Identification of dendritic cells as a major source of interleukin-6 in draining lymph nodes following skin sensitization of mice.
Skin sensitization with chemical allergens is associated with the activation and proliferation of T lymphocytes within lymph nodes draining the site of exposure. These events are accompanied by the secretion of interleukin-6 (IL-6) by lymph node cells (LNC). We have investigated the cellular source of IL-6 seventy-two hours following primary exposure of mice to the contact allergen oxazolone. Immunocytochemical analyses of sections of activated lymph nodes have revealed that cells expressing IL-6 are located within the T-dependent lymph node paracortex, with none present in lymphoid follicles. Cells which expressed IL-6 cofractionated exclusively with LNC of low buoyant density, the majority of which also expressed membrane Ia and had a dendritic morphology. Depletion of dendritic cells from LNC culture was associated with a significant decrease in the secretion of IL-6 by the residual population. These data demonstrate that dendritic cells are a major source of IL-6 within lymph nodes during primary immune responses to cutaneous antigens.
University of Manchester Rheumatic Diseases Centre, Hope Hospital, Salford, UK.
J C
JC
Hope
M
M
Cumberbatch
I
I
Fielding
R J
RJ
Dearman
I
I
Kimber
S J
SJ
Hopkins
D000818:Animals; D003713:Dendritic Cells / Q000276:immunology*; D017449:Dermatitis, Allergic Contact / Q000276:immunology*; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000378:metabolism*; D008198:Lymph Nodes / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008807:Mice, Inbred BALB C; D010081:Oxazolone
D015850:Interleukin-6; D010081:Oxazolone