Phagolysosome pH

The phagolysosome is a specialized intracellular organelle generated by fusion of the phagosome (engulfed pathogen/particle-containing vesicle) with the lysosome. Its internal pH becomes highly acidic (typically pH 4.5-5.5) due to proton pumping by V-ATPase complexes, which is essential for activating digestive enzymes (hydrolases) and for optimal antimicrobial activity. Acidification enables enzymatic degradation of pathogens and cell debris, hydrolytic breakdown of proteins, and sometimes acts directly as an antimicrobial trigger. Proper regulation of phagolysosome pH is necessary for effective innate immune responses, antigen processing, and presentation, while certain pathogens manipulate or adapt to phagolysosomal pH for intracellular survival. Drugs do not directly target phagolysosome pH, but its alteration can be instrumental in studying cell-autonomous immunity and pathogen-host interactions.

Other names

Phagosomal pHPhagolysosomal pH

if drugs were to target this, it would be by modulating proton pump activity, e.g. V-ATPase inhibition