Final answer:
HIV uses the CD4 receptor, a glycoprotein on T lymphocytes, as its attachment molecule when infecting cells. The CD4 receptor facilitates the initial binding and subsequent entry of the virus into the host immune cell.
Step-by-step explanation:
Attachment Molecule of HIV During Infection
When infecting cells, the virus known as HIV (Human Immunodeficiency Virus) uses a specific glycoprotein to attach to its host cells. This molecule is critical for the virus to bind tightly to the surface of the immune cells it infects. In the case of HIV, the CD4 receptor, a glycoprotein found on the surfaces of T lymphocytes, serves as the attachment molecule. This interaction is the first step in the virus's complex replication process.
HIV is described as an enveloped, icosahedral virus that, upon attaching to the CD4 receptor, fuses with the immune cell membrane. Following this fusion, HIV releases its contents into the host cell, and viral enzymes then convert the single-stranded RNA genome into DNA, which is subsequently incorporated into the host genome. CD4 is not just a viral receptor; it is a cell adhesion molecule that plays a significant role in the immune response by facilitating communication between different types of immune cells.
Understanding the interaction between HIV and the CD4 receptor is important for the development of treatments and preventive measures against HIV/AIDS. The use of glycoproteins like the CD4 receptor by viruses such as HIV is a prime example of how viruses have evolved to exploit host cell mechanisms to their advantage.