Activation of naive T cells – Pathology MCQ

The most potent activators of naive T cells?
A. Eosinophils
B. Macrophages
C. B lymphocytes
D. Mature dendritic cells

Correct answer : D. Mature dendritic cells

Dendritic (Langerhans) cells in the epidermis. (M. ulcerans infection, S100 immunoperoxidase stain)

• Activation of T cells need 2 sets of signals
  • T cell receptor complex (TCR with CD4+ or CD8+) on the T cells should bind with the Major Histocompatibility Complex (MHC) on the Antigen Presenting Cells (APC).
  • Non specific costimulatory signal due to the interaction of the costimulators present on the antigen presenting cells.
• Mature dendritic cells have the highest number of costimulators.
• Therefore, they are the most potent activators of naive T cells.