Co-stimulatory functions of antigen-presenting cells.
Antigen-presenting cells, in addition to presenting processed antigen, provide co-stimulatory signals that are necessary for stimulating maximal lymphokine production by CD4+ T cells. For interleukin 2 (IL-2)-producing CD4+ T cells, the B7 molecule provides an important co-stimulatory signal through interaction with its ligand on the T-cell surface, CD28. Populations of antigen-presenting cells that express high levels of B7 (e.g., dendritic cells) are much more potent stimulators of T-cell activation than cells that fail to express B7 (e.g., resting B cells). An increase in B7 expression could therefore explain the increased accessory function gained by Langerhans cells as they leave the skin and migrate to the draining lymph node.
Department of Microbiology, University of Minnesota Medical School, Minneapolis 55455.
J G
JG
Johnson
M K
MK
Jenkins
D000938:Antigen-Presenting Cells / Q000502:physiology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation