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Antigen uptake: Breaking convention

Yazmina Quintana-Perez1, Livia Lacerda Mariano1, Ana-Maria Lennon-Duménil1

  • 1Institut Curie, PSL University, INSERM U932, Immunity and Cancer, Paris, France.

Trends in Immunology
|July 15, 2026
PubMed

Insights

Macrophages can acquire antigens from living cells by sampling cytosol, expanding beyond the known pathway of phagocytosis of dying cells. This research reveals a novel mechanism for antigen uptake and processing.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • Antigen acquisition by macrophages is crucial for immune responses.
  • Historically, antigen uptake was understood primarily through phagocytosis of dying cells.
  • MHC restriction is a key concept in adaptive immunity.

Purpose of the Study:

  • To investigate novel mechanisms of antigen acquisition by macrophages.
  • To challenge the established paradigm of antigen uptake solely via phagocytosis.
  • To explore how macrophages interact with living cells for antigen sampling.

Main Methods:

  • Utilized advanced cellular imaging techniques.
  • Employed genetic manipulation of cells.
  • Performed biochemical assays to track antigen processing.

Main Results:

  • Demonstrated that macrophages can directly sample cytosol from living cells.
  • Showed this sampling bypasses conventional endolysosomal pathways.
  • Identified a new route for antigen presentation.

Conclusions:

  • Macrophage antigen acquisition is more diverse than previously thought.
  • Cytosolic sampling of living cells represents a significant new pathway.
  • This finding has implications for understanding immune surveillance and T cell activation.

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