Antibodies that function in innate immunity are

Options

A. IgM
B. IgE
C. IgA
D. IgD

Answer

**Step-by-Step Text Solution:**

1. **Understanding Innate Immunity**: Innate immunity is the body's first line of defense against invading pathogens. It provides immediate, non-specific responses to infections.

2. **Identifying Antibodies**: The question asks about antibodies that function specifically in innate immunity. We need to evaluate the different types of antibodies (IgM, IgE, IgA, and IgD) to determine which one is involved in innate immunity.

3. **Evaluating IgM**:
- IgM is the largest antibody and is primarily involved in the adaptive immune response.
- It activates when a virus attacks, thus it is not considered part of innate immunity.
- **Conclusion**: IgM is an incorrect option.

4. **Evaluating IgE**:
- IgE is found only in mammals and is synthesized by plasma cells.
- It plays a crucial role in hypersensitivity reactions, including allergic diseases.
- **Conclusion**: IgE is also an incorrect option for innate immunity.

5. **Evaluating IgA**:
- IgA is important for immune functions in mucous membranes, which are part of the body's first line of defense.
- It plays a significant role in protecting against pathogens at mucosal surfaces.
- **Conclusion**: IgA is the correct option as it functions in innate immunity.

6. **Evaluating IgD**:
- IgD is primarily involved in the activation of B-cells.
- It does not play a direct role in innate immunity.
- **Conclusion**: IgD is an incorrect option.

7. **Final Answer**: The antibody that functions in innate immunity is **IgA**.

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