Overview

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photo of Professor Stephen Kent

Head of Unit

Professor Stephen Kent
E: skent@unimelb.edu.au
Location: Level 7, Rm 7064, Peter Doherty Institute for Infection & Immunity, Parkville
W: Personal web page

photo Kent lab personnel enjoying a night out Kent Laboratory personnel at a recent dinner celebrating passing the milestone of 200 publications

An HIV vaccine is urgently needed. The Kent lab is working towards this goal. Our dedicated staff and students drive innovation and new thinking in ways to tackle the HIV/AIDS epidemic. Prof Kent was recently awarded the Peter Doherty Award for Outstanding PhD Supervision which reflects the quality of our work and PhD students in this area.

The HIV pandemic continues to expand rapidly around the world, notably in the Asian-Pacific and Africa. Public health and economic burdens of HIV represents a major threat to regional and global security. Preventative strategies remain limited, and therapeutic options are restricted in both efficacy and implementation. The lack of an effective HIV vaccine is a catastrophic failure of our public health response to the epidemic.

Better strategies are needed to prevent HIV infection and disease. This requires an understanding of how HIV causes AIDS, including which immune responses control HIV replication and which contribute to disease. A better understanding of effective immunity will expand the pipeline to novel treatment and prevention strategies.

Despite the clear need, development of HIV-1 vaccines has proceeded for 20+ years without success. HIV has a propensity to mutate to avoid immune responses and form latent reservoirs - these are formidable challenges to developing successful vaccines. There is a palpable sense in the HIV vaccine research community that fresh innovative ideas are needed. Quantum leaps away from existing paradigms will be needed to make large inroads into defining protective immunity to HIV-1.

To further understand how immune responses can control HIV, we have a series of projects involved in developing new assays to measure immunity and the effect these immune responses have on the virus. We have recently developed a new and exciting technique to measure antibody dependent cellular cytotoxicity (ADCC). We developed a very simple assay on small volumes of blood to measure ADCC responses and are now studying how useful it is in people with HIV and whether it forces the virus to mutate to escape this potentially important response. Although T cell immunity is effective against the virus, immune escape is a hallmark of effective T cell immunity. We have developed innovative techniques to measure immune escape variants very sensitively. This allows us to study the impact of these escape mutants and whether it can force the virus into a weakened state. We have become very interested in how immune responses target the envelope protein of the virus. Surprisingly, our data to date suggests that envelope specific T cell immunity has little impact on virus replication. We are now trying to understand how neutralising antibodies and T cell immunity against envelope could help corner the virus. We also have ongoing projects studying small but important lymphocyte populations such as regulatory T cells and NKT cells . We have recently branched out into adapting some of our novel ADCC assays to understand how ADCC immunity controls influenza pandemics.

Our understanding of immune responses against the virus allows us to push on with developing novel vaccine technologies. In particular we have an exciting project studying nanoparticle vaccines where tiny capsules are loaded with vaccine antigens to protect them from degradation and target important immune cells that stimulate effective immunity. We are continuing to study aspects of overlapping peptide pulsed autologous cells (OPAL) as an effective therapeutic vaccine. We recently showed that this vaccine can delay AIDS. In addition we have exciting projects studying influenza recombinant vaccines. These flexible vaccine technologies allow us to refine our understanding of what will constitute effective immunity to HIV.