Day 2 :
- Track 9: HIV Host Interactions
Track 10: Current HIV Researches and Treatment
Track 11: Antiretroviral Drug Discovery & Development
Track 12: Current Research on Retroviruses
Track 13: Novel Therapeutic Approaches
Session Introduction
David Harrich
QIMR Berghofer Medical Research Institute, Australia
Title: Inhibiting HIV-1 reverse transcription by targeting the reverse transcription complex
Time : 09:15-09:40
Biography:
David Harrich working as a researcher at QIMR Berghofer Medical Research Institute, he belongs to Australia. Associate Professor David Harrich has found a promising way of stopping HIV from causing AIDS. The human immunodeficiency virus (HIV) is currently treated with a cocktail of drugs to stop the virus from causing acquired immunodeficiency syndrome (AIDS). But there is no cure or vaccine
Abstract:
Reverse transcription, the process which converts viral genomic RNA into a double strand DNA, is the central defining feature of HIV-1 replication and a major target for anti-retroviral therapy. Along with reverse transcriptase (RT), viral protein including IN, CA, and Vpr and cellular proteins including eukaryotic translation elongation factor 1A (eEF1A) are important for the process. We previously showed that eEF1A stabilized the RTC in cells and was important for late steps of reverse transcription. Our recent experiments show a direct interaction between RT and eEF1A that can be down regulated by amino acid substitutions in the RT thumb domain, and which lead to downregulated late reverse transcription. Moreover we show that drugs which bind to eEF1A are potent inhibitors of reverse transcription. Experiments to determine if eEF1A binding drugs negatively affect the RTC in cells will be presented. Recently we also showed that a Tat mutant called Nullbasic inhibits reverse transcription. Our recent data shows that Nullbasic is an RT binding protein that is found in viral particles. In vitro uncoating assays show that virions containing Nullbasic undergo accelerated uncoating kinetics, and analysis of cells infected with HIV-1 containing Nullbasic indicates that the levels of RTCs are reduced, consistent with the uncoating defect. We have recently made Jurkat cell line expressing Nullbasic which appear to be highly resistant to HIV-1 infection. In chronically infected Jurkat cells, introduction of Nullbasic can decrease HIV-1 mRNA levels from 150-to 800 fold. The mechanisms responsible for strong inhibition of HIV-1 will be presented. The combined evidence indicates investigations of interaction between RT and viral and cellular proteins could enable new antiviral strategies.
Harold C Smith
University of Rochester, Department of Biochemistry and Biophysics &OyaGen, USA
Title: Drug Leads that Inhibit Vif and Enable APOBEC3G are Broadly Neutralizing of HIV1 Clades and Drug-resistant Strains
Time : 09:40-10:05
Biography:
Harold Smith is a tenured professor of biochemistry and biophysics at theUniversity of Rochester, School of Medicine and Dentistry. Dr. Smith¹sprimary function at the University is basic research and in this contexthe is fully engaged in biomedical laboratory research as well as trainingpostdocs, graduate and undergraduate students. The Smith lab¹s primaryinterest is understanding the composition, regulation and structure ofmacromolecular complexes involved in regulating gene expression at thelevel of messenger RNA expression and processing. Our focus is on aplatform of enzymes that change the genetic code at the DNA or RNA levelby deaminating cytidine to form uridine. Current data suggest that thisfamily of cytidine deaminase function with other proteins (auxiliaryproteins) as holoenzymes complexes which we refer to as editosomes (forRNA) or mutasomes (for DNA). RNA editing or DNA mutational activity bythese enzymes affect the protein coding capacity of mRNAs and thereby candiversify the proteins that are expressed by cells (the proteome). In 2003he founded OyaGen, Inc as a drug discovery and drug development biotechfocused on anti retroviral therapeutics.
