CD86

Also called B7-2

T cells need two signals for activation - the first signal is antigen peptide presented on MHC class II through the T cell receptor

The second (costimulatory) signal is delivered by CD80 or CD86, expressed on surface of antigen presenting cells, which interact with either CD28 or CD152 (CTLA-4)

CD80 and CD86 appear to have opposing functions on regulatory T cells (J Immunol 2004;172:2778)

Polymorphisms are associated with liver transplant acceptance (Transpl Immunol 2005;15:69) and systemic sclerosis (Int J Immunogenet 2006;33:155)

Increased expression may cause excessive antigen presentation in fulminant hepatic failure as an early step in its pathogenesis before the onset of tissue damage (Am J Pathol 1999;154:1711)

High circulating soluble levels are poor prognostic factor in myeloma (Br J Haematol 2006;133:165); are associated with severe asthma (Thorax 2004;59:870)

Receptor for some adenovirus species (Virus Res 2006;122:144)

Associated with H. pylori dependent early stage high grade MALT lymphoma of stomach (World J Gastroenterol 2005;11:4357)

Uses: no significant clinical use by pathologists

Diagram: costimulatory signal

Micro images: inflamed skin; fulminant hepatic failure; chronic HBV infection of liver; liver sinusoidal endothelial cells; thyroid carcinoma (E-H); normal esophagus; esophageal carcinoma

early stage high grade gastric MALT lymphoma - H. pylori dependent case (CD86+); H. pylori independent case (CD86-)

Positive staining (normal): interdigitating dendritic cells in T zones of secondary lymphoid organs, Langerhans cells, peripheral blood dendritic cells, memory B cells, germinal center B cells, monocytes, endothelial cells, activated T cells

Positive staining (disease): AML (29%, Clin Cancer Res 2005;11:5708), ulcerative colitis (100%, Dig Dis Sci 2004;49:1738)

Negative staining: immature dendritic cells

References: OMIM 601020