25 CD66c positive B lineage ALL were performed.</p><p><b>RESULTS</b>(1) CD66c expression both on cell surface and in plasma were negative in all the cell lines. (2) Four of 127 AML (3.15%) (mainly of M2 and M4), and 28 of 79 ALL (35.44%) (all of B linage ALL) were CD66c positive the subtypes of the ALL being common B-ALL (20/54) and pre B-ALL (8/11) including 8 Ph + B-linage ALL. (3) Six-month relapse rate was significantly different between the MRD positive and negative patients. (4) CD66c mRNA was strongly expressed in B-linage ALL. For the cell lines, only the HL60 cells weakly expressed CD66c mRNA.</p><p><b>CONCLUSION</b>CD66c expression could be a useful bio-marker for the MRD analysis in ALL, and is closely associated with its transcription level.</p>