CD8

noun

ˌsē-(ˌ)dē-ˈāt 

: a glycoprotein that is found associated with a T cell receptor especially on the surface of a cytotoxic T cell and that binds to a major histocompatibility complex molecule on the surface of an antigen-presenting cell to facilitate antigen recognition and cytotoxic T cell activation

—often used before another noun

CD8 surface markers

CD8 cells [=cells bearing CD8 on their surface]

… the CD8 molecule is closely associated with MHC class I molecules on antigen-presenting cells.

—Scientific American Medicine

compare CD4

Examples of CD8 in a Sentence

Recent Examples on the Web

Using data on known CD8+ T cell epitopes – small fragments of viral proteins the immune cell can identify – the researchers found that around 60% of people would likely have some degree of pre-existing immunity to H5N1 due to CD8+ T cell virus recognition. —New Atlas, 24 Feb. 2025

Go deeper: Hamadeh wins CD8 Republican primary Slugfest between Hamadeh and Masters dominates CD8 Republican primary 9th Congressional District: Paul Gosar (R) Longtime Rep. Paul Gosar is running unopposed in his district, which encompasses parts of the West Valley and northwestern Arizona. —Jessica Boehm, Axios, 9 Oct. 2024

Masters was chief operating officer of Thiel Capital and president of the nonprofit Thiel Foundation. Catch up quick: The CD8 winner will replace outgoing U.S. Rep. Debbie Lesko, a Republican who first won the seat in a 2018 special election. —Jeremy Duda, Axios, 30 July 2024

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

In the last few years, some in the field have thought tumor-fighting CD8+ T cells come in to suppress the disease-causing immune response of CD4+ cells. —Isabella Cueto, STAT, 14 July 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 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

More intriguing, most of these active mice had been inoculated with cancer cells that are known to be particularly vulnerable to a specific type of immune cell, known as CD8+ T cells, which tend, primarily, to fight certain forms of breast cancer and other solid tumors. —Gretchen Reynolds, Star Tribune, 21 Nov. 2020

Word History

First Known Use

1984, in the meaning defined above

Medical Definition

CD8

noun

ˌsē-(ˌ)dē-ˈāt 

: a glycoprotein that is found associated with a T cell receptor especially on the surface of a cytotoxic T cell and that binds to a major histocompatibility complex molecule on the surface of an antigen-presenting cell to facilitate antigen recognition and cytotoxic T cell activation

—often used before another noun

CD8 surface markers

CD8 cells [=cells bearing CD8 on their surface]

… the CD8 molecule is closely associated with MHC class I molecules on antigen-presenting cells.

—Scientific American Medicine

compare cd4