Celiac.com 06/27/2017 - What can gene cells tell us about potential gut damage in people with celiac disease? Can they be harnessed to paint an accurate picture of what's going on in the gut?
A team of researchers recently set out to study autoimmunity and the transition in immune cells as dietary gluten induces small intestinal lesions. Specifically, they wanted to know if a B-cell gene signature correlates with the extent of gluten-induced gut damage in celiac disease.
They are variously affiliated with the Alvine Pharmaceuticals, Inc, San Carlos, California, the Department of Chemistry, Stanford, California, the Institute for Immunity, Transplantation and Infection, Stanford, California, the Division of Biomedical Informatics, Department of Medicine, Stanford, California, the Department of Chemical Engineering, Stanford, California, the Stanford ChEM-H, Stanford University, Stanford, California, the InterSystems Corporation, Cambridge, Massachusetts, the Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, the Department of Genetics, University of North Carolina, Chapel Hill, North Carolina, the EA Genomics, Division of Q2 Solutions, Morrisville, North Carolina, the Tampere Center for Child Health Research, Tampere, Finland, the University of Tampere Faculty of Medicine and Life Sciences, Tampere, Finland, the Department of Pediatrics, Tampere, Finland, the Department of Internal Medicine, Tampere, Finland, Tampere University Hospital, Tampere, Finland, and with the Division of Allergy/Immunology, Department of Medicine, University of California San Francisco, San Francisco, California.
The team looked at seventy-three celiac disease patients who followed a long-term, gluten-free diet. Those patients ingested a known amount of gluten daily for 6 weeks. Prior to the study, the team took a peripheral blood sample and intestinal biopsy specimens, then did the same after 6 weeks of gluten challenge.
To accurately quantify gluten-induced intestinal injury, they reported biopsy results on a continuous numeric scale that measured the villus-height–to–crypt-depth ratio.
As patient gut mucosa remained either relatively healthy or else deteriorated under the gluten challenge, the team isolated pooled B and T cells from whole blood, and used DNA microarray to analyze RNA for changes in peripheral B- and T-cell gene expression that correlated with changes in villus height to crypt depth.
As is often the case with celiac disease, intestinal damage from the gluten challenge varied considerably among the patients, ranging from no visible damage to extensive damage. Genes differentially expressed in B cells correlated strongly with the extent of gut damage. Increased B-cell gene expression correlated with a lack of sensitivity to gluten, whereas their decrease correlated with gluten-caused mucosal damage.
The the correlation with gut damage was tied to a core B-cell gene module, representing a subset of B-cell genes analyzed.
In patients with little to no intestinal damage, genes comprising the core B-cell module showed an overall increase in expression over the 6 week period.
This suggests that B-cell immune response in these patients may be a reaction to promote mucosal homeostasis and circumvent inflammation.
The idea that B-cell gene signature can reveal the extent of gut damage in celiac patients is intriguing. Clearly more research is needed to determine how this revelation might be harnessed to improve the evaluation and treatment of celiac disease.