biostudies-literatureKao HNIAID NIH HHS8248-57https://www.ebi.ac.uk/biostudies/studies/S-EPMC2857686biostudies-literatureUnknown181(12)The mechanism underlying the transient accumulation of CD4 at the immunological synapse (IS) and its significance for T cell activation are not understood. To investigate these issues, we mutated a serine phosphorylation site (S408) in the cytoplasmic tail of murine CD4. Preventing phosphorylation of S408 did not block CD4 recruitment to the IS; rather, it blocked the ability of CD4 to leave the IS. Surprisingly, enhanced and prolonged CD4 accumulation at the supramolecular activation cluster in the contact area had no functional consequence for T cell activation, cytokine production, or proliferation. Protein kinase C theta (PKCtheta)-deficient T cells also displayed enhanced and prolonged accumulation of wild-type CD4 at the IS, indicating that theta is the critical PKC isoform involved Journal of immunology (Baltimore, Md. : 1950)Regulated movement of CD4 in and out of the immunological synapse.PMC2857686P01 AI071195AI071195R37 AI024157R37 AI024157-21P01 AI071195-03AI24157R01 AI024157Littman DRAllen PMLin JShaw ASKao HfalseRegulated movement of CD4 in and out of the immunological synapse.The mechanism underlying the transient accumulation of CD4 at the immunological synapse (IS) and its significance for T cell activation are not understood. To investigate these issues, we mutated a serine phosphorylation site (S408) in the cytoplasmic tail of murine CD4. Preventing phosphorylation of S408 did not block CD4 recruitment to the IS; rather, it blocked the ability of CD4 to leave the IS. Surprisingly, enhanced and prolonged CD4 accumulation at the supramolecular activation cluster in the contact area had no functional consequence for T cell activation, cytokine production, or proliferation. Protein kinase C theta (PKCtheta)-deficient T cells also displayed enhanced and prolonged accumulation of wild-type CD4 at the IS, indicating that theta is the critical PKC isoform involved 2008-01-01T00:00:00Z2008 Dec2025-04-04T13:38:35.201Z2019-03-26T23:42:52ZS-EPMC28576861905024110.4049/jimmunol.181.12.8248