GLOSSARY

B

• B7-2 (CD86) #

  Alternative names:

  • Human: B7-2/B70, LAB72, MGC34413, CD28LG2
  • Murine: B7-2/B70, Ly-58

  In humans and in mice, B7-2 can be found on the surface of: T cells, B cells, dendritic cells, macrophages/monocytes

  Ligands: CD28, CD152

  Function: Lymphocyte activation/costimulation, immunoregulation

  Additional information: B7-2 is also known as CD86. CD86 is a ligand for CD28 and CD152 receptor molecules found on the surface of T cells. While CD86 has a similar structure and function as CD80, there are considerable differences in their protein identity, implying different stimulatory mechanisms. The exact structural and functional differences between the two are not well understood, though studies show that CD86 plays a more critical role in T cell activation. CD86 is a costimulatory molecule necessary for T cell activation and for the prevention of T cell anergy. After the MHC presents the specific antigen stimulus, the binding of CD86 with CD28 on the T cell is the second stimulus that allows T cell activation, increased IL-2 cytokine production, proliferation, and differentiation. The two-step threshold is critical for maintaining self-tolerance and inhibiting T cell overactivity. After the T cell is activated, CD152 binds to CD86 to inhibit the effector T cell’s activity, regulating the immune response.

  Further reading:

  What’s the difference between CD80 and CD86? Sansom DM, et al. Trends in Immunology (2003)

• B7-H3 (CD276) #

  Alternative names: 4lg-B7-H3, B7RP-2

  B7-H3 can be found on the surface of:

  • Human: dendritic cells, macrophages/monocytes
  • Murine: dendritic cells, macrophages/monocytes, T cells, B cells, NK cells, epithelial cells

  Ligands: TLT-2

  Associated molecules: ICOS (CD278), CD28, CD152, CD26

  Function: immune regulation, immune checkpoint

  Additional information: B7-H3 is also known as CD276. It shows limited expression in healthy tissue and is overexpressed in tumor tissues. Increased surface expression of CD276 is correlated with tumor growth and immunosuppression by cancer cells. CD276 is, therefore, a target for immunotherapy research. CD276 has conflicting roles in immune regulation, acting as a costimulatory or co-inhibitory molecule for T cells, depending on the context.

  Further reading:

  B7-H3/CD276: An Emerging Cancer Immunotherapy. Zhou WT, Jin WL. Frontiers in Immunology (2021)