title: The chemokines CCL11, CCL20, CCL21, and CCL24 are preferentially expressed in polarized human secondary lymphoid follicles.
abstract: Chemokines regulate cellular trafficking to and from lymphoid follicles. Here, the distribution pattern of four CCL chemokines is defined by in situ hybridization in human lymphoid follicles from tonsils and lymph nodes (LNs) of newborns and adults. Cells expressing CCL11 (eotaxin) and CCL20 (Exodus) were preferentially located within follicles, while cells expressing CCL21 (secondary lymphoid-tissue chemokine) and CCL24 (eotaxin-2) mRNA were almost exclusively found in the perifollicular areas. Hence, the two CCR3-binding chemokines, CCL11 and CCL24, showed a mutually exclusive expression pattern in the intra- and extra-follicular areas, respectively. Chemokine gene expression paralleled follicular maturation: in tonsils, where approximately 80% of follicles are polarized, CCL11 and CCL20 mRNA-positive cells were detected more frequently than in lymph nodes from adults, where about half of follicles are non-polarized. No intrafollicular chemokine expression was detectable in the primary follicles from newborns. Extrafollicular cells expressing CCL21 and CCL24 were again more frequent in tonsils than in LNs from adults. The observed preferential presence of cells expressing CC chemokines in polarized human lymphoid follicles indicates that chemokines are not only instrumental in the induction of follicle formation, but may also be involved in their further differentiation.
authors.affiliation: Institute of Pathology, University of Bern, CH-3010 Bern, Switzerland.
authors.forename: Caroline
authors.initials: C
authors.lastname: Buri
authors.forename: Andreas
authors.initials: A
authors.lastname: Gutersohn
authors.forename: Chantal
authors.initials: C
authors.lastname: Hauser
authors.forename: Andreas
authors.initials: A
authors.lastname: Kappeler
authors.forename: Christoph
authors.initials: C
authors.lastname: Mueller
mesh_terms: D000328:Adult; D020533:Angiogenesis Inhibitors / Q000032:analysis / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002465:Cell Movement / Q000235:genetics / Q000502:physiology; D054413:Chemokine CCL11; D054418:Chemokine CCL20; D054421:Chemokine CCL21; D054423:Chemokine CCL24; D019742:Chemokines, CC / Q000032:analysis* / Q000235:genetics; D015870:Gene Expression / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D007231:Infant, Newborn; D008198:Lymph Nodes / Q000737:chemistry; D008221:Lymphoid Tissue / Q000737:chemistry*; D019402:Macrophage Inflammatory Proteins / Q000032:analysis / Q000235:genetics; D014066:Palatine Tonsil / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D020533:Angiogenesis Inhibitors; C515456:CCL11 protein, human; C108355:CCL20 protein, human; C515478:CCL21 protein, human; C515484:CCL24 protein, human; D054413:Chemokine CCL11; D054418:Chemokine CCL20; D054421:Chemokine CCL21; D054423:Chemokine CCL24; D019742:Chemokines, CC; D019402:Macrophage Inflammatory Proteins; D012333:RNA, Messenger