title: Induction of RET dependent and independent pro-inflammatory programs in human peripheral blood mononuclear cells from Hirschsprung patients.
abstract: Hirschsprung disease (HSCR) is a rare congenital anomaly characterized by the absence of enteric ganglia in the distal intestinal tract. While classified as a multigenic disorder, the altered function of the RET tyrosine kinase receptor is responsible for the majority of the pathogenesis of HSCR. Recent evidence demonstrate a strong association between RET and the homeostasis of immune system. Here, we utilize a unique cohort of fifty HSCR patients to fully characterize the expression of RET receptor on both innate (monocytes and Natural Killer lymphocytes) and adaptive (B and T lymphocytes) human peripheral blood mononuclear cells (PBMCs) and to explore the role of RET signaling in the immune system. We show that the increased expression of RET receptor on immune cell subsets from HSCR individuals correlates with the presence of loss-of-function RET mutations. Moreover, we demonstrate that the engagement of RET on PBMCs induces the modulation of several inflammatory genes. In particular, RET stimulation with glial-cell line derived neurotrophic factor family (GDNF) and glycosyl-phosphatidylinositol membrane anchored co-receptor α1 (GFRα1) trigger the up-modulation of genes encoding either for chemokines (CCL20, CCL2, CCL3, CCL4, CCL7, CXCL1) and cytokines (IL-1β, IL-6 and IL-8) and the down-regulation of chemokine/cytokine receptors (CCR2 and IL8-Rα). Although at different levels, the modulation of these "RET-dependent genes" occurs in both healthy donors and HSCR patients. We also describe another set of genes that, independently from RET stimulation, are differently regulated in healthy donors versus HSCR patients. Among these "RET-independent genes", there are CSF-1R, IL1-R1, IL1-R2 and TGFβ-1, whose levels of transcripts were lower in HSCR patients compared to healthy donors, thus suggesting aberrancies of inflammatory responses at mucosal level. Overall our results demonstrate that immune system actively participates in the physiopathology of HSCR disease by modulating inflammatory programs that are either dependent or independent from RET signaling.
authors.affiliation: Laboratory of Molecular Genetics, IRCCS, Giannina Gaslini Istitute, Genoa, Italy.
authors.forename: Marta
authors.initials: M
authors.lastname: Rusmini
authors.forename: Paola
authors.initials: P
authors.lastname: Griseri
authors.forename: Francesca
authors.initials: F
authors.lastname: Lantieri
authors.forename: Ivana
authors.initials: I
authors.lastname: Matera
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Hudspeth
authors.forename: Alessandra
authors.initials: A
authors.lastname: Roberto
authors.forename: Joanna
authors.initials: J
authors.lastname: Mikulak
authors.forename: Stefano
authors.initials: S
authors.lastname: Avanzini
authors.forename: Valentina
authors.initials: V
authors.lastname: Rossi
authors.forename: Girolamo
authors.initials: G
authors.lastname: Mattioli
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Jasonni
authors.forename: Roberto
authors.initials: R
authors.lastname: Ravazzolo
authors.forename: William J
authors.initials: WJ
authors.lastname: Pavan
authors.forename: Alessio
authors.initials: A
authors.lastname: Pini-Prato
authors.forename: Isabella
authors.initials: I
authors.lastname: Ceccherini
authors.forename: Domenico
authors.initials: D
authors.lastname: Mavilio
mesh_terms: D002478:Cells, Cultured; D016000:Cluster Analysis; D016207:Cytokines / Q000378:metabolism; D005091:Exons; D015870:Gene Expression; D020869:Gene Expression Profiling; D005838:Genotype; D006627:Hirschsprung Disease / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology / Q000378:metabolism; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism; D009000:Monocytes / Q000276:immunology / Q000378:metabolism; D009154:Mutation; D020641:Polymorphism, Single Nucleotide; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics / Q000378:metabolism*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D051096:Proto-Oncogene Proteins c-ret