Question

Dendritic cells are involved in cross-presentation of antigens. Which of the following protein(s) is(are) required for cross-presentation?
P. Basic leucine zipper ATF-like transcription factor 3 (BATF3)
Q. Membrane associated ring-CH-type finger 1 (MARCH-1)
R. Solute carrier family 10 member 1 (SLC10A1)
S. Class II-associated invariant chain peptide (CLIP)

• A. P only
• B. P and R only
• C. P, Q and R only
• D. S only

Hint:

Cross-presentation is key for CD8\(^+\) T cell priming.
BATF3-dependent dendritic cells are specialized for this function.

Answer 1

The Correct Option is A

Step 1: Cross-presentation is the ability of dendritic cells to present exogenous antigens on MHC class I molecules to CD8\(^+\) T cells.
Step 2: BATF3 (P) is a transcription factor crucial for the development of CD8\(^+\) dendritic cells that specialize in cross-presentation. Hence, BATF3 is required.
Step 3: MARCH-1 (Q) regulates MHC class II trafficking, not directly involved in cross-presentation.
Step 4: SLC10A1 (R) is a bile acid transporter, irrelevant to cross-presentation.
Step 5: CLIP (S) is associated with MHC class II antigen presentation, not cross-presentation.
Therefore, only BATF3 is essential. Correct answer is (A).