major histocompatibility complex

noun

plural major histocompatibility complexes

: a group of genes in mammals that code for cell-surface polymorphic glycoprotein molecules which display antigenic peptide fragments for T cell recognition and aid in the ability of the immune system to determine self from nonself

Note: The genes of the major histocompatibility complex and the molecules they determine are grouped into 2 classes. Glycoprotein molecules of class I are expressed on all nucleated cells and are recognized by CD8 on the surface of cytotoxic T cells. Glycoprotein molecules of class II are restricted to antigen-presenting cells and are recognized by CD4 on the surface of helper T cells.

—often used before another noun

major histocompatibility complex molecules

—abbreviation MHC compare HLA

Examples of major histocompatibility complex in a Sentence

Recent Examples on the Web

They’ve been bred to lack proteins — members of a family called MHCI (which stands for major histocompatibility complex class I) — crucial to fighting pathogens. —Kenneth Miller, Discover Magazine, 10 Dec. 2013

After taking swabs from mandrill sternal glands, researchers genotyped each sample to determine the monkey's major histocompatibility complex (MHC)--a unique genetic signature related to the animal's immune system. —Joseph Calamia, Discover Magazine, 5 Aug. 2010

Communication by smell comes down to a thing called the major histocompatibility complex, or MHC. —Breanna Draxler, Discover Magazine, 24 Jan. 2013

The two year old Patient 2 was seeking the same treatment for another rare immune disease, major histocompatibility complex class II deficiency, which is considered a variant of SCID. —Rebecca Kreston, Discover Magazine, 28 Apr. 2016

These molecular identity cards are produced by a set of genes collectively known as the major histocompatibility complex, or MHC. —Julie Rehmeyer, Discover Magazine, 31 Mar. 2014

Scientists have long known, for example, that children inherit a wider variety of immune defenses when their parents differ greatly in a group of genes called the major histocompatibility complex (MHC). —Arthur C. Brooks, The Atlantic, 10 Feb. 2022

Finally, in Orf8, which downregulates the major histocompatibility complex (MHC-I), the researchers note H17Y and G8stop. —William A. Haseltine, Forbes, 22 Oct. 2021

What Pheramor is actually comparing are 11 genes of the major histocompatibility complex (MHC), which code for proteins on the surface of cells that help the immune system recognize invaders. —Jackie Mansky, Smithsonian, 15 Feb. 2018

Word History

First Known Use

1972, in the meaning defined above

Medical Definition

major histocompatibility complex

noun

: a group of genes in mammals that function especially in determining the histocompatibility antigens found on cell surfaces and that in humans comprise the alleles occurring at four loci on the short arm of chromosome 6

Note: The genes of the major histocompatibility complex and the histocompatibility antigens they determine are grouped into 2 classes. Glycoprotein molecules of class I are expressed on all nucleated cells and are recognized by CD8 on the surface of cytotoxic T cells. Glycoprotein molecules of class II are restricted to antigen-presenting cells and are recognized by CD4 on the surface of helper T cells.

—often used before another noun

major histocompatibility complex molecules

—abbreviation MHC compare hla