Head - Centre for Innate Immunity and Infectious Disease

Deputy Director, Hudson Institute of Medical Research

NHMRC Senior Principal Research Fellow,

"Innate immunity proves promising for fighting disease"

Professor Paul Hertzog believes our innate, or first-line, immune defence system offers great promise in a range of therapeutic areas. As Head of the Centre for Innate Immunity and Infectious Disease, Paul oversees research that aims to increase understanding of how immune cells operate. His facility is also using genome sequencing to find genetic signatures for a variety of diseases.

Innate immunity is our natural ability to provide an immediate defence against infection. Unlike the instructive immunity that vaccination offers against specific viruses, our innate immune system responds in a generic way to provide an immediate defence against pathogens. Paul says they cannot lose sight of the fact that immune responses can sometimes be inadequate or too strong.

'Immune response is always about balance', Paul says. 'Whether you think about innate immunity, inflammation or vaccination, we know if things work well you get a burst of activity and resolve a disease. Depending on the disease, that might take two or three days.

'There's a subtle balance of getting a fast and adequate immune response, both in strength and duration, but not so much that it creates acute disease such as septic shock, or chronic autoimmune disease. We try and understand those balances when we put in a molecule or remove it with therapeutic antibodies.'

Paul's facility recently discovered a new cytokine molecule that regulates immune responses in the female reproductive tract.

'This is a particular type of cytokine called interferons, which are usually produced in response to a particular stress like an infection. They act locally if you get an infection by recruiting immune cells to the site of damage. They also get into the bloodstream and go to your major lymphoid organs such as your spleen or bone marrow. They can stop cells growing or modulate whether cells die or not. Cytokines have been used against cancers, hepatitis and autoimmune diseases like multiple sclerosis.

'Our recent discovery is being prepared for publication and we've taken out patents because we think it might have some translational benefits. It's going to be relevant to a lot of STIs, like chlamydia, herpes, HIV and papillomavirus. We think our discovery will help treat those diseases, maybe detect them and formulate new vaccines. It might also be usable against gynaecological cancers and endometriosis,' Paul says.

Another of Paul's interests incorporates the complex area of bioinformatics to understand how genes in the genome interact. This allows his facility to find genetic signatures for diseases, and they're currently involved in exciting studies on infections and cancers.

'Current technologies enable us to examine how a cell responds by measuring the output of the genome. Fifteen years ago we could measure one gene at a time, whereas now we can measure all 30,000 and look at how they've changed.

'When we study innate immune responses, whether they are infections or cancers, we aim to look for signatures. We no longer look for a single marker, but groups of markers. It's a simple indicator for some diseases, such as diabetes, but it's more complicated for cancer and infections.