What is the function of cytotoxic T cells?

Options

A. 1)They activate B cells
B. 2)They produce antibodies
C. 3)They phagocytize pathogens
D. 4)They lyse virus-infected cells

Answer

**Step-by-Step Solution:**

1. **Understanding Cytotoxic T Cells**: Cytotoxic T cells, also known as CD8+ T cells, are a type of immune cell that plays a crucial role in the body's defense against infections and cancer.

2. **Function of Cytotoxic T Cells**: The primary function of cytotoxic T cells is to identify and destroy cells that are infected by viruses or have become cancerous. They do this through a process known as lysis.

3. **Analyzing the Options**:
- **Option 1: They activate B-cells**: This is incorrect. B-cells are activated by helper T cells, not cytotoxic T cells.
- **Option 2: They produce antibodies**: This is also incorrect. Antibody production is the function of B-cells, not T-cells.
- **Option 3: They phagocytize pathogens**: This is incorrect as well. Phagocytosis is primarily performed by other white blood cells, such as neutrophils and macrophages.
- **Option 4: They lyse virus-infected cells**: This is the correct answer. Cytotoxic T cells release perforins and granzymes that lead to the destruction of infected or cancerous cells.

4. **Conclusion**: Therefore, the function of cytotoxic T cells is to lyse virus-infected cells.

**Final Answer**: Cytotoxic T cells primarily function to lyse virus-infected cells.

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