Which is not a type of T-lymphocyte?

Options

A. Helper
B. Suppressor
C. Cytotoxic
D. Repressor

Answer

**Step-by-Step Solution:**

1. **Understanding T-Lymphocytes**: T-lymphocytes, also known as T-cells, are a type of white blood cell that plays a crucial role in the immune response, specifically in cell-mediated immunity. This type of immunity does not involve the production of antibodies.

2. **Types of T-Lymphocytes**: There are several types of T-lymphocytes, including:
- **Helper T-cells (Th cells)**: These cells assist other immune cells in the immune response.
- **Cytotoxic T-cells (Tc cells)**: These cells are responsible for killing virus-infected cells and tumor cells.
- **Suppressor T-cells (also known as Regulatory T-cells)**: These cells help maintain immunological tolerance and prevent autoimmune responses.

3. **Identifying the Incorrect Option**: The question asks for a type that is *not* a T-lymphocyte. The options provided include:
- Helper T-cells
- Suppressor T-cells
- Cytotoxic T-cells
- **Repressor cells** (which is not a recognized type of T-lymphocyte).

4. **Conclusion**: Among the options listed, "repressor cells" is not a type of T-lymphocyte. Therefore, the correct answer is "repressor cells."

**Final Answer**: Repressor cells are not a type of T-lymphocyte.

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