Abstract:
HIV Viral infectivity factor (Vif) evokes the destruction of the host restriction factor known as APOBEC3G (A3G).Vif dimerization has been shown to be essential for Vif binding to A3G and A3G degradation. Experimental data show that in the absence of Vif, virion-assembled A3G will hypermutateproviral DNA during reverse transcription. The open questions are: can Vif be successfully drugged and by sparing A3G, will hypermutation activity be sufficient to inhibit viral replication? High throughput screening (HTS) assays were developed using FRET for Vif dimerization. The screens were used to select compounds with dose-dependent signals by preventing Vif FRET. A secondary assay for Vif-dependent A3G degradation was used to identify compoundsthat preserved A3G. These were triaged for the ability to inhibit pseudotyped HIV replication and to have low cytoxicity. Ion torrent sequencing of integrated viral genomes revealed extensive hypermutation characteristic of A3G preferences. Following medicinal chemistry, a lead was tested in a seven day spreading infection in PBMC. TheVif dimerization FRET assay provided a robust HTS method applicable to a large library of drug-like molecules. Quantitative HTS followed by orthogonal secondary screen and cytotox counter screening enabled selection of limited number of chemistries for pseudo typed viral testing. A lead (SMVDA) was selected with nanomolar IC50. By impairing Vif dimerization, A3G degradation was reduced and viral particle incorporation of A3G was enhanced. Proviral DNA isolated form target cells showed numerous tracts of dG to dA hypermutation that corresponded to multiple nonsense codon and sense changes. 17 different clades and 8 drug resistant strains of HIV infecting PBMC were sterilized by seven days following a single dose of SMVDA. Conclusions: Drugging Vif led to massivedG to dAhypermutation of HIV proviral DNA, such that the protein coding capacity of the virus would be severely compromised. Inhibitors of Vifare broadly neutralizing and inhibited all drug resistant strains of HIV tested. DruggingVif therefore is achievable and the data suggest that this will serve as a firewall for viremia induced by activating reservoirs as well as a solution for rescue and salvage therapies.
Hone Anagaw
Jimma University of Ethiopia, Ethiopia
Title: Assessment of client satisfaction and adherence on art services in Jimma University specialized hospital, South West Ethiopia
Time : 10:05-10:30
Biography:
Hone Anagaw is working in Jimma University, which is located in Ethiopia
Abstract:
Background: Client satisfaction and adherence on ART service were an important task for care providers to increase service utilization and to respond to HIV emergency; however, Other provider-defined criteria is far from ideal if as a result of the service that the patient is unhappy or dissatisfied. There is, then, a sound rationale for making the organization and delivery of health service responsive to consumer opinion. Objective: The aim of this study is to assess client satisfaction and adherence on an ART service provision in Jimma University specialized hospital. Methods: A cross sectional study involving both quantitative and qualitative data collection methods was conducted from May 1-30, 2010. A total of 337 Adult PLWHA on ART for at least 3 months were the study participants. Systematic sampling technique was used to select the study subjects. Data were collected using structure questionnaire, check lists and semi structure interview guide. After clearing and checking for consistency data were coded, entered and univariate and multivariate analysis was carried out using SPSS version 16.0. qualitative data‘s were transcribed and narrated under themes. Result: A total response rate of 100% from 337 sample size was obtained. Among those 203(60.2%) were females. Two hundred thirty one (68.5%) of respondents scores ≥ mean which means 68.5% satisfied relationship with their care providers. In this study, in which adherence was measured using a self report method, 95.5% of patients were adherent with ≥95% prescribed doses. Marital status, occupation, and waiting time was found to be associated significantly with adherence [OR-136, 95% CI 019 - 0.997], [OR 9.341, 95%CI 1.189-73.358], [OR 9.88E-24, 95% CI 1.759E-24-5.550E-23] respectively. Conclusion and Recommendation: The result of the study showed that assessment of client satisfaction and adherence in Jimma University specialized hospital is high adherence rate inspite of satisfaction. Overall client satisfaction and patient, provider relationship satisfaction rate were low. However measured by self report method, adherence to ARV treatment in this study was seems to be encouraging. Working with other religious leaders, and community leaders to strengthen adherence status are recommended.
David Sando
Dar es Salaam, Tanzania
Title: Temporal Trends in Clinical Characteristics and 12-months Outcome of Patient’s enrolled in ART program during 2004 to 2012 in Dar es Salaam, Tanzania
Time : 10:45-11:10
Biography:
Dr. Sando worked for 5 years as the Monitoring & Evaluation Team Lead at the Ministry of Health and Social Welfare in the Epidemiology Unit of the National AIDS Control Programme (NACP). Prior to his work at NACP, Dr. Sando was a Medical Officer In-Charge at the Tanzania Heart Institute (THI), supervising and overseeing daily medical activities at the facility. Dr. Sando has extensive research experience, mostly pertaining to HIV/AIDS in Tanzania. Dr. Sando received his Doctor of Medicine at Muhimbili University College of Health Sciences (MUCHS), a Master’s of Science in Health Monitoring and Evaluation at Jimma University in Ethiopia, and a Master’s of Science in Epidemiology from Harvard School of Public Health..
