West Nile virus triggers intestinal dysmotility via T cell–mediated enteric nervous system injury
Hana Janova, … , Thaddeus S. Stappenbeck, Michael S. Diamond
Hana Janova, … , Thaddeus S. Stappenbeck, Michael S. Diamond
Published August 29, 2024
Citation Information: J Clin Invest. 2024;134(21):e181421. https://doi.org/10.1172/JCI181421.
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Research Article Gastroenterology Infectious disease

West Nile virus triggers intestinal dysmotility via T cell–mediated enteric nervous system injury

Abstract

Intestinal dysmotility syndromes have been epidemiologically associated with several antecedent bacterial and viral infections. To model this phenotype, we previously infected mice with the neurotropic flavivirus West Nile virus (WNV) and demonstrated intestinal transit defects. Here, we found that within 1 week of WNV infection, enteric neurons and glia became damaged, resulting in sustained reductions of neuronal cells and their networks of connecting fibers. Using cell-depleting antibodies, adoptive transfer experiments, and mice lacking specific immune cells or immune functions, we show that infiltrating WNV-specific CD4+ and CD8+ T cells damaged the enteric nervous system (ENS) and glia, which led to intestinal dysmotility; these T cells used multiple and redundant effector molecules including perforin and Fas ligand. In comparison, WNV-triggered ENS injury and intestinal dysmotility appeared to not require infiltrating monocytes, and damage may have been limited by resident muscularis macrophages. Overall, our experiments support a model in which antigen-specific T cell subsets and their effector molecules responding to WNV infection direct immune pathology against enteric neurons and supporting glia that results in intestinal dysmotility.

Authors

Hana Janova, Fang R. Zhao, Pritesh Desai, Matthias Mack, Larissa B. Thackray, Thaddeus S. Stappenbeck, Michael S. Diamond

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Figure 7

Mice lacking perforin and Fas/FasL signaling do not develop WNV-triggered GI dysmotility or neuronal and glial network injury.

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Mice lacking perforin and Fas/FasL signaling do not develop WNV-triggere...
(A) Scheme for the generation of Prf1–/– Faslgld/gld (DKO) mice. The figure in A was created using BioRender software. (B) GI transit time in WNV-infected WT or DKO mice at 7 dpi. (C) Proportions of WNV-infected WT and DKO mice showing abnormal bowel dilation in the small intestine at 7 dpi. (D–G) The muscularis externa was isolated from the middle regions of small intestines from sham- (D and E) or WNV-infected WT or DKO (F and G) mice at 7 dpi and stained. (D–F) The fraction of the area that stained positive for calretinin, nNOS, S100β, and WNV antigen was determined, and values were normalized to those for (D and E) sham-infected WT mice or (F) WNV-infected WT mice. (G) The numbers of CD3+ cells in the myenteric plexus were calculated by dividing the area positive for CD3 staining with the average size of CD3+ cells. Cell counts are expressed as the number of CD3+ cells per mm2. (D and G) Representative images of the myenteric plexus of the middle region of the small intestine. Scale bars: 100 μm. Original magnification, ×2.5 (enlarged insets). Data were pooled from (B, C, and F) 5 and (D, E, and G) 4 experiments. The numbers of mice per group were as follows: (B and C) n = 13–16; (D and E) n = 8–10; (F) n = 10–15; (G) n = 10. Lines in B and column heights in D–G indicate mean values. *P < 0.05, **P < 0.01, and ***P < 0.001, by (B, F, and G) 2-tailed Mann-Whitney U test and (D and E) Kruskal-Wallis ANOVA with Dunn’s post test.