Temporal VEGFA responsive genes in HUVECs: Gene signatures and potential ligands/receptors fine-tuning angiogenesis.

Vascular Endothelial Growth Factor-A (VEGFA) signaling is crucial to the cellular processes involved in angiogenesis. Previously, we assembled a network of molecular reactions induced by VEGFA in human umbilical vein endothelial cell populations. Considering transcriptome as a read-out of the transcriptional and epigenomic regulatory network, we now present an analysis of VEGFA-induced temporal transcriptome datasets from 6 non-synchronized studies. From these datasets, applying a confidence criterion, a set of early VEGFA-responsive signature genes were derived and evaluated for their co-expression potential with respect to multiple cancer gene expression datasets. Further, inclusive of a set of ligand-receptor pairs, a list of ligand and receptor signaling systems that potentially fine-tune the endothelial cell functions subsequent to VEGFA signaling were also derived. We believe that a number of these signaling systems would concurrently and/or hierarchically fine-tune the signaling network of endothelial cell populations towards the processes associated with angiogenesis through autocrine, paracrine, juxtacrine, and matricrine modes. By further analysis of published literature on VEGFA signaling, we also present an improved update-version of our previous VEGFA signaling network model in endothelial cells as a platform for analysis of cross-talk with these signaling systems.

Predominance of antibodies to hepatitis C virus envelope proteins in various disease statuses of hepatitis C.

The antibody profile to various proteins of hepatitis C virus (HCV) was studied in 113 patients positive for HCV RNA in various disease statuses of hepatitis C (HC). A single peptide (E2/NS1, aa 413-436 of HCV polyprotein) chosen from a conserved region at the C-terminus of the hypervariable region (HVR) HVR1 of HCV was found to be sufficient for reliable diagnosis of the infection, even in the acute phase. Six hundred and one suspected HC cases and 200 voluntary blood donors were tested by this peptide. The sensitivity of detection of HCV antibodies by this peptide did not increase with addition of peptides from other HCV proteins. Our results clearly demonstrate that antibodies to HCV envelope proteins occur in a higher percentage of the infected population than those to other proteins. This emphasizes the necessity of using representative sequences from HCV envelope proteins in diagnostic immunoassays of this viral infection.

Analysis of human immune response to potential hepatitis C viral epitopes.

A peptide-based enzyme immunoassay (PBEIA) has been developed using synthetic peptides whose sequences were selected from the core, envelope and non-structural regions of the prototype hepatitis C virus (HCV) genome. Results of PBEIA of sera obtained from several patients with various liver disorders were compared to those of commercial enzyme-linked immunosorbent assays (ELISA) and reverse transcription-polymerase chain reaction (RT-PCR). A large number of samples, which were repeatedly negative in commercial ELISA, were positive in PBEIA. There was a good correlation between the results of PBEIA and RT-PCR. The developed PBEIA proved to be a sensitive assay that had high specificity and was capable of detecting antibodies in various HCV-related liver disorders including the acute phase of the infection.

Excretory/secretory antigens from a bovine filarial parasite cross react with human antifilarial antibodies.

Certain excretory/secretory proteins released by adult females of the bovine filarial parasite, Setaria digitata, along with the release of microfilariae when chromatographically analysed has three major protein fractions of molecular weights 70 kD (ESF1), 16.5 kD (ESF2) and 11 kD (ESF3). Of these ESF2 and ESF3 cross reacted with antibodies from Wuchereria bancrofti infected humans. ESF2 was more specific and accurate in detecting human filarial infection. Similar proteins secreted by human filarial parasites could be targets for combating the disease by cure or control.

Diversity of Hepatitis C virus in Southern India Based on 5'UTR Sequence.

Hepatitis C virus (HCV) exhibits genotype-specific variations in geographical distribution as a consequence of drug and immune induced evolution. Present study was aimed at discerning the distribution and prevalence of the various genotypes and subtypes of HCV in southern India. The HCV positive patient's serum was collected from different hospitals and blood banks from the states of Kerala, Tamil Nadu, Andhra Pradesh and Karnataka. Among 114 HCV positive samples, we could find only 44 isolates that are found both positive in ELISA and RT-PCR. From these samples 5' untranslated region (5'UTR) were amplified, sequenced and sub typed. Analysis of 5'UTR region of the 44 isolates shows that, genotypes 1, 3, 4 and 6 are present with genotype 3 being the most frequent. The present study shows that HCV genotype 3 subtype B was the most prevalent, forming 47.7 % among the population in southern India. The present study urges for discovering novel therapeutic agents that should be specific to genotype 3 subtype B, for the management of HCV in southern India.

Syntheses of immunodominant peptide regions of hepatitis C viral pathogens using PS-BDODMA resin: a single peptide derived from the conserved domain (E2/NS1) was highly effective in detecting anti-HCV antibodies.

Peptides were synthesized with very high purity and yield on a highly solvating copolymer of 1,4-butanediol dimethacrylate cross-linked polystyrene support (PS-BDODMA). The polymer was synthesized by radical aqueous suspension polymerization using toluene as the diluent and 1% polyvinyl alcohol as the suspension stabilizer. The supports were highly resistant to various chemical reagents and solvents that are frequently used in polypeptide synthesis. The peptides synthesized on this support were designed from the core (C), envelope (E1 and E2) and nonstructural protein (NS1-NS5) regions of the prototype hepatitis C viral (HCV) polyprotein, and were used to develop a peptide-based immunoassay (PBEIA) for the detection of HCV antibodies. The purity of these peptides was tested by HPLC. Peptide identity was confirmed by amino acid analysis and MALDI-TOF-MS. A single peptide chosen from a conserved area (E2/NS1) at the C-terminus of the hypervariable region (HVRI) was found to be sufficient for effective and reliable diagnosis of HCV infection in infected individuals, as well as also apparently healthy individuals. The CD spectrum of the peptide shows no preference for any ordered secondary structure. When used, peptide mixtures from various protein regions of HCV reduced the sensitivity and reliability of the diagnosis partly because of epitope masking.