IMMUNOLOGY2026™ Conference Recordings For Attendees-CD4 T cell memory in acute and chronic viral infection

Video Transcription

Video Summary

The speaker discusses research on CD4 T cells during acute and chronic viral infections, using LCMV mouse models to compare immune responses. In chronic infection, type 1 helper (Th1) CD4 T cells are progressively lost or converted into T follicular helper (TFH) cells, largely driven by ongoing type I interferon signaling. This loss weakens antiviral immunity. Restoring Th1 cells, or blocking PD-L1, specifically boosts Th1 responses, improves CD8 T-cell function, enhances virus control, and even induces cytotoxic CD4 T cells (CD4 CTLs).  <br /><br />In acute infection, the speaker shows that CD4 CTLs arise early from Th1 cells, are dependent on perforin, and persist as memory cells. These cells are not just effectors but regulators: they limit the magnitude and shape of the immune response by selectively interacting with germinal center B cells and inducing their apoptosis. This pruning appears to influence antibody responses and overall immune balance, helping protect against excessive immunity and pathology.  <br /><br />The talk concludes that CD4 T-cell subsets are highly plastic and functionally important in both chronic and acute infection, with therapeutic implications for checkpoint blockade, antiviral immunity, and possibly vaccination.

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Date April 19, 2026 8:00 AM - 9:30 AM

Room 153C

Session Remember Me! - Exploration of the full spectrum of immune memory, Sponsored by the Canadian Society of Immunology (CSI)

Speaker David Brooks

Track Lymphocyte Differentiation and Peripheral Maintenance (LYM)

Year 2026

Keywords

David Brooks

CD4 T cells

acute viral infection

chronic viral infection

Th1 cells

TFH cells

PD-L1 blockade

CD4 cytotoxic T cells

April 19, 2026 8:00 AM - 9:30 AM

153C

Remember Me! - Exploration of the full spectrum of immune memory, Sponsored by the Canadian Society of Immunology (CSI)

2026

Lymphocyte Differentiation and Peripheral Maintenance (LYM)