Phagocytosis is the mechanism of capture and degradation of pathogens or debris that is performed by professional cells of the immune system. In certain circumstances, this process is impaired, which can lead to the development of opportunistic pathogens or chronic inflammation. We study the mechanims of capture and degradation of phagocytic cells, their impact on immune responses and their alterations by viral infections such as the Human Immunodeficiency Virus (HIV-1).
Professional phagocytes play a major role in innate and adaptive immune responses. Phagocytosis and degradation of invading microorganisms or debris is crucial for bacterial clearance and resolution of inflammation. Therefore, it is crucial to understand the mechanisms of phagocytosis, especially of cell debris or microorganisms.
Our first goal is to dissect the mechanisms used by phagocytes, in particular the coordinated activities of signaling pathways, membrane trafficking and cytoskeleton dynamics, and their effect on the outcome of immune responses. Second, we analyze how HIV infection or inflammatory conditions impair the phagocytic functions. Finally, we recently showed that part of the internalized material can be regurgitated without degradation and captured by B lymphocytes, a process that we aim to characterize further to better understand and manipulate the humoral immune response.
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Dumas A, Lê‑Bury G, Marie‑Anaïs F, Herit F, Mazzolini J, Guilbert T, Bourdoncle P., Russell DG, Benichou S, Zahraoui A, and Niedergang F. The HIV-1 protein Vpr impairs phagosome maturation by controlling microtubule-dependent trafficking.
J. Cell Biol. (2015) 211 : 359-372
MarionS, MazzoliniJ, HeritF, BourdoncleP,Kambou-PeneN, HailfingerS, SachseM, BenmerahA, EchardA, ThomeM and Niedergang F. The NF-κB signaling protein Bcl10 regulates actin dynamics by controlling AP1 and OCRL-bearing vesicles.
Le Roux D, Le Bon A, Dumas A, Taleb K, Sachse M, Sikora R, Julithe M, Benmerah A, Bismuth G and Niedergang F. Antigen stored in dendritic cells after macropinocytosis is released unprocessed from late endosomes to target B cells.
Mazzolini J, Herit F, Bouchet J, Benmerah A, Benichou S, Niedergang F. Inhibition of phagocytosis in HIV-1-infected macrophages relies on Nef-dependent alteration of focal delivery of recycling compartments.
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