CCR7 is mainly expressed in teleost gills, where it defines an IgD+IgM- B lymphocyte subset

• Published in: The Journal of immunology (1950) 2014-02, Vol.192 (3), p.1257-1266
• Main Authors: Castro, Rosario, Bromage, Erin, Abós, Beatriz, Pignatelli, Jaime, González Granja, Aitor, Luque, Alfonso, Tafalla, Carolina
• Format: Article
• Language: English
• Subjects: Animals; Antibody Specificity; B-Lymphocyte Subsets - metabolism; Female; Gene Expression Regulation, Developmental; Gills - cytology; Gills - growth & development; Gills - metabolism; Head Kidney - cytology; Head Kidney - growth & development; Head Kidney - metabolism; Hemorrhagic Septicemia, Viral - immunology; Immunoglobulin D - analysis; Immunoglobulin M - analysis; Lymphoid Tissue - cytology; Lymphoid Tissue - growth & development; Lymphoid Tissue - metabolism; Novirhabdovirus - physiology; Oncorhynchus mykiss - genetics; Oncorhynchus mykiss - growth & development; Oncorhynchus mykiss - immunology; Oncorhynchus mykiss - metabolism; Organ Specificity; Receptors, CCR7 - biosynthesis; Receptors, CCR7 - genetics; Receptors, CCR7 - immunology
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.1302471

Chemokine receptor CCR7, the receptor for both CCL19 and CCL21 chemokines, regulates the recruitment and clustering of circulating leukocytes to secondary lymphoid tissues, such as lymph nodes and Peyer's patches. Even though teleost fish do not have either of these secondary lymphoid structures, we have recently reported a homolog to CCR7 in rainbow trout (Oncorhynchus mykiss). In the present work, we have studied the distribution of leukocytes bearing extracellular CCR7 in naive adult tissues by flow cytometry, observing that among the different leukocyte populations, the highest numbers of cells with membrane (mem)CCR7 were recorded in the gill (7.5 ± 2% CCR7(+) cells). In comparison, head kidney, spleen, thymus, intestine, and peripheral blood possessed