Question

Naive T lymphocytes can be stimulated by the activated dendritic cells that bear

• A. a specific antigenic peptide alone
• B. a specific antigenic peptide and CD11c
• C. a combination of co-stimulatory molecules and a non-specific antigenic peptide
• D. a combination of co-stimulatory molecules and a specific antigenic peptide

Hint:

For T cell activation, both antigen presentation and co-stimulation are required.

Answer 1

The Correct Option is D

Step 1: T Lymphocyte Activation.
For T lymphocytes to be activated, they need two signals: one from the antigenic peptide presented by the dendritic cell, and the other from co-stimulatory molecules.
Step 2: Role of Co-stimulatory Molecules.
Co-stimulatory molecules, such as B7 on the dendritic cells, interact with the CD28 receptor on the T cell to provide the second necessary signal for activation. Without these co-stimulatory signals, the T cell will not be fully activated.
Step 3: Conclusion.
Thus, naive T lymphocytes are activated by a combination of a specific antigenic peptide and co-stimulatory molecules, making the correct answer (D).