ISSN:
1365-3083
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
We have studied whether engagement of MHC class I (MHC—I) molecules on natural killer (NK) cells can influence the NK killing activity. Human NK effector cells, enriched by nylon wool passage, were incubated with monoclonal antibodies (MoAb) to MHC—I followed by cross-linking with secondary rabbit anti mouse Ig or streptavidin. Cross linking of MHC—I molecules on NK cells resulted in a clear inhibition of the NK activity against the target cells K562, Molt-4 and U937. The inhibitory effect was selective for MHC—I and was not seen with MoAb to MHC—II or CD56 molecules. The inhibition was not mediated via Fc receptors since F(ab)2 fragments of the MHC—I MoAb W6/32 were as effective as the intact antibody. The best inhibition of NK activity was obtained using biotin-labelled F(ab)2 fragments of W6/32 and streptavidin as a cross-linker, where up to 70 % reduction in NK cell activity was observed. Antibody dependent cellular cytotoxicity (ADCC) was also inhibited by cross-linking MHC—I molecules on the effector cells.The results show that antibody mediated cross-linking of MHC—I proteins on NK cells can inhibit their killing capacity. This indicates that MHC—I molecules on NK cells can be involved in the regulation of NK cytotoxicity, perhaps by transmitting inhibitory signals into the NK cell.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1365-3083.1995.tb03622.x
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