Memory T cells can be identified by using the following marker?
**Core Concept**
The question is testing the student's knowledge of immunological markers, specifically those used to identify memory T cells. Memory T cells are a type of T lymphocyte that remembers past infections, allowing for a rapid and effective response upon re-exposure to the same antigen.
**Why the Correct Answer is Right**
Although the correct answer is not provided, typically, memory T cells are identified by markers such as CD45RO. This marker is expressed on the surface of memory T cells, distinguishing them from naive T cells, which express CD45RA. The expression of CD45RO is associated with the transition of naive T cells to memory T cells after antigen exposure.
**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific details of option A, it's challenging to provide a precise explanation for its incorrectness. However, common incorrect markers for memory T cells might include those that are not exclusively or predominantly expressed on memory T cells.
**Option B:** Similarly, without knowing what option B entails, we can speculate that it might be incorrect if it represents a marker for a different subset of immune cells or a marker not specifically associated with memory function.
**Option C:** This option would be incorrect for the same reasons as options A and B, assuming it does not represent a known marker for memory T cells.
**Option D:** Again, lacking the specifics, if option D is not a recognized marker for memory T cells, such as CD45RO, it would be an incorrect choice.
**Clinical Pearl / High-Yield Fact**
Memory T cells play a crucial role in long-term immune memory, enabling the body to mount a swift and potent response to previously encountered pathogens. Recognizing the markers that identify these cells is essential for understanding immune responses and developing diagnostic and therapeutic strategies.
**Correct Answer:** Correct Answer: D. CD45RO.