Learning how to discriminate between friends and enemies, a lesson from Natural Killer cells.
Human Natural Killer cells express a large array of surface receptors that are involved in the regulation of the different NK cell functions. Some of these receptors, by sensing the expression of HLA class I on potential target cells, deliver negative signals that inhibit the NK-mediated killing. In the absence of such inhibitory interactions, other receptors are allowed to transduce activating signals that result in NK-mediated attack of tumor- or virus-transformed cells. The function of these main activating receptors is supported and enhanced by the simultaneous engagement of different co-receptors. Finally, the ability of NK cells to interact with normal, non-transformed other cells such as dendritic cells (DC) appears to crucially contribute to the regulation of both innate and adaptive immune responses.
Bottino
Cristina
C
Istituto Giannina Gaslini, L.go. G. Gaslini 5, Genova 16148, Italy.
Moretta
Lorenzo
L
Pende
Daniela
D
Vitale
Massimo
M
Moretta
Alessandro
A
D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000276:immunology / Q000502:physiology*; D011971:Receptors, Immunologic / Q000276:immunology / Q000502:physiology*; D015398:Signal Transduction / Q000276:immunology / Q000502:physiology*
D015395:Histocompatibility Antigens Class I; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic