skip to main content

Attention:

The NSF Public Access Repository (PAR) system and access will be unavailable from 8:00 PM ET on Friday, March 21 until 8:00 AM ET on Saturday, March 22 due to maintenance. We apologize for the inconvenience.


Search for: All records

Creators/Authors contains: "Mallory, D. Paul"

Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher. Some full text articles may not yet be available without a charge during the embargo (administrative interval).
What is a DOI Number?

Some links on this page may take you to non-federal websites. Their policies may differ from this site.

  1. Phagocytosis is a critical immune function for infection control and tissue homeostasis. During phagocytosis, pathogens are internalized and degraded in phagolysosomes. For pathogens that evade immune degradation, the prevailing view is that virulence factors are required to disrupt the biogenesis of phagolysosomes. In contrast, we present here that physical forces from motile pathogens during cell entry divert them away from the canonical degradative pathway. This altered fate begins with the force-induced remodeling of the phagocytic synapse formation. We used the parasiteToxoplasma gondiias a model because liveToxoplasmaactively invades host cells using gliding motility. To differentiate the effects of physical forces from virulence factors in phagocytosis, we employed magnetic forces to induce propulsive entry of inactivatedToxoplasmainto macrophages. Experiments and computer simulations show that large propulsive forces hinder productive activation of receptors by preventing their spatial segregation from phosphatases at the phagocytic synapse. Consequently, the inactivated parasites are engulfed into vacuoles that fail to mature into degradative units, similar to the live motile parasite’s intracellular pathway. Using yeast cells and opsonized beads, we confirmed that this mechanism is general, not specific to the parasite used. These results reveal new aspects of immune evasion by demonstrating how physical forces during active cell entry, independent of virulence factors, enable pathogens to circumvent phagolysosomal degradation.

     
    more » « less