Abstract:
Background: The impact of expanded access to HAART on the epidemiology of patients enrolled in HIV care and treatment services is poorly documented. In this study we describe the temporal trends in; a) baseline characteristics b) 12-months lost to follow up c) mortality of patients in 28 public facilities in Dar es Salaam, Tanzania. Methods: Epidemiological, clinical and immunological data of adult patients aged 15 years and above, enrolled October 2004 to September 2012 were collected at baseline and 12 months. Year of enrollment was treated as independent variable and binomial logistic regression model was used for trend tests. P-values under 0.05 were considered significant. Results: A total of 109943 adults with median age of 35 years were enrolled during the study, 71% were female. There was increased mean baseline CD4 (163 to 227 cells/uL, `P<0.01), decreased proportions with advanced disease stages III or IV (72% to 67%, P<0.01), decrease percent’s diagnosed with PCP (P=0.04). We found no significant differences in; mean cholesterol level (P=0.08), systolic blood pressure (P=0.3), esophageal candidiasis (P=0.052), diagnosed with TB (P=0.13) and for women those who are pregnant during first visit to the clinic (P=0.8). There was an increase in mean Hemoglobin level (9.9 to 10.5g/ dL, P=0.02), it was found that over time there was a decrease in enrollment in hospital level facilities and increase in health centers and dispensaries (P<0.001). Increase in patients who are lost to follow up in the first 12-months, 8.9% (2004/05) to 18% (2009) which started to decrease in following years (P < .0001). We also found decrease in both patients who are reported dead within 30 and 90 days after enrollment (P<0.01). There was overall increase in 12-months mortality rate from 8.8%(2004/05) to 21% (2008), which was followed by decrease from 15% (2009) to 3.7% in 2012 (P< .0001). Conclusion: Between 2004 and 2012 the expansion of HAART services has demonstrated positive impact both in early enrollment, retention and survival of PLHIV. The findings highlight the need to escalate efforts to improve access to HIV diagnostic testing and HAART.
Erwann Loret
ETRAV laboratory (Aix Marseille University/CNRS), France
Title: HIV Extracellular Tat: Myth or Reality?
Time : 11:10-11:35
Biography:
He obtained Ph. D. in France, then he went to USA in 1990 for a first post-doc in the department of biophysics and biochemistry at Oregon State University, followed by a second post-doc in 1992 in the department of chemistry at the University of California, Davis. He was recruited as full senior scientist in 1992 in CNRS (Centre National de la Recherche Scientifique), which is the main French national agency for scientific research. Erwann Loret obtained the GlaxoSmith Kline Drug Discovery and Development Award from an American scientific committee for his contribution to HIV research, the Medal of Honor from the Aix Marseille University and the French National Institute for Intellectual Properties Award (Institut National de la Propriété Industrielle). He is the director of a CNRS lab entitled “Etude de Tat et Recherches Appliquées sur le VIH-1” (ETRAV) located in the faculty of Pharmacy at Marseille. ETRAV is the only lab working on AIDS in Aix Marseille University. He is member of the Editorial Board of scientific journals. He is author and co author of 55 scientific publications referenced in PUBMED (two are in press), most of them having a high impact factor (PNAS, EMBO, JBC, RETROVIROLOGY etc …) and five international patents (PCT) on active compounds against the HIV-1 Tat. His main field of interest is related to the HIV-1 Tat proteins and he is the coordinator of a Phase I/II clinical trial of a vaccine targeting Tat at Marseille that began in 2013.
