Persistent antigen presentation after acute vesicular stomatitis virus infection

Area of Science:

• Immunology
• Virology
• Cellular Biology

Background:

• Long-term antigen expression is crucial for modulating T-cell responses in chronic viral infections.
• Emerging evidence indicates immune responses can manifest late after seemingly acute viral infections.

Purpose of the Study:

• To investigate the CD8 T-cell response to vesicular stomatitis virus (VSV), an infection typically associated with rapid viral clearance.
• To determine the duration and location of antigen presentation following VSV infection.

Main Methods:

• Analysis of CD8 T-cell responses to intranasal VSV infection in mice.
• Detection of virus-encoded antigen in lymph nodes using adoptively transferred CD8 T cells.
• Comparison of antigen presentation duration between VSV and Listeria monocytogenes infections.
• Observation of T-cell clustering and dendritic cell interactions within lymph nodes.
• Phenotypic and functional characterization of late-emerging memory CD8 T cells.

Main Results:

• Virus-encoded antigen remained detectable for over 6 weeks post-infection in both draining and nondraining lymph nodes.
• Prolonged antigen presentation was specific to VSV infection, not observed with Listeria monocytogenes.
• Late after VSV infection, antigen-specific CD8 T cells formed clusters with dendritic cells in lymph nodes.
• Naïve CD8 T cells generated memory cells exhibiting characteristic phenotypes and functions.

Conclusions:

• Protracted antigen presentation occurs after apparently acute VSV infections.
• This sustained antigen presentation may contribute to ongoing antiviral immune responses.
• The findings challenge the notion of rapid clearance limiting T-cell engagement in acute viral infections.