Non Hodgkin lymphoma, predominantly Diffuse Large B-cell Lymphoma (DLBCL) has been reported to have a significant association with Hepatitis B virus (HBV). We investigated the presence of different gene segments of HBV in plasma, B-cells and tumor tissues from DLBCL patients and explored the genetic variability of HBV within and across different compartments in a host using Next Generation Sequencing. Despite all 40 patients being HBV seronegative, 68% showed evidence of occult HBV. Sequencing of these gene segments revealed inter-compartment viral variants in 26% of them, each with at least one non-synonymous mutation. Between compartments, core gene variants revealed Arg94Leu, Glu86Arg and Ser41Thr while X gene variants revealed Phe73Val, Ala44Val, Ser146Ala and Ser147Pro. In tumor compartments per se, several mis-sense mutations were detected, notably the classic T1762A/A1764G mutation in the basal core promoter. In addition, a virus surface antigen mis-sense mutation resulting in M125T was detected in all the samples and could account for surface antigen negativity and occult HBV status. It would be interesting to further explore if a temporal accumulation of viral variants within a favored niche, like patients’ lymphocytes, could bestow survival advantage to the virus, and if certain pro-oncogenic HBV variants could drive lymphomagenesis in DLBCL.
Cell cultures of simian and human origin infected with two strains each of herpesvirus saimiri (HVS) and herpesvirus ateles (HVA) were compared for production of infectious virus and early and late antigens (EA, LA) in the presence and absence of the tumor promoting agent 12-0-tetradecanoylphorbol-13-acetate (TPA). Second, Epstein-Barr virus (EBV) infected human and simian lymphoblastoid cell lines of high and low cell passages were also compared for enhanced production of early antigen and virus capsid antigen (VCA) using two concentrations of TPA, owl monkey kidney (OMK) and squirrel monkey lung. Cell cultures infected with HVS and HVA with 20 ng/ml of TPA exhibited higher percentages of early and late antigen producing cells and contained 1.0-1.6 logs more virus. Such cells also had earlier cytopathic effects, larger plaques, and a 3-fold increase in the number of plaques. The TPA also enhanced HVS-EA, and LA both in OMK and human skin fibroblast (HSF) cells. The enhancement of EA was approximately 17.0% more in OMK cells and 4.0% more in HSF. The HVS-LA was 22% higher in OMK and 6.0% higher in HSF cells. Pretreatment of OMK cells with TPA prior to HVS or HVA infection showed only a 0.5-0.7 log enhancement of virus. A dose-response of TPA in P,HRl cells showed that both 20 and 40 ng/ml doses were able to enhance EBV, EA, and VCA significantly with peak enhancement at 40 ng/ml. Higher doses of TPA (60 and 100 ng/ml) resulted in considerable cell death and reduction in antigen production. TPA (20 and 40 ng/ml) stimulated both VCA and EA antigen production in P3HR1 and B95-8 cells, with lesser effects on other human and simian lymphoblastoid cells. However, the stimulation of EA and VCA with these doses of TPA varied for each cell line. Moreover, TPA-treated P,HRl, B95-8, and 407-1 cells on the average also produced 1.0-1.5 logs more virus than the untreated cells. The higher percentage of EA-VCA production from P3HRl and B95-8 cells and lower EA-VCA from other human and simian cells suggests that such virus-cell interaction may be influenced by in vitro passages.
Four young strain III/J rabbits of both sexes were inoculated with a single dose of prototype partially purified Herpesvirus saimiri (HVS) via IV and IM routes. All inoculated animals had enlarged lymph nodes, and significant levels of antibodies to HVS early, late, and membrane antigens were detectable during the infection. The animals died or were killed and HVS was isolated from the peripheral blood mononuclear cells and the various lymph nodes but not from the kidney. Microscopic examination showed that these animals had poorly differentiated lymphomas. The response of mononuclear cells to PHA from peripheral blood of infected animals showed depressed cell mediated immune responses. Humoral and cellular immunity responses during tumorigenesis were comparable to those reported in nonhuman primates with HVS-induced tumors. Thus, the inbred strain III/J appears to be an inexpensive suitable model for studies of oncogenic herpesvirus-induced cancers.
A facile and sensitive enzyme based electrochemical transducer has been fabricated for the detection of organophosporus compounds. The enzyme, acetylcholinesterase, was covalently immobilized on gold nanoparticles deposited electrochemically over screen printed carbon working electrode. The electrodes were characterized by scanning electron microscopy, atomic force microscopy and electrochemical methods. The enzyme-substrate reactions and sensing studies were carried out at room temperature by cyclic voltammetry. The developed biosensor gave optimum response within 25 sec. for a substrate (acetylthiocholine) concentration of 0.0699 mM at pH. The electrode showed a linear response in the range between 0.2 and 1 ppb, and the detection limit was determined to be 0.6 ppb. Moreover the biosensor exhibited good reusability and stability thus, making it a promising tool for on-field detection of organophosphorus compounds.
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