Gamma interferons stimulate

Options

A. Metastasis
B. Hypersensitivity
C. Fever response
D. Erythropoiesis

Answer

### Step-by-Step Solution:

1. **Understanding Gamma Interferons**:
- Gamma interferons are a type of interferon, which are proteins released by virus-infected cells. Their primary role is to protect neighboring cells from viral infections.

2. **Function of Interferons**:
- Interferons, including gamma interferons, are involved in the immune response. They help to inhibit viral replication and enhance the immune response against tumors.

3. **Characteristics of Gamma Interferons**:
- Gamma interferons are described as pleiotropic, meaning they can have multiple effects and can exist in different forms. They exhibit both antiviral and antitumor properties.

4. **Role in Immune Response**:
- One of the key functions of gamma interferons is to stimulate macrophages. Macrophages are a type of white blood cell that play a crucial role in the immune system by engulfing and digesting pathogens.

5. **Macrophage Activation**:
- When stimulated by gamma interferons, macrophages become more effective at killing pathogens. They release toxic substances that help to eliminate these invaders.

6. **Fever Response**:
- The release of toxic elements by activated macrophages can also lead to a fever response. Fever is a systemic response that helps the body fight infections by creating an environment less favorable for pathogens.

7. **Evaluating the Options**:
- The question asks what gamma interferons stimulate. The options include metastasis, hypersensitivity, erythropoiesis, and fever response.
- **Metastasis**: This refers to the spread of cancer cells, which gamma interferons do not promote as they have antitumor properties.
- **Hypersensitivity**: This is an exaggerated immune response, which is not directly stimulated by gamma interferons.
- **Erythropoiesis**: This is the formation of red blood cells, which is not a function of gamma interferons.
- **Fever Response**: This is indeed stimulated by gamma interferons through the activation of macrophages.

8. **Conclusion**:
- Therefore, the correct answer is that gamma interferons stimulate the fever response.