title: Lck is required for stromal cell-derived factor 1 alpha (CXCL12)-induced lymphoid cell chemotaxis.
abstract: Stromal cell-derived factor 1alpha (CXCL12) induces chemotaxis of lymphocytes through its receptor CXCR4. We examined the role of nonreceptor tyrosine kinases in CXCL12-induced chemotaxis of T cells and natural killer (NK) cells. Damnacanthal, a specific Lck inhibitor, but not the Syk inhibitor piceatannol, inhibited CXCL12-induced chemotaxis of both lymphocyte subsets. Similarly, damnacanthal was shown to inhibit CXCL12-induced chemotaxis of the Jurkat T-cell line. Stimulating T and NK cells with CXCL12 increased both the tyrosine phosphorylation and the kinase activity of Lck. A direct involvement of Lck in CXCL12-induced chemotaxis was demonstrated in the Lck-deficient Jurkat-derived cell line JCaM1.6. Although JCaM1.6 cells express CXCR4, no significant migration was detected after CXCL12 stimulation. Reconstitution with wild-type Lck restored both CXCL12-induced chemotaxis and Lck activation. Furthermore, cotransfection of wild-type Lck with C-terminal Src kinase (Csk) into JCaM1.6 failed to restore the chemotactic response induced by CXCL12. Finally, by targeting critical residues in the Src homology-2 (SH2) or SH3 domains of Lck, we observed that the SH3 domain is important for the function of Lck in CXCL12-mediated chemotaxis. Together, these results suggest a role for Lck in CXCL12-induced signaling pathways leading to lymphocyte chemotaxis.
authors.affiliation: Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, Norway. marit.inngjerdingen@basalmed.uio.no
authors.forename: Marit
authors.initials: M
authors.lastname: Inngjerdingen
authors.forename: Knut Martin
authors.initials: KM
authors.lastname: Torgersen
authors.forename: Azzam A
authors.initials: AA
authors.lastname: Maghazachi
mesh_terms: D000880:Anthraquinones / Q000494:pharmacology; D002460:Cell Line; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000494:pharmacology* / Q000502:physiology; D002634:Chemotaxis, Leukocyte / Q000187:drug effects*; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000187:drug effects; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000037:antagonists & inhibitors / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects; D018909:src Homology Domains / Q000502:physiology; D019061:src-Family Kinases / Q000502:physiology
chemical_list: D000880:Anthraquinones; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; C079170:damnacanthal; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D019061:src-Family Kinases