Which one of the following statements about dendritic cells is true?
A)Immature dendritic cells are ubiquitously present in skin and mucosal tissues.
B)Dendritic cell maturation occurs after migration to lymph nodes in response to signals derived from activated T cells.
C)Class II MHC and T cell costimulators are highly expressed on immature dendritic cells and are down-regulated during maturation.
D)Dendritic cells that enter lymph nodes through draining lymphatics migrate to the B cell-rich follicles in response to chemokines.
E)The principal function of mature dendritic cells is antigen capturE.

Question

Quizplus · Accepted Answer

Tissues that are barriers between the external environment and the inside of the body,such as skin and mucosa,are rich in resting dendritic cells.In this location,the dendritic cells are well positioned to internalize samples of the environment and respond to innate immune system signals,which will drive their maturation into competent antigen-presenting cells.Dendritic cell maturation occurs during migration from infected tissues via lymphatics to the T cell zones of draining lymph nodes.Maturation must occur before,and is required for,activation of T cells,not vice versa.Class II MHC molecule up-regulation occurs during dendritic cell maturation and is one of the changes that make mature dendritic cells better able to present antigen to CD4⁺ T.

Which One of the Following Statements About Dendritic Cells Is