INTRODUCTION Biological drugs are effective in patients with rheumatoid arthritis (RA), but increase severe infections. The CC chemokine receptor (CCR) 9 antagonist was effective for Crohn's disease without critical adverse effects including infections in clinical trials. The present study was carried out to explore the pathogenic roles of chemokine (C-C motif) ligand (CCL) 25 and its receptor,...

During embryonic development, T lymphoid precursor cells colonize the thymus. Chemoattraction by the fetal thymus is thought to mediate T precursor cell colonization. However, the molecules that attract T precursor cells to the thymus remain unclear. By devising time-lapse visualization in culture, the present results show that alymphoid fetal thymus lobes attract T precursor cells from fetal l...

PURPOSE Specific chemokines and their respective receptors have been implicated in distant tumor cell metastasis. Cutaneous melanoma has a distinct pattern of metastasis, preferentially targeting the submucosa of the small intestine. However, the underlying pathogenic mechanism remains unknown. Migration of CCR9(+) lymphocytes to the small intestine is known to occur in response to the chemoatt...

Rotaviruses (RV) are the most important cause of severe childhood diarrheal disease. In suckling mice, infection with RV results in an increase in total and virus-specific IgA(+) plasmablasts in the small intestinal lamina propria (LP) soon after infection, providing a unique opportunity to study the mechanism of IgA(+) cell recruitment into the small intestine. In this study, we show that the ...

Chemokines appear to have an important role in the seeding of lymphoid progenitors in the thymus, the regulation of the coordinated movements of the maturing T cells within this organ, and the egress of the resulting naive T cells to secondary lymphoid organs. CCR9, the specific receptor for the beta-chemokine TECK/CCL25, is selectively expressed in thymus, lymph node, and spleen. Using a speci...

BACKGROUND AIMS CCL25/CCR9 is a non-promiscuous chemokine/receptor pair and a key regulator of leukocyte migration to the small intestine. We investigated here whether CCL25/CCR9 interactions also play a role in the regulation of inflammatory responses in the large intestine. METHODS Acute inflammation and recovery in wild-type (WT) and CCR9(-/-) mice was studied in a model of dextran sulfate...

BACKGROUND CCL25/TECK and CCL28/MEC are CC chemokines primarily expressed in thymic dendritic cells and mucosal epithelial cells. Their receptors, CCR9 and CCR10, are mainly expressed on T and B lymphocytes. In human, mouse, pig and sheep CCL25 and CCL28 play an important role in the segregation and the compartmentalization of the mucosal immune system. As evidenced by early comparisons of germ...

Development of T cells in the thymus requires continuous importation of T-lineage progenitors from the bone marrow via the circulation. Following bone marrow transplant, recovery of a normal peripheral T-cell pool depends on production of naïve T cells in the thymus; however, delivery of progenitors to the thymus limits T-lineage reconstitution. Here, we examine homing of intravenously delivere...

CC chemokine receptor (CCR) 9, the receptor for the CC-chemokine CCL25/ thymus-expressed chemokine (TECK), is mainly expressed by thymocytes and by intraepithelial (IEL) and lamina propria lymphocytes of the small intestine. To study the biologic role of CCR9, a mouse strain was generated in which the CCR9 gene was deleted. In spite of the high level of CCR9 found in doubleand singlepositive th...