Related Experiment Video
Updated: Jun 25, 2026
Isolation of Lymphocytes from Mouse Genital Tract Mucosa
Published on: September 3, 2012
No significant CTL cross-priming by dendritic cell-derived exosomes during murine lymphocytic choriomeningitis virus
Ken Coppieters1, Ana María Barral, Amy Juedes
1Immune Regulation Laboratory DI-3, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
Insights
This study found that exosomes derived from dendritic cells (DCs) do not significantly contribute to CD8 T cell priming against lymphocytic choriomeningitis virus (LCMV). Exosomes from infected DCs failed to induce protective immunity in vivo, suggesting a limited role in antiviral CTL responses.
Area of Science:
- Immunology
- Virology
- Cell Biology
Background:
- Exosomes are vesicles involved in intercellular communication.
- Dendritic cells (DCs) can present antigens via exosomes, potentially influencing T cell responses.
- The role of DC-derived exosomes in antiviral immunity, particularly CD8 T cell priming, remains unclear.
Purpose of the Study:
- To investigate the contribution of DC-derived exosomes to CD8 T cell priming during lymphocytic choriomeningitis virus (LCMV) infection.
- To determine if exosomes from LCMV-infected DCs can activate antiviral CD8 T cell responses in vitro and in vivo.
Main Methods:
- Isolation and characterization of exosomes from cultured bone marrow-derived DCs (BMDCs) infected with LCMV or loaded with LCMV peptide.
- Flow cytometry analysis of exosome-bound beads.
- Incubation of exosome preparations with BMDCs to assess CD8 T cell activation.
- In vivo vaccination experiments to evaluate protective immunity.
Main Results:
- Exosomes derived from LCMV-infected or peptide-loaded BMDCs did not significantly enhance CD8 T cell cross-priming in vitro.
- Vaccination with exosomes from infected BMDCs did not confer protection against LCMV challenge in vivo.
- DC-derived exosomes showed limited capacity to prime LCMV gp33-specific naive and memory CD8 T cells.
Conclusions:
- DC-derived exosomes do not appear to play a significant role in initiating cytotoxic T lymphocyte (CTL) responses during acute LCMV infection.
- The findings suggest that exosomes may not be a major mechanism for antiviral CTL priming in this context.
Abstract:
Exosomes are small membrane vesicles of endocytic origin that are secreted by most cells in culture, but are also present in serum. They contain a wide array of protein ligands on their surface, which has led to the hypothesis that they might mediate intercellular communication. Indeed, data support that exosomes can transfer Ags to dendritic cells (DC), and, interestingly, that these DC can subsequently induce T cell priming or tolerance. We have investigated whether this concept can be expanded to antiviral immunity. We isolated exosomes from supernatant of cultured bone marrow-derived DC (BMDC) that were infected with lymphocytic choriomeningitis virus (LCMV) or loaded with an immunodominant LCMV peptide, and characterized them by flow cytometry upon binding to beads. We then incubated the exosome preparations with BMDC and looked at their potential to activate LCMV gp33-specific naive and memory CD8 T cells. We found that exosomes do not significantly contribute to CD8 T cell cross-priming in vitro. Additionally, exosomes derived from in vitro-infected BMDC did not exhibit significant in vivo priming activity, as evidenced by the lack of protection following exosome vaccination. Thus, DC-derived exosomes do not appear to contribute significantly to CTL priming during acute LCMV infection.
