KILLER T-CELLS: works on mice, why not us?

Linda and her sister Carolyn, 1951

There is an Interesting article in the April 23^rd issue of The New Yorker, entitled “The T-Cell Army”.  It is part history and part reportage; the recent history of novel cancer treatments and what is going on right now.  It is mainly concerned with two directions in cancer therapy research: individually targeted therapies based on the cancer’s genome, and immunotherapy.  Emphasis is on the latter.

Like nearly everything I have learned in the past few months about how cells work, how DNA does its job, what causes cancer, etc., immunotherapy turns out to be vastly more complicated than it ought to be: full employment for herds of biochemists, but frustration for guys like me.  What I thought I knew about the immune system and cancer was that the immune system is programmed to distinguish between “Self” and “Non-Self” and attack only the latter.  As cancer is a piece of Self gone wild, the immune system stands by and watches as it destroys the body.  Well, yes and no.

As part of the immune response the body generates various kinds of cells: neutrophils, macrophages and T-cells (sometimes called Killer T-cells, a name I really like) and, probably lots more; remember that my biology reference books is “the Complete Idiots guide to College Biology”.    Neutrophils and macrophages attack a particle of Non-Self (a virus, for instance) by swallowing it whole and then digesting it at leisure.  Killer T-cells, by contrast, attack from the outside; all guns blazing – firing enzymes.  Unfortunately, T-cells need to be persuaded to attack tumor cells.  It appears that there is a protein (CTLA-4) attached to the surface of the T-cell that must  be neutralized with an antibody before the T-cell will attack a tumor.  Other proteins that need to be mollified or tricked also are mentioned; no doubt the case is more complicated than anyone thinks.  Nevertheless several therapies have been devised, largely by using our friend the mouse, that are proving effective against metastatic melanoma.  The side-effects described are horrible, however; another reason to stay out of tanning beds.

At any rate, the article gives one further reason to hope.  As with most New Yorker essays there are numerous little anecdotal interjections; these serve to lighten the biochemical gloom.  Mostly they are about patients and their (often quite favorable) outcomes.   I recommend that you buy the mag and read the article.  I find with The New Yorker in general that its chief attraction is its cartoons, and that many articles lead one to suspect that the authors are paid by the word.  Not so here.  But, as the stupid magazine will cost you $6.00, maybe go to the library.