Among differentially expressed genes, IL1B, IL17F, IL6R, CXCL2, CCL20 and
CCL25 were selected based on their immunological functions and CD8B and CD81 may contribute to variations of blood T lymphocyte subsets.
Though, it is still not fully clear why there is a tropism for the gastro-intestinal tract, advancements have been made in this area, identifying the chemokine receptor 9 (CCR9) as a predisposing factor, due to its motility enhancing effects of the cells, in conjunction with the presence of its ligand,
CCL25, expressed predominantly in the thymus and the epithelium of the small intestine [2].
Women had about 20% less
CCL25 and CCL26 than men, and 32% less CxCL1 (fracktalkine).
Based on the functional categorization of chemokines as described by Zlotnik and Yoshie [30], the elevated chemokines in TS-CONTROL compared to TS-COPD can be classified as follows: Inflammatory (CCL1, 7, and 15; CXCL2 and 9), homeostatic (CCL19,
CCL25), and dual function (CCL17).
[alpha]4[beta]7 and CCR9 can interact with mucosal vascular addressin cell adhesion molecule 1 (MAdCAM-1) and CC chemokine ligand 25 (
CCL25), respectively [41, 45].
(29) The [alpha]4[beta]7 specifically binds MAdCAM-1, and CCR9 is the receptor for the chemokine
CCL25 secreted by small intestinal venules.
Receptors and their ligands necessary for T-cell homing in the intestine include MAdCAM-1, integrin a4b7, lymphocyte function-associated antigen-1, intercellular adhesion molecule-1, very late antigen-4 (a4b1), vascular cell adhesion protein 1, CCR9,
CCL25, P-selectin glycoprotein ligand-1, and P-selectin [19].
Cutaneous melanoma has a distinct pattern of metastasis, preferentially targeting the submucosa of the small intestine probably via the CCR9 lymphocytes,
CCL25 thymus-expressed chemokine axis, and specific integrins [7].
More recently, they found that CXCL9, CXCL16, CCL20, and
CCL25 were specifically involved in MSC transendothelial migration across murine aortic endothelial cells (MAECs) [41].
The most differentially expressed genes were related to signal transduction, such as c-jug NF-[kappa] Bp65, neurotrophic factors (e.g., Mdk), chemokine and chemokine receptors (e.g., TECKI
CCL25), and interleukins such as IL-10 and IL-5, indicating a possible involvement of DU in cancer development, autoimmune diseases, and T helper 2 polarization ofT cells.