Yonago Acta medica 1998;41:715
Effect of a Nitric Oxide Donor on Intracellular Cytokine Production in Normal Human Peripheral Lymphocytes
Akira Yamasaki, Katsuyuki Tomita and Yutaka Hitsuda
Third Department of Internal Medicine, Faculty of Medicine, Tottori University, Yonago 683-0826 Japan
It has been recently suggested that nitric oxide (NO) plays an important role
in modulating immune responses including helper T (Th) cell differentiation. To investigate
the effect of NO on cytokine production in T cells, we examined in vitro the percentage
of interferon (IFN)-γ and interleukin (IL)-4 producing cells by the intracellular
cytokine staining method with flow cytometry. The percentage of IFN-γ and IL-4
producing cells reached maximal value 8 h after stimulation by phorbol 12-myristate
13-acetate (PMA) and ionomycin. When an NO donor, sodium nitroprusside (SNP), was
co-incubated with PMA and ionomycin for 8 h, nitrite levels increased in a dose dependent
manner for SNP (P=0.007; Friedman test). The percentage of IFN-γ producing
cells was diminished in consequence of the increasing doses of SNP (P=0.002;
Friedman test). While the percentage of IL-4 producing cells tended to be diminished
by SNP, this difference, however, was statistically not significant (P=0.062;
Friedman test). Therefore, we have suggested that NO might affect Th cell differentiation
through inhibition of Th1-cytokine production and might cause a Th2 cell predominant
state.
Key words: IFN-γ; IL-4; intracellular cytokines; NO; sodium nitroprusside