Which of the following is not an antigen presenting cell?

Options

A. B-cell
B. Macrophage
C. Dendritic cell
D. T-cell

Answer

To determine which of the following is not an antigen presenting cell (APC), we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Antigen Presenting Cells (APCs)**:
- APCs are immune cells that process and present antigens to T cells, initiating an immune response. They include various types of cells that play a crucial role in the adaptive immune system.

2. **Analyzing Option 1: B Cells**:
- B cells are a type of lymphocyte that can act as APCs. They can present antigens to T helper cells and are involved in the production of antibodies. Therefore, B cells are indeed APCs.

3. **Analyzing Option 2: Macrophages**:
- Macrophages are large phagocytic cells that engulf and digest pathogens. They also present antigens to T cells and are considered one of the primary APCs in the immune response. Thus, macrophages are APCs.

4. **Analyzing Option 3: Dendritic Cells**:
- Dendritic cells are highly effective APCs. They capture and present antigens to T cells, playing a vital role in the initiation of the immune response. Hence, dendritic cells are also classified as APCs.

5. **Conclusion**:
- Since B cells, macrophages, and dendritic cells are all antigen presenting cells, we need to identify the option that is not an APC. If there is an option that does not belong to this category, it would be the correct answer.

6. **Final Answer**:
- Based on the analysis, if the options provided included a cell type that is not involved in antigen presentation (such as a red blood cell or a type of epithelial cell), that would be the answer. However, since the question does not provide those options, we conclude that all the mentioned cells (B cells, macrophages, dendritic cells) are APCs.