Dynamic molecular interactions linking the T cell antigen receptor to the actin cytoskeleton

Barda-Saad M, Braiman A, Titerence R, Bunnell SC, Barr VA and Samelson LE
Source: Nat Immunol
Publication Date: (2005)
Issue: 6(1): 80-89
Research Area:
Immunotherapy / Hematology
Cells used in publication:
T cell, human stim.
Species: human
Tissue Origin: blood
PBMC, human
Species: human
Tissue Origin: blood
Nucleofector® I/II/2b
Cells of the human Jurkat cell lines E6.1, JCaM2.5, and J14 were transfected by nucleofection with DNA constructs coding for several proteins fused to fluorescent proteins and/or tags. Transiently transfected T cell cultures and stable clones were used. Stable clones were derived from transiently transfected cells with a combination of drug selection and cell sorting by FACS. In some cases two constructs were also cotransfected into Jurkat cells. In addition, stimulated primary human T lymphocytes were transfected with several of the above constructs.
T cell receptor (TCR) engagement leads to actin polymerization at the site of T cell contact with antigen-presenting cells. Here we have studied the dynamic activity of proteins involved in regulating actin polymerization in live T cells after activation. Two such adaptor proteins, Nck and the Wiskott-Aldrich syndrome protein (WASp), were recruited to the TCR during initial T cell activation, where they colocalized with the tyrosine kinase Zap70. The recruitment of Nck and WASp depended on TCR-induced tyrosine phosphorylation and the LAT and SLP-76 adaptors. Nck and WASp migrated peripherally and accumulated at an actin-rich circumferential ring. Thus, actin polymerization regulated by the TCR begins at the TCR. Molecules recruited to the TCR regulate actin polymerization and this process drives plasma membrane movement and cellular spreading.