Which one of the following statements about inhibitory receptors on natural killer (NK)cells is true?
A)Inhibitory receptors on NK cells express ITAM motifs in their cytoplasmic tails.
B)Some inhibitory receptors on NK cells recognize HLA-A or HLA-C.
C)Some inhibitory receptors on NK cells are members of the integrin family.
D)Some inhibitory receptors on NK cells are members of the Toll-like receptor family.
E)Inhibitory receptors on NK cells are not expressed on the same NK cells that express activating receptors.

Question

Quizplus · Accepted Answer

Natural killing (NK)inhibitory receptors recognize class I MHC molecules that are normally and constitutively expressed,including various alleles of HLA-A and HLA-C.The cytoplasmic tails of NK inhibitory receptors contain immunoreceptor tyrosine-based inhibitory motifs (ITIMs),but not immunoreceptor tyrosine-based activation motifs (ITAMs).Some inhibitory receptors on NK cells are members of the Ig superfamily,but not the integrin or TLR families.NK cells usually express both activating and inhibitory receptors,and activation is regulated by a balance between signals generated from both types of receptors.The inhibitory receptors on NK cells bind to self class I MHC molecules,which are expressed on most normal cells.When activating and inhibitory receptors are simultaneously engaged,the inhibitory receptor signals dominate and the NK cell is not activated.

Which One of the Following Statements About Inhibitory Receptors on Natural