Abnormalities in CD57+ cytotoxic T cells and Vδ1+ γδT cells in subclinical celiac disease in childhood are affected by cytomegalovirus. The Generation R Study

Viruses and celiac disease: what do we know ?

The aim of this review is to provide a comprehensive overview about the link between viruses and celiac disease. A systematic search on PubMed, Embase, and Scopus was conducted on March 07, 2023. The reviewers independently selected the articles and chose which articles to include. The review is a textual systemic review, and all relevant articles were included based on title and abstract. If there was a disagreement between the reviewers, they came to a consensus during deliberation sessions. A total of 178 articles were selected for the review and read in full; only part of them was retained. We found studies between celiac disease and 12 different viruses. Some of the studies were done only on small groups. Most studies were on pediatric population. Evidence for an association was found with several viruses (trigger or protective). It seems that only a part of the viruses could induce the disease. Several points are important to keep in mind: firstly, simple mimicry or that the virus induces a high level of TGA is not sufficient to promote the disease. Secondly, inflammatory background is necessary to induce CD with virus. Thirdly, IFN type 1 seems to have an important role. Some of the viruses are potential or known triggers like enteroviruses, rotaviruses, reoviruses, and influenza. Further studies are needed to better understand the role of viruses in celiac disease to better treat and prevent the disease.

Characterization of the γδ T-cell compartment during infancy reveals clear differences between the early neonatal period and 2 years of age

γδ T cells are unconventional T cells that function on the border of innate and adaptive immunity. They are suggested to play important roles in neonatal and infant immunity, although their phenotype and function are not fully characterized in early childhood. We aimed to investigate γδ T cells in relation to age, prematurity and cytomegalovirus (CMV) infection. Therefore, we used flow cytometry to characterize the γδ T-cell compartment in cord blood and peripheral blood cells from 14-day-, 2-year- and 5-year-old children, as well as in peripheral blood samples collected at several time points during the first months of life from extremely premature neonates. γδ T cells were phenotypically similar at 2 and 5 years of age, whereas cord blood was divergent and showed close proximity to γδ T cells from 14-day-old neonates. Interestingly, 2-year-old children and adults showed comparable Vδ2+ γδ T-cell functionality toward both microbial and polyclonal stimulations. Importantly, extreme preterm birth compromised the frequencies of Vδ1+ cells and affected the functionality of Vδ2+ γδ T cells shortly after birth. In addition, CMV infection was associated with terminal differentiation of the Vδ1+ compartment at 2 years of age. Our results show an adult-like functionality of the γδ T-cell compartment already at 2 years of age. In addition, we demonstrate an altered γδ T-cell phenotype early after birth in extremely premature neonates, something which could possible contribute to the enhanced risk for infections in this vulnerable group of children.