CD4
noun
ˌsē-(ˌ)dē-ˈfȯr 
: a large glycoprotein that is found associated with a T cell receptor especially on the surface of helper T cells and that binds to a major histocompatibility complex molecule on the surface of an antigen-presenting cell to facilitate antigen recognition and T cell activation —often used before another noun compare CD8
the CD4 geneCD4 T cells [=T cells bearing CD4 on their surface]
Note: CD4 is a receptor for HIV, and cells of the immune system bearing CD4 on their surface are preferentially infected with the virus and become progressively depleted.
Word History
Etymology
cluster of differentiation
First Known Use
1984, in the meaning defined above
Medical Definition
CD4
noun
-ˈfōr, -ˈfȯr
: a large glycoprotein that is found associated with a T cell receptor especially on the surface of helper T cells and that binds to a major histocompatibility complex molecule on the surface of an antigen-presenting cell to facilitate antigen recognition and T cell activation —often used before another noun compare cd8
the CD4 geneCD4 T cells [=T cells bearing CD4 on their surface]
Note: CD4 is a receptor for HIV and cells of the immune system bearing CD4 on their surface are preferentially infected with the virus and become progressively depleted.