Colony stimulating factors (CSFs) are proteins that stimulate production of immune (white blood) cells and provide life-saving protection against infection.

WEHI researchers discovered CSFs and pioneered their use as treatments that have improved the lives of millions of people worldwide.

What are colony stimulating factors?

CSFs are hormone-like proteins that stimulate the production of infection-fighting immune cells. Many different cells in our body produce CSFs, which can travel throughout the body and bind to cells with specific receptors for that CSF.

There are four CSFs, called G-CSF, GM-CSF, M-CSF and IL-3. Each CSF has different effects within our body, stimulating different cell types.

Because CSFs can stimulate the production of immune cells, they are used as medicines to boost the production of white blood cells. This can be a vital therapy for people whose immune system has been depleted by chemotherapy or certain immunodeficiency diseases. CSFs are also important medicines used during blood stem cell transplantation.

CSFs research at WEHI

CSFs were discovered by Professor Don Metcalf and his team at WEHI. Professor Metcalf saw the potential of CSFs as a treatment for people with depleted immune systems, and WEHI scientists and their collaborators pioneered the use of CSFs in the clinic.

CSFs were first discovered in the 1960s, but their purification and development as therapies took several decades and collaboration between hundreds of researchers at WEHI and around the world, using the latest technologies of their time.

Professor Metcalf led pre-clinical testing of CSFs as drugs, leading to the world’s first clinical trials of G-CSF and GM-CSF in the late 1980s, a collaboration between WEHI, the Ludwig Institute The Royal Melbourne Hospital and pharmaceutical companies. These trials showed injections of CSFs were an effective supportive therapy for cancer patients, and they were approved for clinical use in 1991. WEHI research also led to the use of CSFs to enhance blood stem cell transplantation, revolutionising curative stem cell transplants for people with life-threatening blood cancers. CSFs have been used to treat many millions of patients around the world.

WEHI researchers also discovered a ‘dark’ side of CSFs made naturally in some people – they can drive disease-causing inflammation in conditions such as rheumatoid arthritis. Preclinical research at WEHI showed that reducing CSF signalling could dampen down this inflammation. Medicines that reduce CSF signalling are now in clinical trials for conditions such as rheumatoid arthritis.

Sixty years since CSFs were discovered at WEHI, our scientists continue to investigate these critical proteins. We have uncovered many molecular details of how CSFs signal between cells, and the role of CSFs in a range of normal and diseased cell behaviours. The discoveries made and technologies developed in CSFs research have also underpinned research breakthroughs about other cell signalling systems and diseases.