IMMUNOLOGY2026™ Conference Recordings For Attendees-Counting to 9: the amazing adventures of the 9th interleukin

Video Transcription

Video Summary

Mark Kaplan’s lecture focused on IL-9, a cytokine with complex, context-dependent roles in immunity. He described how his lab helped define IL-9-producing T cells, including classical Th9 cells and more polyfunctional tissue-resident memory T cells that co-produce IL-9 with other Th2 cytokines. The talk highlighted transcriptional control of these cells, especially the role of PU.1 in regulating cytokine heterogeneity and IL-9 production.<br /><br />Kaplan also reviewed work showing that IL-9 acts on multiple target cells in different tissues. In allergic lung inflammation, IL-9 signaling affects mast cells and macrophages, influencing airway hyperreactivity, inflammation, and tumor growth in the lung. In the bladder, IL-9 receptor is highly expressed on urothelial cells and macrophages, and IL-9 is important for controlling uropathogenic E. coli infection and promoting bacterial clearance.<br /><br />Overall, the lecture argued that IL-9 is neither simply pro-inflammatory nor dispensable; instead, its function depends on the tissue, responding cell types, and disease context. Kaplan concluded by emphasizing the therapeutic potential of targeting or enhancing IL-9 in selected settings and underscored the importance of public funding for scientific research.

Meta Tag

Date April 18, 2026 6:00 PM - 6:45 PM

Room Ballroom

Session Distinguished Lecture - Mark H. Kaplan

Speaker Mark Kaplan

Track Immune Response Regulation: Molecular Mechanisms (IRM)

Year 2026

Keywords

IL-9

cytokine

Th9 cells

tissue-resident memory T cells

PU.1

allergic lung inflammation

bladder immunity

uropathogenic E. coli

April 18, 2026 6:00 PM - 6:45 PM

Ballroom

Distinguished Lecture - Mark H. Kaplan

Mark Kaplan

Immune Response Regulation: Molecular Mechanisms (IRM)

2026