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

the CD4 gene

CD4 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.

compare CD8

Examples of CD4 in a Sentence

Recent Examples on the Web

Schoenberger said the next path of exploration is to explore ways that antigens that activate CD4 and CD8 T-cells could be linked. —Paul Sisson, San Diego Union-Tribune, 6 Mar. 2024

The enveloped and the lentiviral vector displayed CD3, CD4 and CD28-targeting antibody fragments on their surface to target T cells. —William A. Haseltine, Forbes, 14 Feb. 2024

There’s no shortage of follow-up questions to investigate: How exactly are all these immune cells getting activated by CD4+? —Isabella Cueto, STAT, 14 July 2023

In the cases where people had few CD4 cells, mpox’s normally small skin lesions grew into large necrotizing patches and their infection sometimes spread to the lungs or caused severe secondary infections with bacteria. —Bykai Kupferschmidt, science.org, 21 Feb. 2023

When the adaptive response starts taking effect, CD4+ and CD8+ T-cells are released which play an important role in coordinating a sustained immune response and killing off infected cells. —William A. Haseltine, Forbes, 13 Feb. 2023

The virus infects and destroys white blood cells called CD4+ cells, which weakens the immune system. —Ella Lee, USA TODAY, 13 Jan. 2022

The scientists looked for antibodies, memory B cells, CD8+ T cells, and CD4+ T cells, all fighting SARS-CoV-2. —Adam Rogers, Wired, 5 Mar. 2021

The disease would later be cataloged on immunological graphs illustrating the awful decline of the infected – first the CD4+ T-cell count falls as the viral load ascends, then a marching band of viral, fungal, protozoan and bacterial infections capitalizing on the loss of CD4+ T-cells. —Rebecca Kreston, Discover Magazine, 28 Sep. 2014

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

the CD4 gene

CD4 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.

compare cd8