10
$\begingroup$

X-posted on reddit AskScience here.

I know that macrophages engulf foreign bodies and transport them to various waste excretion pathways (sorry if the terminology is wrong), and if the foreign bodies are cellular in nature, they get trapped in phagolysosomes and get digested by enzymes.

Does the macrophage get any "nutrition" by destroying the cells, the same way that a person would if those same cells were to pass through their digestive system? Is there any chemical energy produced by the catalysis that the macrophage then uses, e.g. pyruvate for its mitochondria? Or scavenged cellular components that it can use to build its own cytoskeleton?

$\endgroup$
  • 1
    $\begingroup$ Maybe there is a study showing if labeled phosphate of phagocytosed bacteria ending up in the macrophage DNA or mitochondria? I will search for this. $\endgroup$ – WesternBlöd Apr 17 '15 at 12:59
5
$\begingroup$

In this article it is described that starved macrophages 'consume' heat inactivated bacteria through phagocytosis with enhanced ability. Starving can also induce (macro)autophagy and the pathways are connected with phagocytosis,in the macrophages under investigation it was shown that autophagy did not play role in the enhanced ability of phagocytosis. The paper however does not mention anything about macrophages utilizing the resources obtained by the digestion of the bacteria. although it would seem logical. I'll keep looking.

Edit:

I found a text book that says:

in general cells of the macrophage series have two major functions. On f their functions ,as their name ("large eater") implies, is to engulf and, with the aid of all the degradative enzymes in their lysosomal granules, break down trapped materials int ismple amino acids, sugars and other substances, for excretion and reutilization.

Source : IMMUNOLOGY A Short course 3rd edition by Eli Benjamini, Geoffrey Sunshine and Sidney Leskowitz 1996 pages 23-24. ISBN 0-471-59791-0. I only have printed copy, but I'll try to find online version. The other function is antigen presenting.

Thus I can say that yes macrophages and other cells do utilize resources from digested pathogens.

$\endgroup$
5
$\begingroup$

I've found an old paper using radioactively labeled bacteria to track their fate in macrophages. According to the data, both $^{14}$C and $^{32}$P are reutilized in the host cell.

COHN ZA. (1963). The fate of bacteria within phagocytic cells. I. The degradation of isotopically labeled bacteria by polymorphonuclear leucocytes and macrophages. J Exp Med. Jan 1;117:27-42.

$\endgroup$
  • $\begingroup$ It would make sense that nutrients are consumed from the breakdown of the phagocytosed object. Gotta love some of these old papers probing fundamental (yet relatively minor, by today's standards) questions $\endgroup$ – Cantona's Collar Apr 19 '15 at 8:35

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.