Macrophages use a bet-hedging strategy for antimicrobial activity in phagolysosomal acidification

Quigly Dragotakes, Kaitlin M. Stouffer, Man Shun Fu, Yehonatan Sella, Christine Youn, Olivia Insun Yoon, Carlos M. de Leon-Rodriguez, Joudeh B. Freij, Aviv Bergman, Arturo Casadevall

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


Microbial ingestion by a macrophage results in the formation of an acidic phagolysosome but the host cell has no information on the pH susceptibility of the ingested organism. This poses a problem for the macrophage and raises the fundamental question of how the phagocytic cell optimizes the acidification process to prevail. We analyzed the dynamical distribution of phagolysosomal pH in murine and human macrophages that had ingested live or dead Cryptococcus neoformans cells, or inert beads. Phagolysosomal acidification produced a range of pH values that approximated normal distributions, but these differed from normality depending on ingested particle type. Analysis of the increments of pH reduction revealed no forbidden ordinal patterns, implying that the phagosomal acidification process was a stochastic dynamical system. Using simulation modeling, we determined that by stochastically acidifying a phagolysosome to a pH within the observed distribution, macrophages sacrificed a small amount of overall fitness to gain the benefit of reduced variation in fitness. Hence, chance in the final phagosomal pH introduces unpredictability to the outcome of the macrophage-microbe, which implies a bet-hedging strategy that benefits the macrophage. While bet hedging is common in biological systems at the organism level, our results show its use at the organelle and cellular level.

Original languageEnglish (US)
Pages (from-to)3805-3819
Number of pages15
JournalJournal of Clinical Investigation
Issue number7
StatePublished - Jul 1 2020

ASJC Scopus subject areas

  • General Medicine


Dive into the research topics of 'Macrophages use a bet-hedging strategy for antimicrobial activity in phagolysosomal acidification'. Together they form a unique fingerprint.

Cite this