CCR6-dependent recruitment of blood phagocytes is necessary for rapid CD4 T cell responses to local bacterial infection.
The contribution of CCR6 and phagocyte recruitment to the initiation of T cell responses to a local pathogen is unclear. CD4 T cell activation to an injected soluble antigen occurred rapidly and was completely CCR6-independent. In marked contrast, the tempo of pathogen-specific CD4 T cell activation depended on whether the antigen was secreted or cell-associated. Furthermore, lymph node pathogen-specific CD4 T cell activation required CCR6 and cell migration from the site of infection. Surprisingly, adoptive transfer of wild-type blood phagocytes rescued bacteria-specific T cell activation in CCR6-deficient mice, even when these cells were unable to participate in direct antigen presentation. These data demonstrate that T cell responses to a local bacterial infection follow a distinct tempo, largely determined by bacterial protein secretion, and that CCR6-mediated blood phagocyte recruitment to the site of infection is a critical step in the initiation of pathogen-specific immune responses in skin draining lymph nodes.
Ravindran
Rajesh
R
Center for Infectious Diseases and Microbiology Translational Research, Department of Medicine, Division of Gastroenterology, Hepatology and Nutrition, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
Rusch
Lori
L
Itano
Andrea
A
Jenkins
Marc K
MK
McSorley
Stephen J
SJ
D019264:Adoptive Transfer; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000942:Antigens, Bacterial / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000382:microbiology; D002465:Cell Movement; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000166:cytology; D007249:Inflammation; D007700:Kinetics; D008198:Lymph Nodes / Q000166:cytology / Q000473:pathology; D008213:Lymphocyte Activation / Q000276:immunology; D051379:Mice; D010586:Phagocytes / Q000166:cytology* / Q000276:immunology* / Q000382:microbiology; D054399:Receptors, CCR6; D019707:Receptors, Chemokine / Q000172:deficiency / Q000276:immunology*; D012475:Salmonella; D012480:Salmonella Infections / Q000276:immunology*; D012995:Solubility
D000942:Antigens, Bacterial; C498126:CCR6 protein, mouse; D054399:Receptors, CCR6; D019707:Receptors, Chemokine