The Centre for Virus Research

This Centre for Virus Research (CVR) uses the latest technologies of genomics, molecular and cell biology and protein chemistry to investigate HIV and herpes viruses which infect neurons, epidermal and bone marrow/blood cells.

The Centre's research on the immunology of Herpes simplex virus has assisted in the development of the first partially successful vaccine for genital herpes.

Its researchers have successfully defined two new receptors for HIV on epithelial dendritic cells. These are potential targets for blocking entry of HIV into the body.

Professor Tony Cunningham is the Director of The Centre for Virus Research.

Research Groups

The Centre for Virus Research has the following Research Groups:

Cytomegalovirus Group

Our main area of research is the study of a member of the herpes virus family called human cytomegalovirus (CMV). This virus is very common, with infection rates approaching 90% in some communities. Whilst CMV usually causes mild disease in healthy adults, it is the most common congenitally acquired infection in infants where it is the leading viral cause of neurological defects such as deafness. CMV is also a major concern to AIDS patients and those undergoing immunosuppressive therapies such as bone marrow and solid organ transplant recipients, where very serious, frequently life-threatening disease is common.

Following an initial infection, the virus establishes a life-long latent (ie dormant) infection in the human host. Periodically, CMV can reawaken from its latent state, resulting in the shedding of virus in body secretions, a process that ensures its spread through the population. It is this latent state of infection and the ability to reawaken from it that is the major cause of the serious CMV disease in transplant patients. Unfortunately, CMV latent infection remains very poorly understood.

Our research program aims to work out how the virus functions during latent infection so that drugs and other therapies can be designed to lessen the impact of this life-threatening virus on transplant patients. Examples of current projects include:

1. Examining how human cells are affected when they become latently infected. A technology called "DNA microarray" makes it possible to examine the expression of many thousands of human genes in a single experiment.
2. Identifying which CMV genes are active (ie expressed) during latent infection. Identification of these genes and determination of how they function may have profound implications to our understanding of latency.
3. We recently discovered that the virus can actively hide from our immune system during latency. This has provided valuable information on how the virus is able to remain in the human body. We are now further characterizing this finding in order to develop new approaches to fight virus infection.

Supplementary Microarray Data

The following Microsoft Excel documents contain Supplementary Microarray Data produced by Slobedman et. al., J. Virol. 2004.

• Experiment #1 raw data (.xls, 10,975 Kb)

• Experiment #2 raw data (.xls, 11,021 Kb)

• Experiment #3 raw data (.xls, 10,946 Kb)

• Experiment #4 raw data (.xls, 8,934 Kb)

• Experiment #5 raw data (.xls, 11,045Kb)

• Experiment #6 raw data (.xls, 11,009Kb)

HIV Biology Group

This team aims to improve our understanding of how HIV can spread rapidly between cell types, which are known to be important for HIV transmission. HIV transmission begins as a chain of events that enables a critical infection threshold to be reached. By researching this spread, a greater understanding can be attained with respect to mechanisms of HIV migration and amplification. In doing so strategies designed specifically at breaking any part of the chain of transmission can be used in future scenarios for HIV prevention and/or therapy.

Current studies include:

• Genetic manipulation of HIV vectors to spy on HIV in live cells using fluorescent microscopy.
• Generation of HIV vectors for visualization at the electron microscopy level.
• Generation of fluorescent HIV anti-retrovirals for future methods of HIV detection and in vivo diagnostics.
• Genetically engineering chimeric SIV/HIV clones for studies of HIV transmission and prevention.
• Growing and purifying various clones of HIV to be used in various collaborative studies.
• Testing various combinations of anti-retroviral compounds for use in microbicide strategies.

HIV Molecular Pathogenesis Group

The HIV molecular pathogenesis group’s primary focus is to understand the very early interactions of the HIV virus with host cells of the body predominantly human dendritic cells (DCs). These are the first cells to come into contact with HIV within the genital tract.

In 2006 our group revealed that HIV induces partial maturation of DC and in doing so, the virus may utilise the migratory capacity of DC to gain access to T cells in the lymph nodes. The group continues to investigate the mechanisms by which HIV subverts the maturation of DC and the effect this may have on the initiation of an appropriate immune response.

The global gene changes that HIV induces in dendritic cells continue to be investigated using DNA microarray technology, and investigations are now being broadened to include the effects that HIV has on the proteins regulating the expression of interferons.

Other investigations conducted in the laboratory involve investigating ways to prevent infection of DCs particularly those in skin/genital mucosa. The methods employed include using soluble receptors as decoys binding to the virus as well as direct antagonism of the HIV binding receptors. Preliminary studies indicate that these can be effective inhibitors. The ultimate goal is to reduce or even prevent viral trafficking at a very early stage of infection.

HSV Immunology Group

Herpes Simplex Virus (HSV) causes two common infections, cold sores (HSV-1) and genital herpes (HSV-2). Its infection can sometimes result in encephalitis and neonatal herpes. Genital herpes enhances acquisition up to threefold. A partially effective vaccine candidate has been developed (in part based on our previous work) but is not yet licensed.

The HSV Immunology group is focussed on discovering and developing new vaccine candidates and has also been studying the interaction between HSV and immune cells like dendritic cells (DC) and T lymphocytes.

Dendritic cells (DC) are the most potent antigen presenting cells to stimulate T lymphocytes and classified as myeloid dendritic cells (mDC) and plasmacytoid dendritic cells (pDC). Langerhans cells are another type of DC residing in epidermis, which are presumed to play a primary role in herpes lesions. Such Langerhans cells have been shown to be infected in herpes lesions. How HSV infects these cells in vitro and alters their function is now being studied. pDCs are supposed to be restricted to blood and lymph nodes. However during 2006, the group used confocal microscopy, to identify pDC in the skin of genital herpes lesions but are not infected by HSV-2.