Abstract:
The human immunodeficiency virus type 1 (HIV) eradication will require elimination of HIV infected cells. No antiretroviral treatments (ART) or vaccine approaches have been able to reduce significantly the level of HIV infected cells in peripheral blood. This inefficacy is generally explained by the presence of a major reservoir of latent HIV infected cells in the central nervous system (CNS) that would be a sanctuary where Cytotoxic T Lymphocytes (CTL) have no access and would refresh peripheral blood with activated HIV infected cells. In this review, the presence of a major reservoir in the CNS appears to be inconsistent with recent clinical studies measuring HIV DNA. The major reservoirs are gut tissue, rectal tissue and the peripheral blood where HIV infected cells survive in an environment containing CTL. Extracellular Tat might protect HIV infected cells from CTL due to its capacity to cross CTL membranes and trigger apoptosis. Evidences of Tat secretion from HIV infected cells are shown with the detection of Tat antibodies in different clinical studies. Presence of neutralizing Tat antibodies in cohorts of patients who were exposed to HIV but who are now seronegative is described. The conclusion of this review is that a vaccine eliciting neutralizing antibodies against Tat might significantly reduce the level of HIV infected cells, what ART or other vaccine approaches have been unable to achieve now. It could be a first step towards HIV eradication.
Sonia Escaich
BIOSANTECH, France
Title: Tat Oyi-based candidate therapeutic vaccine: a successful phase 1 clinical trial in HIV-1 infected patients
Time : 11:35-12:00
Biography:
Dr. Sonia Escaich, Ph.D., served as the Chief Scientific Officer at Mutabilis S.A. She is the Member of the Executive Board at Mutabilis S.A. Her initial appointment involved heading up the virology unit in the Sandoz/Systemix Inc. joint venture, working on anti-HIV gene therapy. She later managed various laboratory units in the anti-infective research department at Rhone-Poulenc /Aventis in France; first in the field of antivirals then in the antibacterial department, where she setup and develop new antibacterial projects, including exploratory projects based on virulence inhibition. Dr. Escaich serves as a Director of Mutabilis S.A. She holds a PhD in Microbiology with a specialization in Virology, and a post doctorate in Sandoz in Vienna.
Abstract:
Background: Tat protein is an HIV virulence factor involved in several physiopathological pathways, and shown to be expressed even during HAART. Several studies have shown that an immune response to HIV-1 Tat is correlated with the control of HIV replication in animal models and a slower disease progression in human. Tat-based vaccine candidates were assessed in clinical trials with variable results. Our rational for using Tat Oyi as a novel vaccine candidate is provided by the isolation of the HIV-1 Oyi defective clone in an asymtomatic Gabonese. The Tat Oyi mutant is defective for transactivation. Further more, antibodies generated against Tat Oyi were able to cross-recognize all Tat variants of the five main world HIV-1 clades. Methods: The Tat Oyi-based vaccine candidate was designed using the full length Tat. The immune response to Tat Oyi has been characterized in preclinical models. A clinical trial phase I/II has been started for a therapeutic Tat Oyi vaccine application: In a double blind study, forty eight HIV seropositive were divided in four groups (twelve patients per group) received three consecutive injections of a candidate vaccine composed of 0 (group 1 control placebo), 10 (group 2), 33 (group 3) and 100 μg (group 4) of synthetic Tat Oyi. In each case, the three injections were intradermal and achieved monthly (i.e. M0, M1 and M2). Results: Preclinical studies have demonstrated the potency of Tat Oyi vaccination to generated neutralizing antibodies against conformational epitopes not found in other Tat vaccine candidates. Further more, a vaccination assay with Tat Oyi in a macaque model showed that injected animals had lower viremia levels after heterologous mucosal challenge with SHIV, moreover the virus-infected reservoir cells disappeared with time in the vaccine group. In clinical Phase I trial, the vaccine candidate with Tat Oyi proved to be safe and well tolerated. Conclusions: The specific feature of this vaccine candidate versus other Tat based vaccine candidates relies on Tat 3D conformation and the ability to induce a cross reactive immune response to Tat variants, active against this extracellular HIV target. Biosantech’s vaccine candidate therapeutic effect will be analyzed by measuring the immune response and HIV replication after stopping HAART for 2 months in the ongoing Phase IIa trial.
Arangassery Rosemary Bastian
Drexel University College of Medicine, USA
Title: Mechanism of multivalent nanoparticle encounter with HIV-1 for potency enhancement of peptide triazole virus inactivation
Time : 12:00-12:25
Biography:
Arangassery Rosemary Bastian was born in Kerala in India, before moving to Kenya with her family at the age of three. In 2006, Arangassery enrolled to study Biomedical Engineering at the Manipal Institute of Technology in India, doing her final year in a partnership programme with Drexel University in Philadelphia, where she graduated with a Bachelor of Science degree in 2009. She is currently studying for there for PhD.
