Retinoic Acid Signaling Modulates Recipient Gut Barrier Integrity and Microbiota After Allogeneic Hematopoietic Stem Cell Transplantation in Mice

• Published in: Frontiers in immunology Vol. 12; p. 749002
• Main Authors: Pan, Pan, Atkinson, Samantha N, Taylor, Brian, Zhu, Haojie, Zhou, Dian, Flejsierowicz, Philip, Wang, Li-Shu, Morse, Matthew, Liu, Chen, Gunsolus, Ian L, Chen, Xiao
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 25.10.2021
• Subjects: Animals; Caco-2 Cells; Feces - microbiology; Gastrointestinal Microbiome - drug effects; Gastrointestinal Microbiome - genetics; Graft vs Host Disease; graft-versus-host disease; gut microbiota; Hematopoietic Stem Cell Transplantation; Humans; Immunology; intestinal barrier; Intestinal Mucosa - drug effects; Intestinal Mucosa - metabolism; Lung - drug effects; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Permeability - drug effects; retinoic acid; RNA, Ribosomal, 16S; Signal Transduction - drug effects; Transplantation, Homologous; vitamin A; Vitamin A - pharmacology; Vitamins - pharmacology; retinoic acid; vitamin A; intestinal barrier; graft-versus-host disease; gut microbiota
• DOI: 10.3389/fimmu.2021.749002
• ISSN: 1664-3224

Graft-versus-host disease (GVHD) remains a major complication after allogeneic hematopoietic stem cell transplantation (HSCT). An impaired intestinal epithelial barrier is an important component of GVHD pathogenesis. However, contributing host factors that modulate mucosal barrier integrity during GVHD are poorly defined. We hypothesized that vitamin A and retinoic acid (RA) exert positive impacts on maintaining intestinal barrier function after HSCT, thus preventing or dampening GVHD severity. Unexpectedly, we found that exogenous RA increased intestinal permeability of recipient mice after allogeneic HSCT. Serum bacterial endotoxin levels were significantly higher in GVHD mice fed a vitamin A-high (VAH) diet compared to those fed a vitamin A-normal (VAN) diet, indicating a more compromised intestinal barrier function. Furthermore, VAH mice showed more severe lung GVHD with increased donor T cell infiltration in this tissue and died significantly faster than VAN recipients. 16S rRNA sequencing of fecal samples revealed significant differences in the diversity and composition of gut microbiota between VAN and VAH transplant recipients. Collectively, we show that retinoic acid signaling may negatively impact intestinal barrier function during GVHD. Mild vitamin A supplementation is associated with increased lung GVHD and more profound gut dysbiosis. Micronutrients such as vitamin A could modulate complications of allogeneic HSCT, which may be mediated by shaping gut microbiota.