Day 2 :
XENOTOX Inc, USA
Time : 10:00-10:40
Since 2005 - a CSO at XENOTOX, Inc. Have a medical background (M.D., 1970), Ph.D. in Biochemistry (1973), D.Sc. in Molecular Toxicology (1983). Hold progressively responsible positions: Group Leader (74-79), Head of the Laboratory (1979-87), Department Chair (1987-91), all at Russian Academy of Science. In the US: a Senior Scientist at NCI, NIH (1991-95), Professor (since 2010 - visiting) at Mount Sinai School of Medicine (1995-to date). Author of 5 monographs and 250+ peer reviewed publications. By using enzyme-kinetic and inhibitory analyses, pioneered in revealing TCDD-induced CYP1B1 (FEBS Letters, 1987). Invented the recombinant and TCDD-induced microsomal and isolated monooxygenase isoforms CYP1A1 and CYP1A2, to study regulatory effects of bioflavonoids on procarcinogens metabolism in humans (BBA, 1994). Since the discovery of trans-activation effect of TCDD on HIV-1 (BBRC, 1991), have established Xenobiotical Virology, a biomedical discipline dealing with mechanisms of dioxin effects on DRE-containing genes of human viruses, transcription factors and cytokines linked to inflammation and malignancy pathways.
Objective: The concept emerged from our findings indicated transactivation of the HIV-1 and hepatitis B virus (HBV) in human cells by 30-150 ppt 2,3,7,8-TCDD (dioxin), a potent carcinogenic xenobiotic with extremely long serum half-life in humans. Up-regulation of cytomegalovirus (HCMV) in human cells was shown using 10 ppq dioxin, a level much lower than current background level in the general population (~4 ppt). Eventually, human viruses were suggested novel target genes of cellular dioxin receptor (AhR/Arnt) complex. This complex had been primarily shown binding to dioxin-responsive elements (DRE) within numerous mammalian target genes, and the effect of number of DRE on dioxin gene-regulating activity was established. Here, going along with the above experimental data, potentially active DRE were detected and quantified in regulatory area of several cancer-related human viruses.
Methods: Productions of infectious HIV-1 in MT4 cells, HCMV in THP-1 cells, and HBV in HepG2 cells were determined using plaque assay. Viral DNAs were determined by hybridization and PCR. A computational search for DRE in viral genes was performed by SITECON, a powerful tool for detecting conservative conformational and physico-chemical properties in transcription factor binding site alignments and for site recognition. Earlier SITECON efficiently detected all proved functional DREs in human CYP1A1 and CYP1B1, as well as DRE in human genes encoding AhR and proteins of its cytosolic and nuclear complexes.
Results: A total of 13 bona fide DRE, all including the substitution intolerant core sequence (5’-GCGTG-3’) and SITECON-selected adjacent variable sequences were used here to detect the above properties for the DRE site, and conformational similarity score threshold of 0.95 was utilized to rank identified DRE. Eventually, for HCMV it was found that regulatory region of the genes encoding IE gp/UL37 has 5 DRE, 1.65 kb/UL36 – 6 DRE, pp65 – 7 DRE, pp71 – 7 DRE, and pp150 –10 DRE. Contrarily to that, each gene of different HBV proteins, as well as HIV-1 LTR, has a single promoter DRE. If juxtapose DRE numbers with experimental results, then the most susceptible candidate virus to be augmented with body burden dioxin is that one possessing at least similar to HCMV number of DRE. To this end, SITECON recognized that several known cancer-associated human viruses possess multiple DREs in their promoters. Thus two Epstein-Barr virus (EBV) promoters, L1A and L1, each contain 16 DRE, and gene of EBV R1 145K has 11 DRE. Also, genes encoding some major proteins of herpes simplex virus (HSV) type 1 have from 7 to 8 promoter DRE.
Conclusion: The above support the concept, and provide evidence that sub-nanomolar dioxin is able to activate DRE-containing viruses. Mechanistic data obtained allow searching for inhibitors of viremia and virally driven malignancies among antagonist ligands of cytosolic AhR, and modifiers of AhR/Arnt complex binding to viral DRE.
Alexandria University, Egypt
Keynote: Molecular diagnosis and prevalence of Human metapneumovirus infection among Egyptian infants with acute viral bronchiolitis
Time : 10:40-11:20
Gamal El Sawaf is a Professor of Microbiology and Immunology Medical Research Institute, Alexandria University, Egypt. He is a nationally recognized leader in infectious diseases. He was graduated from the Faculty of Medicine, Alexandria University in 1979. He has obtained his PhD in 1993 and his Post Doctor training course in the Laboratory of Infectious Diseases (Cattedra Di Clinica Delle Malattie Infettive) University of Rome, Tor Vergata. He was appointed as the Head of Microbiology Department in 2008 and the Director of the Medical Technology Center in 2010 and finally, the Dean of MRI. His main fields of research activities are in the clinical aspects pathogenesis and therapy of HCV, HIV and HHV-8 infection and epidemiology and molecular characterization of hepatitis viruses in Egypt. He has acted as a Referee for a variety of national and international scientific journals and as a Referee of research projects of the Alexandria University and of the STDF projects. He is a Member of the American Society of Microbiology, The Egyptian Society of Microbiology and Egyptian Society of Immunologists. He is a Project Leader of several research programs on HCV, HHV and TB
Background & Aim: Despite improved methods for identifying viral pathogens in cases of acute bronchiolitis, the etiology remains undetermined in a significant number of patients. Human metapneumovirus (hMPV) is one of the emerging respiratory viral pathogen that causes a spectrum of illnesses that range from asymptomatic infection to severe bronchiolitis. The aim of this study was to identify the prevalence of hMPV that contribute to bronchiolitis in infants and young children in Egyptian populations and to determine the comprehensive clinical characterizations of disease.
Methods: Nasal swabs for viral detection were obtained from 117 Egyptian infants, clinically diagnosed as acute bronchiolitis at the Alexandria University Children’s Hospital during the period from January to April 2015. Clinical and demographic data were obtained from parents and medical records; hMPV was detected by means of a reverse-transcriptase polymerase-chain-reaction assay. Indirect immunofluorescent assay (IFA) assay methods were used to detect the presence of any of the most common respiratory viruses (respiratory syncytial virus (RSV), Influenza virus A, Parainfluenza virus types 1-3 and adenovirus) that might be involved in infection.
Results: In our study, 76% of the cases were positive at least to one or more of the seven mentioned viruses. hMPV was detected in 19 (16 %) of the 117 children. The age-related incidence of hMPV infection was higher than that of RSV-infected children. Only 5 patients (4%) had hMPV as the sole respiratory viruses, whilst 14 cases (12%) had a co-infection of hMPV with other respiratory viruses. Clinical symptoms of hMPV were found to be similar to those seen with other respiratory viral infections. The most significant risk factors for acute bronchiolitis in our study groups were young age, exposure to tobacco and living in overcrowded environments.
Conclusions: Human metapneumovirus infection is a leading cause of respiratory tract infection in the first 2 years of life, with a spectrum of disease similar to that of RSV. The risk factors identified in this study may be considered for interventional studies to control infections by these viruses among young children from developing countries. Further investigations to better characterize hMPV infection and its clinical effect are needed