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.

Expression of Membrane-Bound CC Chemokine Ligand 20 on Follicular T Helper Cells in T–B-Cell Conjugates

“…Instead, they rely on transcytosis of the ligands from the surrounding T cell zone, presenting them on their surface to attract CCR7 + T cells to secondary lymphoid organs ( 28 , 29 ). Therefore, it is possible that the source of CCL20 is the GC as both CCR6 and CCL20 are found in GC in lymphoid tissue ( 30 ) (Adrian Y. S. Lee and Heinrich Körner, unpublished data). To test whether CCL20 on Tfh int and Tfh cells is covalently expressed on the cell surface or bound via GAGs or others, we treated cells with an acid wash before staining.…”

Chemokine receptor CCR6 expression level and aggressiveness of prostate cancer

“…CCL20, which was originally identiWed in the liver, is the only chemokine known to interact with CCR6. CCL20 expression was demonstrated in several tissues, including normal prostatic tissue Power et al 1997) and lymph nodes (Rossi et al 1997;Hromas et al 1997;Baba et al 1997;Buri et al 2004). In hepatocellular-, pancreatic-and colorectal cancer (CRC), CCL20 stimulation in vitro led to enhanced proliferation and migration of CCR6 bearing cancer cells (Fujii et al 2004;KleeV et al 1999;Brand et al 2006;Uchida et al 2006).…”