Which of these cells are known to regulate cell-mediated immunity in the human body?

Options

A. helper B-cells
B. killer B-cells
C. suppressor cells
D. suppressor T-cells

Answer

To solve the question regarding which cells regulate cell-mediated immunity in the human body, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Cell-Mediated Immunity**:
- Cell-mediated immunity is a type of immune response that does not involve antibodies. Instead, it relies on the direct action of immune cells to combat pathogens.

**Hint**: Remember that cell-mediated immunity is distinct from humoral immunity, which involves antibodies.

2. **Identify Key Cells**:
- The primary cells involved in cell-mediated immunity are T-cells. These cells originate from the thymus and play a crucial role in identifying and destroying infected or cancerous cells.

**Hint**: T-cells are essential for cell-mediated immunity, while B-cells are primarily involved in humoral immunity.

3. **Differentiate Between T-Cells**:
- Within T-cells, there are different types including Helper T-cells, Cytotoxic T-cells, and Suppressor T-cells.
- Helper T-cells assist other immune cells, Cytotoxic T-cells kill infected cells, and Suppressor T-cells help regulate the immune response and prevent autoimmunity.

**Hint**: Focus on the function of each type of T-cell to determine their role in immunity.

4. **Evaluate the Role of Suppressor T-Cells**:
- Suppressor T-cells (also known as Regulatory T-cells) help to prevent autoimmune diseases by inhibiting the immune response against the body’s own cells. However, they are not the primary regulators of cell-mediated immunity against foreign pathogens.

**Hint**: While suppressor T-cells play a role in regulating the immune response, they are not the main players in attacking foreign invaders.

5. **Conclusion**:
- Based on the information, while T-cells are crucial for cell-mediated immunity, the specific mention of Suppressor T-cells in the question suggests that they are the focus here. Therefore, if the question asks specifically about the regulation of cell-mediated immunity, the answer would be Suppressor T-cells, as they help modulate the immune response.

**Final Answer**: Suppressor T-cells.