Gp 120 of HIV interacts with target cell through

Options

A. `CD_8` receptor
B. `CD_4` receptor
C. `G_(p_41)`
D. Both (2) & (3)

Answer

To solve the question regarding how Gp120 of HIV interacts with target cells, we can break down the process step by step:

### Step-by-Step Solution:

1. **Understanding Gp120**: Gp120 is a glycoprotein found on the surface of the HIV virus. It plays a crucial role in the virus's ability to infect host cells.

**Hint**: Remember that Gp120 is a protein that helps the virus attach to host cells.

2. **Identifying Target Cells**: The primary target cells for HIV are the immune cells, specifically the helper T-cells (also known as CD4+ T-cells) and macrophages. These cells have specific receptors that the virus can bind to.

**Hint**: Focus on the types of immune cells that are most affected by HIV.

3. **Receptor Interaction**: Gp120 interacts specifically with the CD4 receptor present on the surface of helper T-cells and macrophages. This interaction is essential for the virus to gain entry into these cells.

**Hint**: Think about the importance of receptors in cellular interactions and how viruses exploit them.

4. **Mechanism of Entry**: Once Gp120 binds to the CD4 receptor, it triggers a conformational change that allows the virus to fuse with the cell membrane, leading to the entry of the viral genetic material into the host cell.

**Hint**: Consider how binding to a receptor can change the behavior of both the virus and the host cell.

5. **Consequences of Infection**: After entering the cell, HIV can replicate and ultimately lead to the destruction of the T-cells, which weakens the immune response and makes the body more susceptible to infections.

**Hint**: Reflect on the implications of HIV infection on the immune system and overall health.

### Final Answer:
Gp120 of HIV interacts with target cells through the CD4 receptor found on helper T-cells and macrophages.