Spatial organization of signal transduction molecules in the NK cell immune synapses during MHC class I-regulated noncytolytic and cytolytic interactions.
The cytolytic activity of NK cells is tightly regulated by inhibitory receptors specific for MHC class I Ags. We have investigated the composition of signal transduction molecules in the supramolecular activation clusters in the MHC class I-regulated cytolytic and noncytolytic NK cell immune synapses. KIR2DL3-positive NK clones that are specifically inhibited in their cytotoxicity by HLA-Cw*0304 and polyclonal human NK cells were used for conjugate formation with target cells that are either protected or are susceptible to NK cell-mediated cytotoxicity. Polarization of talin, microtubule-organizing center, and lysosomes occurred only during cytolytic interactions. The NK immune synapses were analyzed by three-dimensional immunofluorescence microscopy, which showed two distinctly different synaptic organizations in NK cells during cytolytic and noncytolytic interactions. The center of a cytolytic synapse with MHC class I-deficient target is comprised of a complex of signaling molecules including Src homology (SH)2-containing protein tyrosine phosphatase-1 (SHP-1). Closely related molecules with overlapping functions, such as the Syk kinases, SYK, and ZAP-70, and adaptor molecules, SH2 domain-containing leukocyte protein of 76 kDa and B cell linker protein, are expressed in activated NK cells and are all recruited to the center of the cytolytic synapse. In contrast, the noncytolytic synapse contains SHP-1, but is lacking other components of the central supramolecular activation cluster. These findings indicate a functional role for SHP-1 in both the cytolytic and noncytolytic interactions. We also demonstrate, in three-cell conjugates, that a single NK cell forms a cytolytic synapse with a susceptible target cell in the presence of both susceptible and nonsusceptible target cells.
Vyas
Y M
YM
Immunology Program, Sloan-Kettering Institute for Cancer Research, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
Mehta
K M
KM
Morgan
M
M
Maniar
H
H
Butros
L
L
Jung
S
S
Burkhardt
J K
JK
Dupont
B
B
D016764:Cell Polarity; D003599:Cytoskeleton / Q000378:metabolism; D003602:Cytotoxicity, Immunologic; D004792:Enzyme Precursors / Q000302:isolation & purification; D015236:HLA-C Antigens / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007365:Intercellular Junctions; D047908:Intracellular Signaling Peptides and Proteins; D007694:Killer Cells, Natural / Q000276:immunology*; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000302:isolation & purification; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification; D011971:Receptors, Immunologic / Q000378:metabolism; D054340:Receptors, KIR; D054344:Receptors, KIR2DL3; D015398:Signal Transduction; D000072377:Syk Kinase; D051746:ZAP-70 Protein-Tyrosine Kinase; D018909:src Homology Domains
D004792:Enzyme Precursors; D015236:HLA-C Antigens; D015395:Histocompatibility Antigens Class I; D047908:Intracellular Signaling Peptides and Proteins; C515078:KIR2DL3 protein, human; D011971:Receptors, Immunologic; D054340:Receptors, KIR; D054344:Receptors, KIR2DL3; D011505:Protein-Tyrosine Kinases; C000606896:SYK protein, human; D000072377:Syk Kinase; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases