Function
CD81 is a cell-surface protein involved in a variety of biological responses like adhesion, morphology, activation, proliferation and differentiation of of B- and T-cells[1]. CD81 belongs to the tetraspanin family - protein containing 4 transmembrane domains - which form microdomains in the cell surface with a variety of partner proteins.
Relevance
CD81 is widely expressed on the majority of tumor cells. Antibodies that target CD81 are a novel treatment against B-cell lymphoma[2]. CD81-defficient mice are impaired in their ability to suppress the anti-tumor immune response.
Structural highlights
The structure of the complex of human CD81 with mouse antibody shows interactions of the CD81 helix D with the antibody heavy chain and CD81 residues in helix C with the light chain[3].
- ↑ Levy S, Todd SC, Maecker HT. CD81 (TAPA-1): a molecule involved in signal transduction and cell adhesion in the immune system. Annu Rev Immunol. 1998;16:89-109. doi: 10.1146/annurev.immunol.16.1.89. PMID:9597125 doi:https://dx.doi.org/10.1146/annurev.immunol.16.1.89
- ↑ Vences-Catalan F, Kuo CC, Rajapaksa R, Duault C, Andor N, Czerwinski DK, Levy R, Levy S. CD81 is a novel immunotherapeutic target for B cell lymphoma. J Exp Med. 2019 Jul 1;216(7):1497-1508. doi: 10.1084/jem.20190186. Epub 2019 May , 23. PMID:31123084 doi:https://dx.doi.org/10.1084/jem.20190186
- ↑ Susa KJ, Seegar TC, Blacklow SC, Kruse AC. A dynamic interaction between CD19 and the tetraspanin CD81 controls B cell co-receptor trafficking. Elife. 2020 Apr 27;9. pii: 52337. doi: 10.7554/eLife.52337. PMID:32338599 doi:https://dx.doi.org/10.7554/eLife.52337