Question

Which of the following statements is false regarding regulatory T cells?

a. Their suppression of a T cell requires both T cells to interact with the same APC.
b. They express the transcriptional repressor FoxP3.
c. They possess TCRs specific for self-antigens.
d. They are distinguished from other CD4 T cells by the expression of CD2.
e. None of the above are false, they are all true statements.

Answer 1

The false statement about regulatory T cells is that they are distinguished by the expression of CD2. Regulatory T cells are actually identified by their expression of CD4, CD25, and FoxP3, with CD25 being a key distinguishing feature. Option d is correct.

Step-by-step explanation:

The false statement regarding regulatory T cells (Treg) is option d.

Regulatory T cells, also known as suppressor T cells, are a crucial component of the immune system and help suppress immune responses to prevent autoimmune diseases. They are characterized by their expression of CD4, CD25, and the transcriptional repressor FoxP3. They do have TCRs (T cell receptors) specific for antigens, including self-antigens, which is essential for their function in immune tolerance and the suppression of inappropriate immune responses.

However, the statement about CD2 is incorrect because regulatory T cells are distinguished by their high expression of CD25 (the alpha chain of the IL-2 receptor), not CD2. CD2 is a molecule found on the surface of all T cells and is not specific to regulatory T cells. Therefore, the correct answer is:
e. None of the above are false, they are all true statements is the incorrect option, as the other statements (a, b, c) are all true characteristics of regulatory T cells.