Bronchiolitis obliterans syndrome (BOS) is a progressive, fatal obstructive lung disease that occurs following lung transplant, where it is termed chronic lung allograft dysfunction BOS (CLAD-BOS), or as the primary manifestation of pulmonary chronic graft versus host disease (cGVHD-BOS) following allogeneic hematopoietic stem cell transplant. Disease pathogenesis is poorly understood; however, chronic alloreactivity is common to both conditions, suggesting a shared pathophysiology. We performed single-cell RNA-Seq (scRNA-Seq) on explanted human lungs from 4 patients with CLAD-BOS, 3 patients with cGVHD-BOS, and 3 deceased controls to identify cell types, genes, and pathways enriched in BOS to better understand disease mechanisms. In both forms of BOS, we found an expanded population of CD8+ tissue resident memory T cells (TRM), which was distinct to BOS compared with other chronic lung diseases. In addition, BOS samples expressed genes and pathways associated with macrophage chemotaxis and proliferation, including in nonimmune cell populations. We also identified dysfunctional stromal cells in BOS, characterized by pro- and antifibrotic gene programs. These data suggest substantial cellular and molecular overlap between CLAD- and cGVHD-BOS and, therefore, common pathways for possible therapeutic intervention.
Patrick W. Mellors, Ana N. Lange, Bruno Casino Remondo, Maksim Shestov, Joseph D. Planer, Andrew R. Peterson, Yun Ying, Su Zhou, Jason D. Christie, Joshua M. Diamond, Edward Cantu, Maria C. Basil, Saar Gill
Usage data is cumulative from April 2025 through December 2025.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 2,435 | 362 |
| 580 | 93 | |
| Figure | 446 | 0 |
| Supplemental data | 316 | 29 |
| Citation downloads | 123 | 0 |
| Totals | 3,900 | 484 |
| Total Views | 4,384 | |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.