THE inability to make just one of many immune signalling molecules called
cytokines can render a person vulnerable to infection by bacteria that are
usually harmless.
An international team of researchers studied a child with an inherited gene
defect that prevents production of a cytokine called interleukin-12. The child
has suffered serious infections from types of mycobacteria that normally only
cause illness in people who have severely compromised immune systems (The
Journal of Clinical Investigation, vol 102, p 2035).
The results support earlier evidence that IL-12 is crucial in warding off
mycobacteria, a group that includes the organism that causes tuberculosis. Team
member Jean-Laurent Casanova of the Necker Children’s Hospital in Paris thinks
some people might be more susceptible to TB than others as a result of such gene
defects.
