The role of CXCR4 in regulating the directional migration of T lymphocyte

  • 蔡 怡瑩

Student thesis: Master's Thesis

Abstract

Aberrant lymphocytes accumulation due to disregulation of T cell migration is a major cause of chronic inflammation T lymphocyte migration is a highly coordinated process that is regulated by chemokines and its receptors Identifying the mechanism of T lymphocyte migration may contribute to clarify the etiology of many inflammation- related disorders Chemokine receptor CXCR4 and its ligand stromal cell-derived factor 1 (SDF-1) regulate cell migration and adhesion ZAP70 protein is a tyrosine kinase activated by CXCR4/SDF-1 signaling Our previous studies showed that ZAP70 protein accumulated unevenly in migrating cells in a chemoattractant SDF-1 gradient A part of them is localized close to the protruding membrane of lamellipodia along with direction of migration and the others are localized at the trailing edge In this study we found that ZAP70 bound to CXCR4 after SDF-1 stimulation ZAP70 protein was co-localized with CXCR4 by CXCR4 antibody-induced patching of Jurkat and primary T cells Therefore we hypothesized that CXCR4 plays a role in the recruitment of ZAP70 protein at lemallipodia To investigate the interaction between CXCR4 and ZAP70 we have constructed hCXCR4-hDsRed fusion protein to study the dynamic localization of ZAP70 and CXCR4 during T lymphocyte migration The expression of pDsRed-hCXCR4 in both Jurkat and P116 T cells was confirmed by RT-PCR Overexpression of CXCR4 increased the transmigration towards SDF-1 and induced ZAP70 ERK phosphorylation and ?1-integrin activation suggesting that the hCXCR4-DsRed protein is functional We then co-expressed both hCXCR4-DsRed and hZAP70-EGFP fusion proteins in T cells and found that the distribution of hCXCR4-DsRed overlapped with hZAP70-EGFP during cell migration By using cell^R time-lapse imaging system we observed that hCXCR4-DsRed first located at the cell membrane then recruited hZAP70-EGFP and protruding lamellipodium was formed In conclusion CXCR4 plays a role in regulating the formation of lemellipodia and controlling the directionality of T cell migration through interaction with ZAP70
Date of Award2014 Aug 16
Original languageEnglish
SupervisorBei-Chang Yang (Supervisor)

Cite this

The role of CXCR4 in regulating the directional migration of T lymphocyte
怡瑩, 蔡. (Author). 2014 Aug 16

Student thesis: Master's Thesis