Abstract:
Introduction: Initial entry of HIV-1 into host cells remains a compelling and yet elusive target for developing agents to prevent infection. This step is mediated by a sequence of interactions of a trimeric gp120/gp41 envelope (Env) protein complex with host cells, including initial gp120 encounter with the cellular receptor CD4 and a chemokine co-receptor usually either CCR5 or CXCR4. A peptide triazole class of entry inhibitor leads has been shown to bind to gp120 with close to nanomolar affinity, to suppress protein ligand interactions of the Env protein at both its CD4 and co-receptor binding sites and to inhibit cell infection by a broad range of virus subtypes. Further we have also shown that gold nanoparticle conjugated peptide triazoles lead to 20 fold enhanced potency of their anti-viral effects against HIV-1. Previously bowman et al. has shown that multivalent display of HIV inhibitors on gold nanoparticles (AuNPs) has lead to a substantial amount of poency enhancement. This study will lead to the study of size dependency and density dependency on the gold nanoparticle peptide triazole conjugates to further understanding of their mechanism of action leading to enhanced potency. Materials and Methods: The AuNPs were synthesized using a modified citrate reduction method to obtain size-controlled, stable and monodisperse AuNPs. The peptide (KR13) was conjugated to the AuNP using a direct gold-thiol covalent link. The size and extent of polydispersity of the AuNP-KR13 conjugates were measured using Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). The HIV-1 viral entry inhibition potencies of KR13 and AuNP-KR13 conjugates were compared using a single-round pseudoviral infection luciferase reporter assay using lab synthesized pseudoviruses. We subsequently tested the effects of KR13 and AuNP-KR13 on the virus particle itself by measuring release of the nucleocapsid protein p24 using ELISA analysis of cell-free virion inhibition. Results and Discussion: Compared to peptide triazole alone, the 20 nm AuNP-KR13 conjugate exhibited a close to 20-orders of magnitude enhancement of infection inhibition activity (Table) and further with increasing size of AuNP, the potency was enhanced further with the 120 nm AuNP-KR13 having nearly 1600 fold enhancement (Table). KR13 and AuNP-KR13 conjugates are specific for HIV-1 envelope. There was no significant in vitro cytotoxicity observed for either KR13 or AuNPKR13 conjugates. Further the residual virion that was generated upon treatment with KR13 was immunoreactive while the residual virion generated upon AuNP-KR13 treatment was completely inactive. The mechanism was studied by observing the morphological changes caused by both KR13 and AuNP-KR13 on the HIV-1 virion using TEM. Conclusions: In summary, we report the ability of modified peptide triazole inhibitors that target HIV-1 gp120 to physically disrupt virus particles in the absence of host cells. At conditions similar to those at which both KR13 and AuNP-KR13 conjugates inhibited HIV-1 BaLpseudovirus infection of HOS.T4.R5 cells, it also caused release of HIV-1 gag p24 when incubated with virus alone. Both inhibition of cell infection and p24 release were enhanced substantially by increasing diameter of the multivalent display of KR13 on gold nanoparticles. The mechanism of action of AuNP-KR13 is evidently different from KR13 leading to cell free virus transformation leading to further insights towards virus-cell fusion mechanisms.
Ekwu B B Ochigbo
Stellenbosch University, South Africa
Title: Adherence to PMTCT antiretroviral therapy among HIV infected pregnant women in Area W Clinic, Francistown Botswana
Time : 12:25-12:50
Biography:
Ekwu B B Ochigbo is a Registered Pharmacist and a HIV & AIDS resource person. He holds an MPhil with distinction in HIV & AIDS Management from the Africa Centre for HIV & AIDS Management, Stellenbosch University, Cape Town, South Africa. He is also the Director of TibePharmacare, a pharmaceutical and health research consultancy close corporation. His interests are in therapeutics and treatment outcomes research.
