A key aspect of how the body kicks the immune system into action against tuberculosis is revealed in research published today.
The authors, writing in Science, hope that their research could aid the development of novel vaccines and immunotherapies to combat TB, which is responsible for two million deaths each year.
The cause of TB is a slow-growing bacterium known as Mycobacterium tuberculosis. Scientists have known for some time that when host cells are invaded by this bacterium, the host cells are able to call up additional immune cells such as lymphocytes to fight them and try to limit the damage which the bacteria can cause.
The new research, by scientists from Imperial College London, the Universities of Cambridge and Oxford, and other international institutions, identifies a receptor on the host cells which triggers the immune cells' response to tuberculosis. The scientists demonstrated that without this receptor, known as CCR5, mycobacteria were able to thrive inside host cells, as the immune cells did not receive the signal from CCR5 to attack them.
The scientists hope that their findings could enable a novel vaccine or immunotherapy to be developed which could artificially kick the immune cells into action in the same way as CCR5. This could boost the immune response to TB.
Both types of interventions are urgently required, since the BCG vaccine does not offer optimal protection and the current treatment regimens for tuberculosis require at least 6 months medication. This encourages the development of multi-drug resistant strains, as patients often do not complete the full course of treatment.