Researcher processing dendritic cells in a 'clean room'.

Burnet’s researchers are discovering new ways to target the ‘right’ dendritic cells (DCs) to evoke an immune response against cancer, creating new optimism about future cancer vaccine development.

Dendritic cells are often referred to as the ‘sentinel guards’ of our immune system but are rare and difficult to isolate. Until recently, understanding was limited about their function and subsets.

Head of Burnet’s Bio-Organic and Medicinal Chemistry Laboratory, Professor Geoff Pietersz and his team are finding ways to use dendritic cells (DCs) to evoke an immune response against cancer.

“The key strategy involves using a ‘carrier’ to deliver tumour-associated proteins to DCs, so they activate an immune response to target and destroy the cancer cells,” he said.

Discover more about the exciting dendritic cell research being undertaken in our Centre for Immunology laboratories by Professor Pietersz, Dr Meredith O’Keeffe, Dr Irina Caminschi and Dr Mireille Lahoud in the Autumn 2012 edition of IMPACT.

A vaccine (CVac™) based on mannan developed by Professor Pietersz and colleagues at the Austin Research Institute (which merged with Burnet in 2006) has shown promising results in clinical trials, and is now in development by Prima Biomed Ltd as a vaccine for ovarian cancer. The vaccine uses cells harvested from the patient, which are converted to DC, mixed with the vaccine and reintroduced into the patient’s body.

Recently, the Pietersz Laboratory developed a more potent mannan formulation, from which 4G Vaccines Ltd are developing an improved vaccine.

Professor Pietersz believes that while historically there has been much pessimism towards cancer vaccines, the growing knowledge of DC subsets, their function and how cancers and our immune system overcome vaccines, allow for new optimism.

“Greater understanding is helping us identify the ‘right type of DCs’ to target, and to avoid DCs that counteract the generation of effective immunity,” he said.

“In 2010 the first cancer vaccine, Provenge®, was approved by the FDA for use against a type of prostate cancer. This vaccine uses the patient’s own blood cells, including DCs, and demonstrates the significant step forward DC research provides for cancer vaccines.”

Discovery of dendritic cells

More than 35 years ago, Professor Ralph Steinman (Rockefeller University, New York) discovered a new type of cell, which he called ‘Dendritic Cells’. Steinman hypothesised that these cells might hold the key to activating T-cells, an immune cell that helps our bodies develop an immunological memory in what is known as ‘adaptive immunity’. After decades of research, and a Nobel Prize for Steinman’s work in 2011, dendritic cells provide new hope for vaccines and therapies against cancer and a myriad of pathogens.