Abstract:
The purpose of this research was to determine the level of adherence among HIV infected pregnant women on prevention of mother to child transmission (PMTCT) antiretroviral therapy, and to establish the factors that contribute to poor adherence and their relative importance, in order to suggest intervention strategies that will improve treatment adherence among this population. The study was conducted in Area W Clinic, Francistown Botswana, and was a prospective cross sectional study using semi-structured questionnaire, and data collection form. In total, 61 pregnant women participated in the study and were all within three to nine months gestation, and had been enrolled into the PMTCT program at least more than one month previously. The following were their characteristics: 75% were within the ages of 26 to 42 years old, 90% were single, 81% had attained secondary school education, and 60% were unemployed. Adherence was considered optimum if greater than or equal to 95%. The participants demonstrated a good knowledge of the importance of PMTCT treatment adherence. Reported optimum adherence levels were 84% by virtual analogue assessment, and 82% by pill count. Ninety eight percent of participants reported they did not miss any dose during the last three days before the interview. The most important factors influencing adherence from the study were pregnancy related illnesses, medication side effects, and month of pregnancy of the patient as participants tended to adhere less as they got closer to delivery. It is therefore important for care-givers to carefully monitor patients for these effects, and to carry out continuous adherence counselling with special attention given to those approaching delivery in order to improve or maintain overall adherence to PMTCT therapy. In conclusion, adherence levels to PMTCT therapy among the population sampled was high but can be further enhanced with interventions designed to cover and improve the highlighted areas in the implementation of the preventive therapy.
Joan Smith Sonneborn
University of Wyoming, USA
Title: Novel anti-retroviral drug targets: Interfering siRNA and mitochondrial TERT expression
Time : 12:50-13:15
Biography:
Joan Smith-Sonneborn is a Professor Emeritus who completed her PhD at Indiana University, Postdoctoral studies at Brandeis University, and University of California Berkeley. She was working as a Research Associate, University of Wisconsin, Professor at University Wyoming and did sabbatical training at U Southern California Berkeley, and Monash University, Australia. She has 68 articles in reputed journals, over 100 presentations in United States, England, Germany, Monte Carlo, Sicily, Italy, Japan, Malaysia, Canada, Mexico, and Argentina. She is presently a member of NYAS, GSA, and NSCA. She has served as Chair of the International Ciliate Conference, Gordon Conference, and reviewer for grants, journals, and Advisory Board for FDA.
Abstract:
Telomerase can be touted as the miracle anti-aging enzyme that reverses the age-related attrition of telomere ends. But recent studies reveal a darker side of telomerase related to its role independent of telomere functions in cancer, inherited, and infectious disease states. The catalytic subunit of telomerase, TERT telomerase reverse transcriptase, is known to function as an RNA dependent DNA polymerase in the nucleus (TERT-TERC), as an RNA dependent RNA polymerase, an RdRP (TERT-RMRP), in mitochondria, and, as TERT alone interacting with master regulators of cell function, and/or protection of mitochondrial DNA. The mitochondrial TERT-RMRP is the only mammalian RdRP identified to date, capable of generating double stranded RNA, and acting as a substrate for dicers to generate small interfering RNA’s. TERT also shows conservation of the viral close-right-handed polymerase structure, like viral polymerases, and is capable of producing cDNA, double stranded RNA, and small RNA’s capable of controlling mammalian genome expression. TERT also shows promiscuous partnering with RNA elements, RMPR, tRNA, and TERC. TERT, with its versatile viral-like functions, seems like a valuable hostage for use in viral infection. Telomerase is known to increase in retroviral infections, and can increase mitochondrial oxidative stress resistance by inhibition of pro apoptotic genes, a known role of independent of TERT-TERC. Since telomerase is already a target in anti-cancer drugs, the literature provides a valuable reservoir for potential anti-retroviral drugs. Drugs that inhibit the siRNA’s that promote viral survival, or are necessary for viral survival, offer promising potential success in anti-retroviral therapy, such as interfering with the HIV-TAR miRNA, used to establish initial virus survival and replication or allowing release/stimulation of cell immunity processes using hormetic mimetics.
