The activities of the HIV Immunovirology Lab can be divided into three categories.

• A substantial proportion of laboratory-based activity is directed towards providing routine or semi-routine laboratory support essential for the successful conduct of clinical trials and epidemiological studies conducted by clinical trials groups at St Vincent’s Centre for Applied Medical Research (SCAMR) and the National Center in HIV Epidemiology and Clinical Research (NCHECR), through specimen processing and conduct of specialised immunological and virological assays. These include immunogenicity assays for vaccine trials.

• The second component is the conduct of clinical trials and natural history studies in pathogenically informative populations of patients with HIV-infection such as those identified with primary infection and long term non-progressors.

• Finally, senior scientists and academics within the Program are responsible for their own research projects on pathogenesis and development of therapeutics.

Immunopathogenesis work currently relates to CD4 T-cell function in early HIV infection and in natural controllers of the disease. Novel methodologies for the characterisation of antigen-specific T-cells and T regulatory cell have been established allowing the functional and molecular characterisation of these difficult to study cells. These novel methodologies have substantial implications for the understanding of the immunopathogenesis of a range of infections apart from HIV infection, including Hepatitis C and autoimmune diseases such as celiac disease. It has also allowed us to gain insights into the location of reservoirs of HIV infections.

The effect of early therapeutic intervention with integrase inhibitors and other anti-retroviral regimens on these reservoirs is one of the major current focuses within the laboratory.  

We have also described a novel way of knocking down HIV replication using promoter targeted siRNAs which induce transcriptional gene silencing. This novel approach induces prolonged and profound suppression of viral replication by inducing a repressive chromatin structure in the integrated forms of both HIV-1 and SIV. Current efforts in this project focus on assessing effective delivery systems for these constructs and understanding the mechanisms underlying the induction and maintenance of this state that is similar to viral latency.

The HIV Immunovirology Lab works collaboratively with the National Centre in HIV Epidemiology and Clinical Research, the St Vincent’s NSW HIV Reference laboratory and a number of Australian and international groups both in the first world with current productive collaborations with groups based in the North America, UK and Japan, and with groups in the developing world, particularly in Thailand.

The HIV Immunovirology Lab is located in a purpose built facility on the St Vincent’s Research Campus. Its facilities include a state of the art PC3 laboratory. The group has the capacity to perform advanced multi-parameter flow cytometry, and to safely perform biologically contained multi-parameter cell sorting. This allows the functional and molecular characterisation of lymphocyte populations. The laboratory is well equipped for both cellular and molecular work. The access to material from both natural history studies and clinical trials conducted means that much of this work is conducted on clinically relevant material. The group has successfully trained and mentored a large number of PhD and honours students.

Professor Anthony Kelleher heads the HIV Immunovirology Laboratory.  There are currently four senior scientists and five research assistants, as well as three full time employees who specifically work in specimen processing for clinical trials and two clinical project coordinators. Presently four students are undertaking PhD programs and two students are undertaking honours year projects, under the guidance of Professor Kelleher and other senior staff within the program.

The HIV Immunovirology Laboratory is supported though competitive grants from a range of granting bodies including The National Health and Medical Research Council (NHMRC).

HIV Immunovirology Research Laboratory Trials Group

The HIV Immunovirology Research Laboratory Trials Group is responsible for the management of a large cryogenic repository. Vials in this repository are from HIV related pharmaceutical trials and natural history studies. The group undertakes specimen processing, storage, local and international shipping and database management. Trials staff also provide core laboratory support for researchers within the HIV Immunovirology Research Team.

Virology

HIV Reservoirs

Our team is working on the challenge of HIV persistence and latent reservoirs, using a translational science approach in collaboration with the clinical laboratory research groups. We are interested in the underlying pathogenesis of persistent HIV infection, focusing on specific subsets of CD4 T cells (immune cells that are infected by HIV) that are important for the establishment and maintenance of HIV persistence. Our techniques involve the application of sensitive molecular assays for the quantitation of RNA and DNA in patient samples from diverse clinical settings. Another important aspect of our work is to evaluate new treatment strategies that are aimed at reducing the size of the latent HIV reservoir that persists despite treatment.

Transcriptional silencing by siRNAs

Our current research interest is based on Non-coding RNA regulation to control gene expression, in particular, short interfering RNAs (siRNA) and micro RNAs (miRNA). Our interest is to investigate the pathway that siRNA uses to interfere with transcription via the promoter DNA to induce heterochromatin formation (closed chromatin structure).  The siRNAs have succeeded in inducing HIV-1 and SIV gene silencing in vitro.  Our recent findings in studies of HIV-1 infected individuals reveal that miRNAs, are associated with progression of HIV-1 infection.  This suggests that certain miRNAs may contribute to the regulation of HV-1. Our focus is on extending these exciting observations.

Immunology

Dr Nabila Seddiki research focuses on the cellular and molecular characterisation of T cell subsets, especially regulatory T-cells (Treg), in viral infections (mainly HIV), in the context of vaccine design. Her expertise has allowed the development of new methodologies to identify and isolate antigen-specific Tregs and effector CD4+ T-cells. This assay which has been recently patented, is currently being used in different areas of research in human immunology including autoimmune diseases such as celiac disease and viral diseases such as HIV and Hepatitis C infection.

John Zaunders’ research interests are centred on the effect of HIV infection on CD4+ and CD8+ T lymphocytes, particularly during the acute phase of the infection. To determine the effect of HIV infection, it also requires a comprehensive understanding of the normal processes of activation and homeostasis of T lymphocytes. Therefore, we undertake detailed studies of subsets of CD4+ and CD8+ T lymphocytes using flow cytometry and cell sorting. We have identified a number of previously undescribed changes as a result of HIV infection, and have developed novel techniques to study the relevant cells, including activated effector cells, Tregs, antigen-specific CD4 T cells and cytotoxic CD4 T cells.

VHCRP Molecular Virology Laboratory projects

The Viral Hepatitis Clinical Research Program (VHCRP) focuses on therapeutic research, including clinical trials, epidemiology and immunovirology. Of particular interest to the program is the natural history of newly acquired Hepatitis C (HCV) and treatment of acute and chronic HCV particularly in the setting of injection drug use. The HCV molecular virology laboratory aims to provide a centralised patient sample repository and assays to assist translational research in collaboration with national and international laboratories.  The laboratory has a strong interest in HCV mixed infections, HIV/HCV coinfection transmission networks, viral resistance and pharmacogenetics.