IMMUNOLOGY2026™ Conference Recordings For Attendees-Decoding Immune Responses in Heart Transplantation: Lessons for Xenografts and Clinical Translation

Decoding Immune Responses in Heart Transplantation: Lessons for Xenografts and Clinical Translation

Video Transcription

Video Summary

The speaker discussed why cardiac xenotransplants still fail even when hyperacute rejection is prevented. Using single-nucleus RNA sequencing and histopathology from two human heart xenograft recipients with different injury patterns—one with mainly intrinsic/viral injury and minimal immune infiltration, the other with strong immune-mediated rejection—they found a shared central mechanism: endothelial dysfunction. Despite different triggers, both grafts showed nearly identical endothelial activation, angiopoietin-2 dominance, capillary loss, microvascular collapse, and fibrosis. Activated endothelium also appeared to recruit and amplify immune cells through chemokine, adhesion, and antigen-presentation pathways. In patient two, this was associated with organized myeloid and cytotoxic lymphoid expansion. The study proposes that endothelial activation is not just a marker of injury but a driver that shapes downstream fibrosis and cardiomyocyte dysfunction. The main implication is that therapies targeting endothelial reactivity may improve xenotransplant survival.

Meta Tag

Date April 17, 2026 8:00 AM - 9:30 AM

Room 151

Session The Immunology of Xenotransplantation: From Bench Discovery to Clinical Translation, Sponsored by the Amer. Soc. of Transplantation (AST)

Speaker Valeria Mas

Track Transplantation Immunology (TRAN)

Year 2026

Keywords

cardiac xenotransplant

endothelial dysfunction

single-nucleus RNA sequencing

immune-mediated rejection

angiopoietin-2

April 17, 2026 8:00 AM - 9:30 AM

151

The Immunology of Xenotransplantation: From Bench Discovery to Clinical Translation, Sponsored by the Amer. Soc. of Transplantation (AST)

Valeria Mas

Transplantation Immunology (TRAN)

2026