Nwankwo Norbert Ikechukwu
Madonna University, Nigeria
Title: Direct computerized translation of biological data into biological information is now feasible: The gains of digital signal processing-based bioinformatics techniques
Time : 13:15-13:40
Biography:
Norbert Nwankwo is working as an assistant professor in Madonna University which is located in Nigeria
Abstract:
Obtaining biological functionalities such as pharmacological activities, disease processes, physiological and structural properties by analyzing the sequence information attributed to them has preliminarily been considered impracticable. This is because there are no known procedures that could be engaged in order to help uncover biological functionalities encoded in the sequence information. It has also been recognized that most biological functionalities of drugs consisting of alkaloids, flavonoids, Terpenes, steroids, etc could be expressed in one gene/protein or the other. For example, Multidrug-resistance transporter gene (MDR1) encoding genes for P-glycoprotein and CYP450, which play vital roles transport and metabolism of Antiretroviral agents have been identified. This MDR1 gene regulates the activity of some antiretroviral drugs. Similarly, anti-bacteria multi-drug resistance genes (MDR1 and MDR2) control the activities of Ciproxfloxacin (an alkaloid), Penicillin (a Beta-lactamase) and tetracycline (a polyketide), Gentamycin (an Aminoglycoside) antibiotics, etc. The same applies to anti-Malaria agents and others. In effect, activities of a wide range of therapeutic agents belonging to numerous groups could be read from one gene/protein they express. Furthermore, genes/proteins encoding therapeutic agents can provide as much information as the therapeutic agents. Direct translations of sequence information into biological functionalities were truly impossible until 1985 when researchers saw proteins/peptides as signals (numerical sequences) instead of piece of fish, meat, bowl of beans or an enzyme. This has opened up a novel area of research. As signals, proteins and peptides were analyzed using techniques that have help develop technologies like Radar, Image Processing and Speech Detector. This technique is called Digital Signal Processing (DSP). This presentation demonstrates how biological functionalities could be translated directly from their sequence information using a DSP technique called Informational Spectrum Method (ISM) and two peptides VIPMFSALS and CAPAGFAIL. This technique has offered direct translation of sequence information into various bio-functionalities. It compared the efficacy of two anti-retroviral agents (Enfurvitude and Sifurvitude) as well as two starter materials (P18 and P32) for the designing of anti-malaria vaccines. It explained the HIV progression to AIDS. It identified the origins of HIV-1 non B subtypes that infected American soldiers on Foreign Service. It elucidated the molecular mechanisms to protection offered to the heart by Influenza vaccines as well as Emilins to Anthrax antigen. It calculated biological functionalities and has helped develop a biomedical device, Computer-Aided Drug Resistance Calculator. Based on the level of biological functionalities uncovered from sequence information using DSP procedures, it can be ascertained that it has now become feasible to obtain same results we get from clinical laboratories by analyzing sequence information involved. Because this approach is rational, it is recommended that it be fully exploited.
Namita Kumari
Center for Sickle Cell Disease, Howard University, Washington,U.S.A
Title: Heme Inhibits HIV-1 Through the Induction of Heme Oxygenase 1, Ferroportin, IKBα and p21
Time : 14:15-14:40
Biography:
Namita Kumari is a researcher at Center for Sickle Cell Disease Howard University which is located in USA
Abstract:
Hemin inhibits HIV-1 infection in cultured macrophages and T-cells and also in HIV-1 infected humanized mice by inducing heme oxygenase -1 (HO-1) via a protein kinase C-dependent pathway (reviewed in [1]). HO-1 expression in LPS-treated human macrophages protects them against HIV-1 infection in part through production of MIP1α, MIP1β and LD78β chemokines that decrease CCR5 expression. Iron depletion by iron chelators or through the expression of ferroportin, an iron export protein, inhibited HIV-1 [2, 3]. Here, we show that in heme-treated THP1 cells, mRNA expression of ferroportin, p21, hypoxia-induced factor (HIF)-1α and IKBα, an NF-κB inhibitor was increased and CDK2 expression decreased. HIV-1 replication was also suppressed in THP-1 cells treated with hemin but subsequent treatment with hepcidin restored HIV-1 replication, suggesting that ferroportin played a key role in the HIV-1 inhibition. Stable ferroportin knock-down in THP-1 cells led to the inability of hemin to inhibit HIV-1, further supporting the idea that that ferroportin plays a key role in this process. In addition, hemin treatment reduced the expression of p65 subunit of NF-kB and induced expression of IKBα. Cells treated with hemin were arrested in G1 phase of cell cycle suggesting that expression of p21 and decreased in CDK2 expression affected the cells cycle. Stable HIF-1α knockdown in THP-1 cells increased HIV replication indicating that HIF-1 might also restrict HIV-1 replication. Taken together, our study shows that induction of HIF-1 and iron export pathways might protect hemin-treated THP-1 cells from HIV-1 infection. Additional molecular mechanisms of heme-mediated HIV-1 inhibition might also include NF-kB inhibition by IKBα, reduction of CDK2 epxression and induction of p21 leading to the inhibition of HIV-1 transcription.