Detection and analysis of anti-latent membrane protein 2A antibodies in the sera of patients with Epstein-Barr virus associated malignancies / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Epstein-Barr virus (EBV) associated malignancies with a Type II latency gene expression pattern, such as Hodgkin's disease, and nasopharyngeal carcinoma (NPC), frequently express the EBV antigen latent membrane protein 2A (LMP2A). We expected to establish a highly expressing LMP2A yeast cell strain and get the high quality LMP2A protein, which was used for detection, analysis and characterization of its antibodies in various patients' sera of EBV associated malignancies.</p><p><b>METHODS</b>The plasmid pPICZalphaA-LMP2A containing the full length of LMP2A cDNA was constructed and transformed to Pichia pastoris GS115 to express LMP2A protein. After fermentation and purification, the LMP2A protein was used as an antigen to detect anti-LMP2A antibodies (Abs) in the sera of patients with EBV-associated malignancies in enzyme linked immunosorbent assay (ELISA) or Western-blot.</p><p><b>RESULTS</b>LMP2A was expressed successfully with an expected molecular weight of approximately 54 kD and Abs to LMP2A were strikingly specific to NPC. Two-thirds or more sera from NPC patients were positive for anti-LMP2A immunoglobulin G (IgG) Abs. The antibodies were absent from the sera of other EBV-associated diseases except a small fraction of the gastric carcinoma. Comparing anti-viral capsid Ags (VCA) IgA and LMP2A IgA titers in the sera from 76 NPC patients, only 55% were positive for anti-LMP2A IgA Abs while 70% were positive for anti-VCA IgA. However, we found that 3 sera negative for VCA IgA were positive for LMP2A IgA.</p><p><b>CONCLUSION</b>The results suggested the potential significance of LMP2A specific Abs for the diagnosis of EBV-associated malignancies, especially NPC.</p>

Expression of HBcAg in eukaryotic cells by retroviral vector mediated gene transfer / 中华实验和临床病毒学杂志

<p><b>BACKGROUND</b>To construct recombinant retroviral vector expressing HBcAg in eukaryotic cells.</p><p><b>METHODS</b>The HBV core gene fragment was amplified by using PCR from pADR which contains complement nucleotide sequence of HBV subtype adr and cloned into retroviral expression plasmid pLXSN, then transfected into packing cell (PT67) with lipofec AMINE. After 2-3 weeks selection with G418, large colonies were isolated and transferred to individual plates. Virus-containing medium was collected and used to infect NIH3T3, EL4 and mouse bone marrow derived dendritic cells(DC). DNA was extracted from infected cells and tested by PCR. Indirect immunofluorescence and FACS were used to detect the expression of HBcAg. Cell mediated immunity of immunized C57BL/6 mice with transduced DC was analyzed.</p><p><b>RESULTS</b>The insertion of HBV core gene fragment in the recombinant retroviral plasmid was confirmed by PCR as well as enzyme digestion with EcoR1 and BamH2. The viral titer reached 3 x 10(5) CFU/ml. The result of PCR showed that the HBV core gene had been integrated into the genome of infected NIH3T3 cells. Indirect immunofluorescence and FACS analysis showed that HBcAg had been expressed in these cells. HBcAg specific CTL responses could be generated in mice immunized with retrovirus transduced DC.</p><p><b>CONCLUSIONS</b>HBV core gene had been integrated into eukaryotic cells with retroviral vector and target gene had been expressed efficiently. These results may have some impact on gene therapy of chronic hepatitis B.</p>

Modulation of lianbizi injection (andrographolide) on some immune functions / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of andrographolide on immune functions and the immune mechanism of its clinical application.</p><p><b>METHOD</b>The amounts of IFN-alpha, IFN-gamma, TNF-alpha, IL-8 in the peripheral blood mononuclear cells(PBMCs) culture supernatants deal with by different concentrations of LianBiZhi (LBZ) injection made of andrographolide were detected by biological activity test or ELISA in vitro. The effects of LBZ injection on macrophage phagocytotic function and natural killer cells cytotoxicity were examined by means of macrophage to phagocytize cock erythrocyte and measurement of lactate dehydrogenase(LDH) activity released from the damaged cells, respectively.</p><p><b>RESULT</b>The LBZ injection could promote IFN-alpha, IFN-gamma, TNF-alpha inductions of PBMCs, but had no effect on IL-8. At the same time, the LBZ injection could not only enhance the phagocytosis activity of peritoneal macrophage from guinea pig to phagocytosis cock erythrocyte, but also augment the cytotoxicity mediated by natural killer cells from PBMCs to damage the K562 cell lines.</p><p><b>CONCLUSION</b>Andrographolide is an immunostimulant agent which can modulate both antigen specific and nonspecific immune function by means of its natural killer cells and macrophage and cytokines induction.</p>