Lung IL-33 is involved in pathogen defense, barrier homeostasis, and development of allergic responses. We previously identified a 5 kb noncoding region within a GWAS-defined segment that regulates expression of human IL33 (hIL33) but is absent in the murine locus. To understand how this region affects IL-33 expression in vivo, we engineered 2 BAC-transgenic strains in which 166 kb of the human genome upstream of the hIL33 locus, along with a fluorescent reporter, was inserted into the murine genome, both with and without the 5 kb region. Comparison to a murine Il33 (mIl33) reporter strain revealed species-specific tropism; hIL33 reporter was mostly expressed in the endothelium, while mIl33 reporter was expressed in type 2 alveolar epithelium. hIL33 reporter expression in tracheal basal epithelium, submucosal glands, and lung microvasculature required the 5 kb region. Surprisingly, allergen and exogenous IL-33 downregulated hIL33 reporter in lung endothelium only when the 5 kb region was present. Similar IL-33–dependent downregulation of IL33 transcripts was observed in human endothelial cell lines, validating that our hIL33 reporter strain recapitulated human endothelial biology. Together, these data reveal the importance of the asthma-associated human 5 kb region in regulating human IL33 expression in a cell type– and context-dependent manner.
Maile K. Hollinger, Chanie L. Howard, Donna C. Decker, Kelly M. Blaine, Ivy Aneas, Emily M. Grayson, Tania E. Velez, Fernando A. Oliveira, Riley T. Hannan, Daniel F. Camacho, Philip A. Verhoef, Cara L. Hrusch, Rebecca S. Griffes, Jeffrey M. Sturek, Marcelo A. Nobrega, Nathan Schoettler, Anne I. Sperling
Usage data is cumulative from May 2026 through May 2026.
| Usage | JCI | PMC |
|---|---|---|
| Text version | 129 | 0 |
| 23 | 0 | |
| Figure | 48 | 0 |
| Table | 16 | 0 |
| Supplemental data | 20 | 0 |
| Citation downloads | 12 | 0 |
| Totals | 248 | 0 |
| Total Views | 248 | |
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.