Human Immunodeficiency Virus (HIV) Infection


Attachment to the Lymphocyte Membrane


 

On the surface membrane of all living cells are complex protein structures called "receptors". A receptor is often compared to a lock into which a specific key or "ligand" will fit. There are at least two receptors on T-lymphocytes to which the human immunodeficiency virus (HIV) sticks. The primary receptor, called "CD4", is shown on the right in the diagram. But a second receptor that loops through the cell membrane 7 times is critical for infection to occur.

HIV infection of a lymphocyte requires attachment of the virus to the cell membrane through both of these "ligand-receptor" links. In cells whose "7-transmembrane receptor" is different, the HIV "key" no longer matches the lymphocyte "lock" and attachment is incomplete. Those cells may avoid infection by HIV.


Entry of the Viral RNA


 


Return to Overview of HIV Infection.

HIV Infection Diagram

1. ATTACHMENT
Getting in

2. REVERSE TRANSCRIPTION
From viral RNA to DNA

3. INTEGRATION, TRANSCRIPTION
a. Viral DNA joins host DNA
b. Making multiple viral RNAs

4. TRANSLATION
Producing viral proteins

5. VIRAL PROTEASE
Cleaving viral proteins

6. ASSEMBLY & BUDDING
Getting out