title: MCP-1/CCR2 interactions direct migration of peripheral B and T lymphocytes to the thymus during acute infectious/inflammatory processes.
abstract: Mature lymphocyte immigration into the thymus has been documented in mouse, rat, and pig models, and highly increases when cells acquire an activated phenotype. Entrance of peripheral B and T cells into the thymus has been described in healthy and pathological situations. However, it has not been proposed that leukocyte recirculation to the thymus could be a common feature occurring during the early phase of a Th1 inflammatory/infectious process when a large number of peripheral cells acquire an activated phenotype and the cellularity of the thymus is seriously compromised. The data we present here demonstrate that in well-established Th1 models triggered by different types of immunogens, for example, LPS treatment (a bacterial product), Candida albicans infection (a fungus), and after Trypanosoma cruzi infection (a parasite), a large number of mature peripheral B and T cells enter the thymus. This effect is dependent on, but not exclusive of, the available space in the thymus. Our data also demonstrate that MCP-1/CCR2 (where MCP-1 is monocyte chemoattractant protein-1) interaction is responsible for the infiltration of peripheral cells to the thymus in these Th1-inflammatory/infectious situations. Finally, systemic expression of IL-12 and IL-18 produced during the inflammatory process is ultimately responsible for these migratory events.
authors: Laboratory of Experimental Immunology, Cancer and Inflammation Program, Center for Cancer Research, Frederick National Laboratory for Cancer Research, NIH, Frederick, MD, USA.
authors: Deborah L
authors: DL
authors: Hodge
authors: Della
authors: D
authors: Reynolds
authors: Fabio M
authors: FM
authors: Cerbán
authors: Silvia G
authors: SG
authors: Correa
authors: Natalia S
authors: NS
authors: Baez
authors: Howard A
authors: HA
authors: Young
authors: Maria Cecilia
authors: MC
authors: Rodriguez-Galan
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology; D002176:Candida albicans / Q000276:immunology*; D002177:Candidiasis / Q000276:immunology*; D002465:Cell Movement; D002478:Cells, Cultured; D014355:Chagas Disease / Q000276:immunology*; D018932:Chemokine CCL2 / Q000378:metabolism*; D005260:Female; D018664:Interleukin-12 / Q000276:immunology; D020382:Interleukin-18 / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D011485:Protein Binding; D054390:Receptors, CCR2 / Q000378:metabolism*; D018417:Th1 Cells / Q000276:immunology* / Q000382:microbiology / Q000469:parasitology; D013950:Thymus Gland / Q000276:immunology / Q000473:pathology; D014349:Trypanosoma cruzi / Q000276:immunology*
chemical_list: C491768:Ccl2 protein, mouse; C515335:Ccr2 protein, mouse; D018932:Chemokine CCL2; D020382:Interleukin-18; D054390:Receptors, CCR2; D018664:Interleukin-12