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Updated: Jun 13, 2026

Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
Regulation of thymocyte positive selection and motility by GIT2
Hyewon Phee1, Ivan Dzhagalov, Marianne Mollenauer
1Department of Medicine, University of California San Francisco, San Francisco, CA, USA.
None:
Thymocytes are highly motile cells that migrate under the influence of chemokines in distinct thymic compartments as they mature. The motility of thymocytes is tightly regulated; however, the molecular mechanisms that control thymocyte motility are not well understood. Here we report that G protein-coupled receptor kinase-interactor 2 (GIT2) was required for efficient positive selection. Notably, Git2(-/-) double-positive thymocytes showed greater activation of the small GTPase Rac, actin polymerization and migration toward the chemokines CXCL12 (SDF-1) and CCL25 in vitro. By two-photon laser-scanning microscopy, we found that the scanning activity of Git2(-/-) thymocytes was compromised in the thymic cortex, which suggests GIT2 has a key role in regulating the chemokine-mediated motility of double-positive thymocytes.
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