Goettel, J. | Search bioRxiv

bioRxiv2023

Eosinophils exert direct and indirect anti-tumorigenic effects in the development of esophageal squamous cell carcinoma

Background/AimsEosinophils are present in several solid tumors and have context-dependent function. Our aim is to define the contribution of eosinophils in esophageal squamous cell carcinoma (ESCC), since their role in ESCC is unknown. MethodsEosinophils were enumerated in tissues from two ESCC cohorts. Mice were treated with 4-nitroquinolone-1-oxide (4-NQO) for 8 weeks to induce pre-cancer or 16 weeks to induce carcinoma. Eosinophil number was modified by monoclonal antibody to IL-5 (IL5mAb), recombinant IL-5 (rIL-5), or genetically with eosinophil-deficient ({Delta}dblGATA) mice or mice deficient in eosinophil chemoattractant eotaxin-1 (Ccl11-/-). Esophageal tissue and eosinophil specific RNA-sequencing was performed to understand eosinophil function. 3-D co-culturing of eosinophils with pre-cancer or cancer cells was done to ascertain direct effects of eosinophils. ResultsActivated eosinophils are present in higher numbers in early stage versus late stage ESCC. Mice treated with 4-NQO exhibit more esophageal eosinophils in pre-cancer versus cancer. Correspondingly, epithelial cell Ccl11 expression is higher in mice with pre-cancer. Eosinophil depletion using three mouse models (Ccl11-/- mice, {Delta}dblGATA mice, IL5mAb treatment) all display exacerbated 4-NQO tumorigenesis. Conversely, treatment with rIL-5 increases esophageal eosinophilia and protects against pre-cancer and carcinoma. Tissue and eosinophil RNA-sequencing revealed eosinophils drive oxidative stress in pre-cancer. In vitro co-culturing of eosinophils with pre-cancer or cancer cells resulted in increased apoptosis in the presence of a degranulating agent, which is reversed with N-acetylcysteine, a reactive oxygen species (ROS) scavenger. {Delta}dblGATA mice exhibited increased CD4 T cell infiltration, IL-17, and enrichment of IL-17 pro-tumorigenic pathways. ConclusionEosinophils likely protect against ESCC through ROS release during degranulation and suppression of IL-17.

cancer biology↗

bioRxiv2022

Group 3 Innate Lymphoid Cells are regulated by WASP in a microbiota-dependent manner

Wiskott-Aldrich syndrome protein (WASP) is a cytoskeletal regulator that is largely restricted to hematopoietic cells. While WASP expression in both lymphocytes and macrophages play a critical role in maintaining intestinal homeostasis, the function of WASP in innate lymphoid cells is unknown. Here we analyzed the role of WASP in the differentiation and function of group 3 innate lymphoid cells (ILC3s). WASP-deficient mice (Was-/-) have a marked reduction in ILC3s. Moreover, antimicrobial peptide expression in response to ILC3-derived IL-22 was also reduced in the absence of WASP. In Was-/- mice, we observed a reduction in CCR6+ ILC3s, cells known to restrict immune responses to commensal bacteria. WASP-deficient mice were more susceptible to Citrobacter rodentium, an enteric infection controlled by ILC3s. Interestingly, there was no reduction in ILC3s in Was-/- germ-free mice when compared to WT germ-free mice. ILC3s lacking WASP expression also demonstrated microbially-dependent alterations in gene expression associated with cell migration. Finally, ILC3-like (Rorgt+CD3-) cells were reduced in the GI tract of WASP-deficient patients. In conclusion, ILC3-specific expression of WASP is critical for the generation and function of ILC3s in the presence of commensal microflora. Aberrant ILC3 function in the setting of WASP-deficiency may contribute to underlying disease pathogenesis.

immunology↗