부산대학교 도서관

Activated NK cells in appropriate conditions are known to express stem cell antigen 1 (Sca-1/Ly-6A/E). To investigate its production, NK cells isolated from mouse spleens were incubated ex vivo in the presence of different combinations of cytokines (IL-12, IL-15, IL-18, and IFN[gamma]). Expression of Sca-1 was found to be considerably higher in NK cells incubated in the presence of IL-18, IL-15, and IL-12 than in those treated with IL-15 and IL-18 only. To test the hypothesis that the effect of IL-12 was due to stimulation of IFN[gamma] production, we replaced IL-12 with IFN[gamma] in some samples and added specific anti-IFN[gamma] antibody to some samples cultured with IL-15/IL-18+IL-12. In the subpopulations incubated in the presence of IL-15/IL-18 with added IFN[gamma] instead of IL-12, the expression of Sca-1 was not increased. By contrast, in samples treated with IL-15/IL-18+IL-12 and anti-IFN[gamma] antibody, the expression of Sca-1 was activated to a similar extent as in those stimulated by IL-15/IL-18+IL-12 combination without the antibody. The obtained data suggest that IL-12 activates the production of Sca-1 by NK cells through an IFN[gamma]-independent mechanism. Key Words: murine spleen; freshly isolated cultured NK-cells; cytokines; Sca-1/Ly-6A/E stem cell antigen 1; cellular progenitors
Natural killer (NK) cells are effector lymphocytes of the innate immunity, which are able to directly recognize virus-infected, neoplastic, and/or stressed cells, and to perform constitutive cytolysis. These lymphocytes play [...]