Lysis of foreign cells is mediated through

Options

A. IgM
B. IgA
C. IgM and IgG
D. ID and IgE

Answer

### Step-by-Step Solution:

1. **Understanding the Role of Antibodies**: Antibodies are proteins produced by the immune system to identify and neutralize foreign objects like bacteria and viruses. The primary antibodies involved in the lysis of foreign cells are Immunoglobulin M (IgM) and Immunoglobulin G (IgG).

2. **Identifying IgM**: IgM is the largest antibody and is the first to respond during the initial exposure to an antigen. It plays a crucial role in the immune response by binding to the complement components.

3. **Activation of the Classical Pathway**: When IgM binds to the complement components, it activates the classical pathway of the complement system. This activation leads to the opsonization of the antigen, which is a process that marks the pathogen for destruction.

4. **Lysis of Foreign Cells**: The activation of the complement system by IgM ultimately results in the lysis (destruction) of foreign cells. This means that IgM is directly responsible for the lysis of these cells.

5. **Identifying IgG**: IgG is the most abundant antibody in circulation and is produced by plasma B cells. While IgM is important for the initial response, IgG also plays a significant role in the immune response.

6. **Role of IgG in Lysis**: IgG can bind to pathogens and facilitate their recognition and ingestion by phagocytic immune cells, contributing to the lysis of foreign cells.

7. **Conclusion**: Both IgM and IgG are responsible for the lysis of foreign cells. Therefore, the correct answer to the question is that the lysis of foreign cells is mediated through both IgM and IgG.

### Final Answer:
The lysis of foreign cells is mediated through **IgM and IgG**.

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