FLOW CYTOMETRY IN IMMUNOLOGY AND HEMATOLOGY 

Minerva Biotecnologica 1999 June;11(2):129-37

Copyright © 1999 EDIZIONI MINERVA MEDICA

language: English

Natural killer cell function in flow cytometry

Zamai L. ¹, Mariani A. ², Papa S. ¹, Reno F. ¹, Vitale M. ³

¹ Institute of Morphological Sciences, Scientific Campus, University of Urbino; ² Institute of Human Anatomy, University of Bologna; ³ Department of Biomedical and Biotechnological Sciences, Human Anatomy Section, University of Brescia, Italy

Background. Natural Killer ­cells are an impor­tant ­line of ­defense ­against new­ly aris­ing malig­nant ­cells and ­cells infect­ed ­with virus­es, bac­te­ria, and pro­to­zoa. They ­have the abil­ity to medi­ate a spon­ta­ne­ous cyto­tox­ic­ity ­against a varie­ty of ­cell ­types includ­ing nor­mal allog­e­ne­ic ­cells, viral­ly infect­ed ­cells, and ­tumor ­cells. NK ­cell activ­ity is fine­ly ­tuned by the oppos­ing activ­ity of stim­u­la­to­ry and inhib­i­to­ry recep­tors, ­with spec­i­fic­ity for var­i­ous MHC-I allo­types. Lysis of the tar­get can be ­achieved by dif­fer­ent mech­a­nisms, includ­ing cyto­tox­ic gran­ule exo­cy­to­sis and pro­duc­tion of sol­u­ble fac­tors. We stud­ied the pos­sibil­ity ­offered by ­flow cytom­e­try to ­give a com­pre­hen­sive quan­ti­tative eval­u­a­tion of ­human NK ­cell activ­ity.
Method. Human NK ­cells, rec­og­nised by spe­cif­ic mono­clo­nal anti­bod­ies, and ­tumor tar­gets ­were ana­lysed by ­flow cytom­e­try ­after the bind­ing and kill­ing phas­es of ­their activ­ity.
Results. The two phas­es of NK lyt­ic activ­ity (bind­ing and kill­ing) can be meas­ured by ­flow cytom­e­try, in a sin­gle ­test ­tube. The ­flow cytom­e­try meth­o­dol­o­gies ­described ­here ­give the quan­ti­ta­tive meas­ure­ment of NK ­cell bind­ing to ­tumor tar­gets and of ­their lyt­ic activ­ity.
Conclusions. The meas­ure­ment of NK ­cell func­tion ­should be per­formed in spe­cif­ic instanc­es, ­such as on ­patients expe­ri­enc­ing or sus­pect­ed of auto­im­mune dis­or­ders, chron­ic ­fatigue ­immune dys­func­tion syn­drome (­CFIDS), repeat­ed infec­tions, chem­o­ther­a­py, treat­ment ­with bio­log­i­cal mod­i­fi­ers ­such as IL-2. Flow cytom­e­try can meas­ure ­both bind­ing and kill­ing NK ­cell func­tions, and is ­fast, inde­pen­dent of the oper­a­tor, sta­tis­ti­cal­ly reli­able, ­avoids the use of radio­ac­tive mate­ri­al and per­forms the anal­y­sis at sin­gle ­cell lev­el rath­er ­than on ­whole PBL.