I have happened upone it in last episode of Crash Course A&P. It is at 42 second. Here it goes:
Now, it becomes the business of your cell-mediated response, or cellular immune response. And that is where stuff gets serious. Where (a) cell fights (a) cell.
Tell me please why no article was used before the word cell there.
It’s perfectly normal speech; the zero article is often used in this manner. One oft-seen example is the phrase man against man – which is considered a form of literary conflict – but the expression may be found elsewhere as well:
Any violence on the part of man against man or man against nature was a violation of Thoreau's pantheistic views.
(E. A. Moehle - 1972)
The phrase can be used for other living beings, also, such as in the opening sentence of a 2014 LA Times article:
Across the southeastern United States a battle is raging – ant against ant.
I suppose the fragment could be reworded in a couple ways, and still be grammatical:
But the original has a concise and gritty tone that I think the scriptwriter probably wanted to include.
To omit the article there is a form of generalization. The noun is generic not specific. The reference is to the category or class itself, rather than to an instance thereof.
push comes to shove...
vampire fights werewolf ...
predator becomes prey...
day turns to night ...
neither fish nor fowl...
