What is the importance of the variable region of T-cell receptors?

• A. The variable region is the closest region to the cell's surface and stabilizes the receptor in the plasma membrane.
• B. The variable region directly binds to antigens.
• C. The variable region varies in its amino acid sequence allowing different TCRs to bind different antigens.
• D. The variable region directly binds to antibodies.
• E. A and B.
• F. B and C.
• G. C and D.

Answer: (F)

Verified step by step guidance

1. Understand the structure of T-cell receptors (TCRs). TCRs are composed of two chains, each having a constant and a variable region. The variable region is crucial for antigen recognition.
2. Recognize the role of the variable region in antigen binding. The variable region of TCRs is responsible for directly binding to antigens, allowing the immune system to recognize and respond to a wide array of pathogens.
3. Explore the diversity of the variable region. The amino acid sequence of the variable region varies greatly among different TCRs, enabling the immune system to generate a diverse repertoire of receptors that can bind to different antigens.
4. Clarify the misconception about antibody binding. TCRs do not bind directly to antibodies; instead, they interact with antigens presented by other cells, such as antigen-presenting cells.
5. Identify the correct statements. Based on the explanations, the correct importance of the variable region of TCRs is that it directly binds to antigens (B) and varies in its amino acid sequence allowing different TCRs to bind different antigens (C).