Immune System and Related Disorders

ASPIRE is a nutrition study focusing on the effect of arginine supplementation on immune function in postoperative infants. The investigators will explore the effect of current intravenous feeding (parenteral nutrition (PN)) formulations and oral arginine supplementation on blood arginine levels and the genes that are involved in body nutrition and fighting infection in babies who have had major bowel surgery or been diagnosed with necrotising enterocolitis. The investigators will undertake an exploratory physiological study across two sites under which are part of a single neonatal partnership. 48 infants will be recruited; 24 preterm infants and 24 term/near term infants. 16 of these infants (8 preterm and 8 term/near term) will be supplemented with arginine in both oral and parenteral form, 16 infants will receive arginine supplementation in oral form alone and 16 infants will receive standard nutrition with no arginine supplement. The investigators will record nutritional intake and routine biochemical testing data (which includes amino acid levels) collected over the first 30 days post surgery or post NEC diagnosis. The investigators will take blood for analysis at prespecified intervals for RNA sequencing, ammonia and metabolomics. RNA sequencing findings will allow the investigators to describe the effect of arginine on gene activity in postoperative infants The investigators hypothesise that arginine supplementation will result in changes in gene expression that are consistent with changes in T-cell function and associated inflammatory pathways.

The purpose of this study is to understand how cells of the immune system use the common sugar glucose to fuel energy production and as a building block within the cell. Investigators will intravenously infuse a non-radioactive glucose tracer into participants over a few hours and collect immune cells from the blood to track uptake and usage of this glucose within these immune cells.

The prevalence of atopic dermatitis has increased along with urbanization and biodiversity loss. According to biodiversity hypothesis, the main reason is urban lifestyle and reduced contact to microbial diversity. Previous studies indicate association between atopic dermatitis and exposure to natural microbes in childhood. Sand Play - the Effect of Biodiversity Exposure on Atopic Dermatitis will investigate whether the exposure to microbial diversity in sandbox reduces the symptoms of atopic dermatitis, alters commensal microbiota and modifies immune regulation in children.

In recent years, single-cell high-throughput sequencing technology has developed rapidly and is widely used in research related to the immune system, breaking traditional cognition and gaining a new understanding of immune cell classification. In particular, the emerging single cell RNA sequencing (scRNA-seq) provides new ideas for the study of cell heterogeneity in multicellular organisms. Analyzing the changes in the expression profile of the cell transcriptome at the single-cell level can clearly show the changes in the trajectory of individual cells, reveal new cell types, and discover the potential functions of immune cells. Therefore, this study intends to recruit healthy adults and use multi-omics techniques such as single-cell sequencing to systematically classify the peripheral blood mononuclear cells of healthy adults to provide a basis for further disease-related research.

Colorectal and pancreatobiliary cancers are the most common digestive cancers. Their incidence has particularly increased over the last few decades, leading to suspicion that environmental factors are involved. In addition, strategies for the therapeutic management of these cancers are evolving in the context of the development of immunotherapies. Tumor microenvironment is a potential source of new diagnostic, prognostic and predictive markers and new therapeutic targets. The links between tumor microenvironment and modulation of the immune system in colorectal and pancreatobiliary cancers are poorly understood. Molecular classifications have been proposed for these cancers, but their link with immunity and response to treatment remains to be explored. Objective : explore links between molecular subtypes, tumor microenvironment, host (immune system, pre-metastatic niche, intestinal microbiota, metabolism), and survival (prognostic value), response (predictive value) and tolerance (toxicities) to treatments in digestive cancers, in particular colorectal and pancreatobiliary cancers. Method: Retrospective and prospective monocentric cohort study