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Updated: Aug 13, 2026

An Automated Culture System for Use in Preclinical Testing of Host-Directed Therapies for Tuberculosis
Published on: August 16, 2021
Apoptotic vesicles crossprime CD8 T cells and protect against tuberculosis
Florian Winau1, Stephan Weber, Subash Sad
1Department of Immunology, Max-Planck-Institute for Infection Biology, Schumannstrasse 21-22, 10117 Berlin, Germany. winau@mpiib-berlin.mpg.de
Abstract:
CD8 T lymphocytes are important effectors in protective immunity against Mycobacterium tuberculosis. We recently characterized the detour pathway of CD8 T cell activation in tuberculosis mediated by apoptotic vesicles from infected cells that transport mycobacterial antigens to dendritic cells (DCs). Here we demonstrate that apoptotic vesicles from mycobacteria-infected macrophages stimulate CD8 T cells in vivo. Homing of DCs to draining lymph nodes was critically required for effective crosspriming. Subsequent fate of vesicle-associated antigens in recipient DCs was characterized by endosomal mechanisms predominating over proteasomal processing. In addition, vesicle processing depended on the presence of saposins to disintegrate apoptotic membranes. Apoptotic vesicles displayed potent adjuvant activity by stimulating through Toll-like receptors (TLR). Ultimately, vaccination with vesicles from infected cells induced protection against M. tuberculosis infection. Taken together, we propose the detour pathway to represent a genuine immunological mechanism mediating crosspriming of CD8 T cells in vivo and protection against tuberculosis.
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