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Updated: May 28, 2026

Assessing the Innate Sensing of HIV-1 Infected CD4+ T Cells by Plasmacytoid Dendritic Cells Using an Ex vivo Co-culture System.
Published on: September 1, 2015
A platelet-mediated system for shuttling blood-borne bacteria to CD8α+ dendritic cells depends on glycoprotein GPIb
Admar Verschoor1, Michael Neuenhahn, Alexander A Navarini
1Institute for Medical Microbiology, Immunology and Hygiene, and Focus Group, Clinical Cell Processing and Purification, Technische Universität München, Munich, Germany. admar.verschoor@mikrobio.med.tum.de
Abstract:
The acquisition of pathogen-derived antigen by dendritic cells (DCs) is a key event in the generation of cytotoxic CD8(+) T cell responses. In mice, the intracellular bacterium Listeria monocytogenes is directed from the blood to splenic CD8α(+) DCs. We report that L. monocytogenes rapidly associated with platelets in the bloodstream in a manner dependent on GPIb and complement C3. Platelet association targeted a small but immunologically important portion of L. monocytogenes to splenic CD8α(+) DCs, diverting bacteria from swift clearance by other, less immunogenic phagocytes. Thus, an effective balance is established between maintaining sterility of the circulation and induction of antibacterial immunity by DCs. Other gram-positive bacteria also were rapidly tagged by platelets, revealing a broadly active shuttling mechanism for systemic bacteria.
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