The immune system is a teeming mass of interacting cells and complex organic chemicals that enable our bodies to deal with microbes. Immunologists have been toiling away for decades now and their research is, these days, at the level of individual molecular pathways. There are millions of these pathways – the circuit diagrams in an unimaginably complex computer.
One of the less well-known roles of the immune system is to identify and remove faulty, worn out or cancerous body cells. In other words it doesn't just fight off intruders, it declutters the house as well. It is fundamental to the immune system that it must, every day, make millions of judgements about what is ‘self’ and ‘not self’ so that it knows whether or not action is needed. It seems that cells that don’t pass its quality control process become re-classified as no-longer-self and dispatched for recycling.
Research into the molecular mechanisms of this decluttering process is beginning to lead to new medical treatments.
In one recent report, a drug has been used (on a small group of patients) to block a molecule that enables bladder cancer cells to prevent an immune attack. The results are looking promising. The cancer cells disguise themselves as ‘self’ and the immune system ignores them. But the compound whips away the disguise and enables the malignant cells to be identified and destroyed. Treatments based on discoveries like this could eventually replace chemotherapy, which uses cytotoxic chemicals that inevitably damage healthy tissues.
In another study, a potential new treatment for malaria has been discovered and is ready to progress to safety trials in humans.
The malaria parasite makes its home inside healthy red blood cells. A couple of million red blood cells are produced every second by the bone marrow, so an equivalent number of worn out cells must be efficiently destroyed and removed from circulation. After detailed research into the genetics and cellular mechanisms of the parasite and into the way the immune system disposes of blood cells, a compound has been discovered that seems to hasten the disposal of malaria-infected cells and clear the parasite from the blood of mice. This is hopeful news when you consider the toll that malaria takes, particularly on young children.
There is an enormous amount of fundamental research that has brought immunology to this point - mountains of Ph D theses and thousands of careers bent over the laboratory bench. This kind of research is not funded by drug companies and the fact that it is now, finally, beginning to produce treatments highlights the need to maintain public funding for pure science.