Regulatory T cells can migrate to follicles upon T cell activation and suppress GC-Th cells and GC-Th cell-driven B cell responses.
How Tregs migrate to GCs, and whether they regulate the helper activity of the T cells in GCs (GC-Th cells) remains poorly understood. We found a T cell subset in human tonsils that displays potent suppressive activities toward GC-Th cell-dependent B cell responses. These Tregs with the surface phenotype of CD4+CD25+CD69- migrate well to CCL19, a chemokine expressed in the T cell zone, but poorly to CXCL13, a chemokine expressed in the B cell zone. This migration toward the T cell-rich zone rapidly changes to trafficking toward B cell follicles upon T cell activation. This change in chemotactic behavior upon activation of T cells is consistent with their switch in the expression of the 2 chemokine receptors CXCR5 and CCR7. CD4+CD25+CD69- Tregs suppress GC-Th cells and GC-Th cell-induced B cell responses such as Ig production, survival, and expression of activation-induced cytosine deaminase. Our results have identified a subset of Tregs that is physiologically relevant to GC-Th cell-dependent B cell responses and a potential regulation mechanism for the trafficking of these Tregs to GCs.
Lim
Hyung W
HW
Laboratory of Immunology and Hematopoiesis, Department of Pathobiology, Purdue University, West Lafayette, Indiana 47907, USA.
Hillsamer
Peter
P
Kim
Chang H
CH
D015703:Antigens, CD / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology; D002465:Cell Movement / Q000502:physiology*; D018925:Chemokines / Q000378:metabolism; D006801:Humans; D007107:Immune System / Q000502:physiology*; D008213:Lymphocyte Activation; D014066:Palatine Tonsil / Q000166:cytology* / Q000276:immunology; D019707:Receptors, Chemokine / Q000378:metabolism; D016176:T-Lymphocyte Subsets; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D015703:Antigens, CD; D018925:Chemokines; D019707:Receptors, Chemokine