The sinseh (physicians) of old had discovered by chance that if they inhaled dried powder prepared from the crusts of smallpox lesions, they were likely to be protected from the killer bug.

The ancient Greeks, too, learned that plague patients could be cared for by individuals who had recovered from the disease and, thus, had gained an 'immune' status.

Immunology is the study and application of the immune system.

Modern immunology has its roots in infectious disease and began with French microbiologist Louis Pasteur and his germ theory of diseases in 1860, which proposed that micro-organisms are the cause of infectious diseases.

We now know that the immune system is involved in more than just fighting off invading pathogens.

Abnormal development or dysfunction of the immune system could lead to human ailments as diverse as leukaemia and lymphoma - which are cancers of the immune system - and conditions such as allergies, asthma, immunodeficiency, intestinal inflammation and the skin disorder, psoriasis.

It has also been linked to auto-immunity such as lupus, where the body's defences attack its own tissues, and to Type 1 diabetes, where immune cells destroy the pancreas.

Why is immunology important to Singapore?

It is one biomedical science discipline that will have a direct impact on the lives of Singaporeans.

It will lead to better treatments and speedier cures.

Fighting disease

OUR little red dot faces the threat of emerging and re-emerging diseases. Singapore has an open border and its population is thus vulnerable to introduced diseases. The 2003 Sars outbreak is one example.

The H5N1 avian flu virus still persists - it is endemic to the region - and could mutate into a form easily transmitted to humans.

Over the past fortnight, Singaporeans learnt of another new virus - chikungunya - which struck home for the first time.

And let's not forget our continuing battle with dengue fever, as well as the threat of malaria and drug-resistant tuberculosis, which are rife in the region.

While immunology research is not equivalent to infectious disease research, it can contribute to treatment by examining the host's responses to pathogens and aid in the development of vaccines for the prevention of diseases.

Combating cancer

ALTHOUGH cancer is a heterogeneous disease that could involve many different cell types, abnormal development of immune cells can give rise to leukaemia and lymphomas such as Non-Hodgkin's lymphoma, chronic myelogeneous leukaemia and chronic lymphocytic leukaemia.

Immunology research can help our doctors understand how immune cells could become cancerous, how other tumour types evade the immune system that is supposed to protect us from them and how we can harness the immune system to combat cancer and, in the process, develop a cancer vaccine.

Recently, Dr Toh Han Chong of the National Cancer Centre demonstrated how immunotherapy could be a weapon in the war against cancer: Immune cells harvested from patients could be 'trained' to become anti-cancer warriors in the lab, then sent back into the patients' bodies to reject advanced forms of the tumour.

Singaporeans are also familiar with autoimmune diseases. The incidence of lupus - a chronic, inflammatory, connective tissue disease that can affect the joints and many organs - is high in our Asian population.

It is estimated that lupus is twice as frequent in Orientals compared to Caucasians.

Studies published in this week's issue of Nature Genetics and the New England Journal of Medicine indicated that among the genes which make a person more susceptible to lupus are those which spell out the code for activating B cells.

These small white blood cells are crucial to the immune defences.

Preparing for payoff

SINCE 2000, Singapore has embarked on an initiative to make the biomedical sciences one of the key engines of the nation's economic growth.

Products of the immune system and those that regulate the immune system have direct economic and commercial relevance as they contribute towards many of today's treatments for human ailments.

There is a huge market for vaccines against infectious pathogens. Affluent societies will also pay for the availability of protective cancer vaccines.

A class of immune product known as cytokine is now being used in clinics.

Leukine or Sargramostin, which is a trade name for the cytokine GM-CSF (granulocyte/ macrophage colony stimulating factor), is used to increase the production of blood cells following chemotherapy or bone marrow transplantation.

Antibodies and cytokines are by themselves also a multibillion- dollar industry as they are frequently used as reagents in diagnostic kits and as tools in R&D laboratories.

Recognising the potential of this discipline, the Agency for Science, Technology and Research (A*Star) set up the Singapore Immunology Network (SIgN) in 2006 to expand the pool of immunology experts in the country.

It will actively seek collaborations with universities, hospitals and other A*Star research institutes.

In cancer research, SIgN's cancer immunotherapy programme will complement the strong basic research capabilities in the Institute of Molecular and Cell Biology and universities, and the excellent clinical capabilities found in the National University Hospital and National Cancer Centre, providing a bridge between basic cancer research and clinical oncology.

Similarly, SIgN's research in autoimmune disorders will fit in with the strong clinical focus on lupus in NUH and Singapore General Hospital.

In addition, SIgN's infectious disease research programme will add to the expertise found in hospitals, the Novartis Institute of Tropical Diseases here, the Duke-NUS Medical School and the Communicable Disease Centre.

Likewise, SIgN will utilise the technological platforms developed by the Genome Institute of Singapore, and hopefully contribute to the development of new instrumentation at the Institute of Bioengineering and Nanotechnology.

Potential new drugs developed by SIgN scientists could then be scaled up for production by the Bioprocessing Technology Institute and used in clinical trials by doctors at the Singapore Institute of Clinical Sciences.

As SIgN's research programmes have direct relevance to clinical sciences, they will serve as magnets to attract medical doctors to laboratory research, and help them gain a mechanistic understanding of diseases and host immune responses.

Similarly, the translational nature of SIgN's research will nudge basic scientists towards research topics that have closer applications in the clinics.

Thus SIgN can be a focal point for medical doctors and basic scientists to interact and learn from each other in a side-by-side effort to seek solutions to human ailments.

Finally, SIgN's emphasis on human immunology and disease-oriented approaches could draw considerable interest from pharmaceutical and biotechnology companies eager to develop the next generation of vaccines and antibody- or cytokine-based drugs.

The writer is the executive director of A*Star's Singapore Immunology Network.