Cat and mouse games

摘要

The immune system is intimately involved in how tumours develop. But how do tumours avoid being killed by immune responses? It seems that in some instances they can lull immune cells into a false sense of security. A troubled relationship exists between the immune system and tumours — not unlike that between the cartoon characters Tom and Jerry. Tom's disposition is to catch and devour mice, but he hardly ever succeeds in capturing Jerry, who has just too many tricks up his sleeve. On page 141 of this issue Willimsky and Blankenstein report a novel ploy used by tumours to evade the immune system. It seems that sporadic tumours in mice, against which the immune system initially reacts, nevertheless manage to spread by moulding the immune cells that are most effective against them — the killer T cells — into a state that tolerates them.