Populations of viruses in an host can be very diverse and just as the behaviour of a population of humans can be very different to the behaviour of individuals in them, populations of viruses behave differently to the behaviour of individuals in them. This diversity may provide a survival advantage to the virus and it also may regulate the severity of the symptoms in an infected host. This study will provide important new information that will drive vaccine strategies and public health policy.
HIV infection is a dynamic process, in which the host immune response tries to control viral growth and keep up with the rapid evolution of the virus. This project assembles an interdisciplinary team of mathematicians and biologists to use a modelling approach to understand the dynamics of viral infection, viral evolution, and immune control in the infected individual. The insights gained from this project will help in the development of new drug and vaccination strategies.
The diversity of HIV quasispecies within a single AIDS patient is far greater than the global diversity of influeneza annually, highlighting the enormous burden HIV imposes on the immune network. The capacity of HIV-1 to evolve quickly has significantly impaired our effort to produce effective vaccine and long lasting treatment strategy. This project utilizes multidisciplinary approaches to delineate determinants that drives the diversification of HIV-1.
Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This proce ....Title: Structure of hepadnaviral pre-genomic RNA. We aim to study the replication strategy of human hepatitis B virus (HBV), a member of the hepadnavirus family. Hepadnaviruses infect hepatocytes in the liver and are released in high numbers into the bloodstream. Infection is transmitted by blood or sexual contact. Hepadnaviruses cause acute and chronic infection with varying degrees of liver disease. The HBV DNA genome is formed by copying of a viral pre-genome made of RNA, into DNA. This process is called reverse transcription and is performed by the viral polymerase. Reverse transcription occurs within viral nucleocapsids made of core antigen. After formation of the new viral DNA genome, nucleocapsids are enveloped in surface antigen and are released from the cell. It is assumed that 1 copy of HBV pre-genomic RNA is packaged within each viral nucleocapsid. However, members of the retrovirus family that have common evolutionary origins to hepadnaviruses and also replicate via reverse transcription, contain 2 copies of RNA. The human immunodeficiency virus (HIV), the AIDS virus, is a well-studied example. In HIV infection 2 RNA genomes are packaged into each nucleocapsid and form a dimeric RNA genome. The HIV RNA is able to fold into a series of stem loops that promote formation of dimers. During the reverse transcription step in HIV replication, the polymerase switches templates and forms new combined strains of virus. The project aims to determine if 2 copies of pre-genomic RNA are packaged into HBV nucleocapsids. HBV pre-genomic RNA is able to form stem loop structures similar to those in HIV and has the potential to form dimeric RNA. If 2 copies of HBV pre-genomic RNA are packaged this will allow us to redefine the viral replication strategy and to develop a greater understanding of the relationships between hepadnaviruses and retroviruses. The formation of dimers will also provide a mechanism for recombination between HBV strains.Read moreRead less
Meiotic recombination in Neurospora crassa: a model for the process in humans and other multicellular eukaryotes. Genes are shuffled by recombination during meiosis in the sexual cycle of higher organisms. This is best understood in yeast. Our findings show Neurospora recombination differs from yeast recombination. It is more tolerant of sequence mismatch, differs in the relative frequencies of gene conversion and crossing over, has frequently interrupted conversion tracts and has transacting ge ....Meiotic recombination in Neurospora crassa: a model for the process in humans and other multicellular eukaryotes. Genes are shuffled by recombination during meiosis in the sexual cycle of higher organisms. This is best understood in yeast. Our findings show Neurospora recombination differs from yeast recombination. It is more tolerant of sequence mismatch, differs in the relative frequencies of gene conversion and crossing over, has frequently interrupted conversion tracts and has transacting genes controlling recombination hotspot activity. We propose to genetically dissect Neurospora recombination which appears to be a closer model for recombination in humans and other higher eukaryotes, where understanding recombination can assist control of genetic disease, efficient breeding in agriculture and our understanding of evolution.Read moreRead less