In herpes lesions CD4 lymphocytes are the first to enter and partly control HSV infection, preparing the way for later infiltration by CD8 lymphocytes which clear up the infection. Some peptides in glycoprotein D (gD) of HSV-2 were identified as strong immunostimulatory antigens for CD4 T lymphocytes. Some of these “epitopes” are recognised by CD4 lymphocytes of people infected with HSV-1 as well as HSV-2, providing a rationale for why infection with one of these two viruses can protect against the other. Some of these peptides were conjugated to lipid (in collaboration with Professor David Jackson, University of Melbourne). The immunogenicity of the lipopeptides were improved 2-3 fold. We are currently examining the mechanism of these effects.

Molecular Viral Transport and Assembly Group

The main focus of our research are the two human viruses herpes simplex virus (HSV) and human immunodeficiency virus (HIV).

HIV is a retrovirus that causes acquired immunodeficiency syndrome (AIDS), a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections.

HSV, after an initial, or primary, infection, establishes latency, during which the virus is present in the cell bodies of nerves which innervate the area of original outbreak. During reactivation, virus is produced in the cell and transported outwardly via the nerve cell's axon to the skin. The ability of herpes virus to establish latency leads to the chronic nature of herpes infection; after the initial infection subsides, herpes symptoms may periodically recur in the form of outbreaks of herpetic sores near the site of original infection.

One aim of our group is to determine how HSV and HIV are transported within cells at the molecular level. Recent discoveries have shown how virus transport in cells is dependent on interactions between specific viral proteins and cellular "motor proteins" and how in the case of HSV the virus escapes from nerves to infect skin and cause disease. Such information on viral transport will allow development of inhibitors of this process which may be candidates for use as antivirals for control of recurrent herpes simplex or HIV.

Another aim of our group is to determine how HSV is assembled within cells at the molecular level. Recent work has identified crucial molecular interactions required for viral assembly. Such information on viral assembly will allow development of inhibitors of this process which may be candidates for use as antivirals for control of recurrent herpes simplex.

Retroviral Genetics Group

The Retroviral Genetics Laboratory focuses on several different aspects of HIV pathogenesis. We are working on the innate and adaptive immune factors which are found in untreated HIV+ patients with non-progressive disease.

The main goal of this group is to understand what guides the path to non-progressive HIV disease in a subset of HIV+ individuals and can these natural factors, which provide them protection, find some use as therapeutic agents/vaccines. We are adopting a variety of immunological, virological, proteomic and protein chemistry techniques to identify and characterize these novel factors from patients who have lived with HIV for more than 20 years.

Another aspect of this study is genomics where we are gathering information based on the cell surface markers and whole human genome (>47,000 genes) to understand how HIV guides different stages of HIV disease in different hosts and in different cell types within the same host at the level of manipulating cellular phenotype and human gene machinery.

Other studies in the lab are also directed at understanding HIV infection of the brain in relation to cellular infiltration across the blood brain barrier, HIV recombination, emergence of novel HIV strains, their pathogenesis and their role in subverting human gene machinery in different cell types. The Retroviral Genetics lab also runs services for drug resistance and epidemiologic testing of HIV in Australia.

Varicella Zoster Virus Group

The Varicella zoster virus (VZV) is the virus that causes chicken pox (Varicella), shingles (herpes zoster) and post-herpetic neuralgia (PHN). Chickenpox, which is usually seen in children is a clinical manifestation of primary (i.e. first time) infection with VZV and is highly contagious affecting the majority of the population. After recovery from chickenpox, VZV is not eliminated from the body but rather the virus has the remarkable ability to hide in the body in a dormant (latent) form in localized clusters of nerve cells (ganglia) for the life of the host. However, when conditions are right the virus can reawaken (reactivate) and cause shingles. This usually occurs in older people, and is characterized by a localized rash that can be very painful. The commonest and most widely feared complication of shingles is the severe, debilitating pain, referred to as PHN, that can persist for months or even years after the shingles rash has healed. Currently shingles can not be prevented and there are no suitable treatments for shingles or PHN.

Despite its significant impact on the community, little is known about the molecular basis of VZV infection, due in part, to VZV only infecting humans. To more closely examine the interaction of VZV with host cells, the group has established several models of infection using human cell-types which are targets for infection and are relevant to those that suffer from either Varicella or herpes zoster/PHN because each of these cell types are likely to play different, but essential roles in the disease process. These include human fibroblasts (skin cells), neurons (nerve cells) and specialized immune cells (T cells and dendritic cells).

The group has recently shown that human nerve cells infected with VZV do not undergo programmed cell death (apoptosis). This is an important finding because it suggests the nerve cell damage observed when VZV reawakens from its "silent" state in nerve cells to cause shingles is not due to programmed cell death. Another implication from this observation is that VZV encodes a function to interfere with the death response in human nerve cells, thus providing a possible mechanism by which the virus can establish and maintain its life-long dormant infection. We went on to identify the first VZV encoded anti-apoptotic gene ORF63. To further our understanding of VZV with human nerve cells the group has developed a novel model of VZV infection of intact human explant ganglia. The group has shown for the first time that VZV can infect intact human ganglionic cells and this is a novel way of studying the interaction of this virus with human nerve cells.

These features of intact ganglionic infection can now be studied in further detail to better define the molecular mechanisms that underlie VZV infection of ganglionic cells. For example, this model provides a means to rapidly test viral gene mutant viruses and new candidate vaccine strains containing targeted gene disruptions to define viral genes that may play critical roles in VZV neurotropism and to examine in detail the outcome of infection of both neurons and non-neuronal cells with respect to apoptosis and cell function.