Production of Stem Cell Antigen 1 Sca-1/Ly-6A/E by Freshly Isolated NK Cells Cultured with Relevant Cytokines.

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 IFNγ). 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 IFNγ production, we replaced IL-12 with IFNγ in some samples and added specific anti-IFNγ 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 IFNγ 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-IFNγ 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 IFNγ-independent mechanism.

[Serum IgG antibodies to GD1a and GM1 gangliosides in elderly people].

Nowadays, the percentage of elderly people in society grows. Good nutrition and medical care help older people to have a normal life over 80 to 90 years. In the last ten years it is of critical importance to establish the clinical significance of serum IgG anti-GD1a and anti-GM1 ganglioside antibodies as potential biomarkers for neuronal damage in neurodegenerative diseases and immune-mediated neuropathies and demyelination. In the current study, the diagnostic values of IgG anti-GD1a and anti-GM1 antibodies were determined by the ELISA method in serum samples of 18 elderly patients (71-91 years). Significantly elevated serum IgG anti-GD1a and anti-GM1 antibodies titers were detected only in patients over 80 years. These data suggest that the immune-mediated neuropathies, neurodegeneration and demyelination in healthy elderly occur after 80 years old. Therefore, IgG anti-GD1a and anti-GM1 antibodies can serve as biomarkers, showing the nervous system dysfunction.