Human decidual NK cells form immature activating synapses and are not cytotoxic.
In early pregnancy invading fetal trophoblasts encounter abundant maternal decidual natural killer cells (dNK). dNK express perforin, granzymes A and B and the activating receptors NKp30, NKp44, NKp46, NKG2D, and 2B4 as well as LFA-1. Even though they are granular and express the essential molecules required for lysis, fresh dNK displayed very reduced lytic activity on classical MHC I negative targets K562 and 721.221, approximately 15% of that of peripheral NK cells. dNK formed conjugates and activating immune synapses with 721.221 and K562 cells in which CD2, LFA-1 and actin were polarized toward the contact site. However, in contrast to peripheral NK cells, they failed to polarize their microtubule organizing centers and perforin-containing granules to the synapse, accounting for their lack of cytotoxicity.
Kopcow
Hernan D
HD
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA. hkopcow@fas.harvard.edu
Allan
David S J
DS
Chen
Xi
X
Rybalov
Basya
B
Andzelm
Milena M
MM
Ge
Baoxue
B
Strominger
Jack L
JL
D002450:Cell Communication; D016764:Cell Polarity; D003594:Cytoplasmic Granules / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D003656:Decidua / Q000276:immunology*; D005260:Female; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology* / Q000648:ultrastructure; D008213:Lymphocyte Activation; D008562:Membrane Glycoproteins / Q000502:physiology; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D011247:Pregnancy
D015395:Histocompatibility Antigens Class I; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D054353:Perforin