CD8.4 is a murine chimeric coreceptor. The extracellular and transmembrane part of the coreceptor is from wild-type CD8 coreceptor, whereas the intracellular domain from CD4 coreceptor. [1]This model was created to examine role of coreceptor coupling to Lck (lymphocyte-specific protein tyrosine kinase)[1] as the CD4 and CD8 coreceptors have an Lck-binding site in their intracellular domain. CD4 coreceptor has higher coupling to Lck in thymocytes than CD8 coreceptor.[2] CD8.4 coreceptor has similar coupling to Lck as CD4 coreceptor, while the MHC I-binding site remains identical to wild-type CD8. This chimeric coreceptor therefore enables addressing influence of different coupling to Lck on TCR signaling.

References

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  1. ^ a b Erman, Batu; Alag, Amala S.; Dahle, Oyvind; van Laethem, François; Sarafova, Sophia D.; Guinter, Terry I.; Sharrow, Susan O.; Grinberg, Alexander; Love, Paul E. (2006-11-15). "Coreceptor signal strength regulates positive selection but does not determine CD4/CD8 lineage choice in a physiologic in vivo model". Journal of Immunology. 177 (10): 6613–6625. doi:10.4049/jimmunol.177.10.6613. ISSN 0022-1767. PMID 17082573.
  2. ^ Stepanek, Ondrej; Prabhakar, Arvind S.; Osswald, Celine; King, Carolyn G.; Bulek, Anna; Naeher, Dieter; Beaufils-Hugot, Marina; Abanto, Michael L.; Galati, Virginie (2014). "Coreceptor Scanning by the T Cell Receptor Provides a Mechanism for T Cell Tolerance". Cell. 159 (2): 333–345. doi:10.1016/j.cell.2014.08.042. PMC 4304671. PMID 25284152.