Expression of hepatitis B surface antigen in tobacco cell suspension cultures

Hepatitis B virus ' s ' gene coding for surface antigen was cloned into plant transformation vectors pHER100 and pHBs100 with and without endoplasmic reticulum retention signal, respectively. Transformed tobacco cell lines were analyzed for the integration of the transgene by PCR and Southern blot hybridization. Expression levels as determined by ELISA showed maximum expression levels of 2 microg HBsAg gm(-1) fresh weight and 10 ng mL(-1) of spent medium in pHER100 transformed cells. Western blot analysis confirmed the presence of 24 kDa band specific to HBsAg in the transformed cells. HBsAg was expressed both as intracellular and secreted forms in pHER100 transformed cells. The buoyant density in CsCl of HBsAg derived from pHBs100 transformed tobacco cells was determined and found to be 1.095 g mL(-1). HBsAg obtained from transformed tobacco cells is similar to the human serum derived one in buoyant density properties. This is the first report on the secretion of HBsAg particles by plant cells into the cell culture medium.     

Structure based virtual screening of anticanerous polyphenolic phytocompounds against G-protein coupled receptor and identification of potent antagonist ligand(s) through molecular docking

Design of potential drug-like candidates for cancer is of interest in recent years. We used 60 compounds which are known to have the potential to down regulate Nuclear Factor kappaB (NFκB) for this study. The compounds were assessed for Lipinski's RO5 and ADMET properties. Allixin, anethole, capsaicin, linearol and syringic acid satisfied both Lipinski's RO5 and ADMET properties. These compounds showed strong molecular interaction with receptor GPCR55 indicating they have ability to block GPCR55. Thus, their role in anticellular proliferation and induction of apoptosis is implied.     

Phylogeny of the M superhaplogroup inferred from complete mitochondrial genome sequence of Indian specific lineages

Background  

Phylogenetic analysis of human complete mitochondrial DNA sequences has largely contributed to resolving phylogenies and antiquity of different lineages belonging to the majorhaplogroups L, N and M (East-Asian lineages). In the absence of whole mtDNA sequence information of M lineages reported in India that exhibits highest diversity within the sub-continent, the present study was undertaken to provide a detailed analysis of this haplogroup to precisely characterize the lineages and unravel their intricate phylogeny.     

HIV ENV glycoprotein-mediated bystander apoptosis depends on expression of the CCR5 co-receptor at the cell surface and ENV fusogenic activity

HIV-1 infections lead to a progressive depletion of CD4 cells culminating in AIDS. The coreceptor usage by HIV varies from CCR5 (R5) tropic early in infection to CXCR4 (X4) tropic in later infections. Although the coreceptor switch from R5 to X4 tropic HIV is well associated with progression to AIDS, the role of CCR5 in disease progression especially in patients infected exclusively with R5 isolates throughout the disease remains enigmatic. To better understand the role of CCR5 and R5 tropic HIV envelope in AIDS pathogenesis, we asked whether the levels of CCR5 and/or HIV Env-mediated fusion determine apoptosis of bystander cells. We generated CD4(+) T cell lines expressing varying levels of CCR5 on the cell surface to show that CCR5 expression levels correlate with bystander apoptosis induction. The mechanism of apoptosis involved caspase-3 activation and mitochondrial depolarization and was dependent on gp41 fusion activity as confirmed by fusion-restricted gp41 point mutants and use of the fusion inhibitor T20. Interestingly, lower levels of CCR5 were able to support virus replication in the absence of bystander apoptosis. Our findings suggest that R5 HIV-1-mediated bystander apoptosis is dependent on both CCR5 expression levels as well as fusogenic activity of the Env glycoprotein.