Question

The primary function of the class I and class II MHC molecules is:

• A. binding peptide antigens for recognition by antigen-specific receptors on T-cells
• B. mediation of T-independent B-cell responses
• C. helping in endocytosis of antigens by phagocytic cells
• D. aid opsonization of foreign particle

Hint:

MHC = "Display Platters" for T-cells to taste.

Answer 1

The Correct Option is A

Step 1: Concept
The Major Histocompatibility Complex (MHC) is a set of surface proteins essential for the adaptive immune system.

Step 2: Meaning
MHC molecules act as "display cases" that present small pieces of proteins (peptides) to the immune system.

Step 3: Analysis
MHC Class I presents endogenous antigens to CD8+ T-cells, while MHC Class II presents exogenous antigens to CD4+ T-cells. Without this presentation, T-cell receptors (TCRs) cannot "see" or recognize the antigens hidden inside or around cells.

Step 4: Conclusion
Their primary biological role is antigen presentation for T-cell recognition. Final Answer: (A)