Volume 34, Number 15 · October 8, 1987
Department of Defense
By M.F. Perutz
The Thorn in the Starfish: How the Human Immune System Works
by Robert S. Desowitz
Norton, 270 pp., $16.95
The great geneticist Theodosius Dobzhansky wrote that in nature nothing makes sense unless we bear in mind that natural selection reigns supreme. In Africa, one of the sources of poverty is a cattle disease caused by a parasite, the trypanosome. The disease is transmitted by the tsetse fly. When this fly stings a cow, the trypanosomes penetrate into her blood, where they are recognized as foreign invaders by some of her white blood cells. Alarmed by that signal, these particular white cells divide and multiply, and their descendants secrete antibodies into the blood that kill the parasites. Alas, not quite all of them. A few survive because genetic mutations have dressed them up in new coats unrecognized by the cow's antibodies; these survivors now divide and multiply, and force the cow's immune system to begin the fight all over again. The same battle repeats itself every few weeks.
Review, 3902 words
To read the full text of this piece, please choose one of the following options:
|
If you are already a subscriber to the Review's electronic edition, please sign in: |
To subscribe to the electronic edition, please press the button below. |
To purchase access to this article for $3, please press the button below. |