Sasaki A, Levison S W, Ting J P
Lineberger Cancer Center, University of North Carolina, Chapel Hill 27599.
J Neuroimmunol. 1990 Sep-Oct;29(1-3):213-22. doi: 10.1016/0165-5728(90)90164-i.
The roles of intracellular second messengers in interferon-gamma (IFN-gamma)-induced Ia antigen (Ag) expression by astroglia and microglia were examined. Ia Ag on both glia types was induced by IFN-gamma. Reagents known to increase intracellular cAMP or activate intracellular protein kinase C (PKC) reduced IFN-gamma-induced Ia Ag expression by astroglia. In contrast, increasing intracellular cAMP had no suppressive effect on Ia Ag expression by microglia. These results indicate (1) cAMP and PKC negatively regulate IFN-gamma-induced Ia expression on astroglia, and (2) Ia expression is regulated differentially in astroglia vs. microglia. These findings may explain the frequent observation of Ia+ microglia (or macrophages) but not astroglia in various neurodegenerative diseases.
研究了细胞内第二信使在γ干扰素（IFN-γ）诱导星形胶质细胞和小胶质细胞Ia抗原（Ag）表达中的作用。两种胶质细胞类型上的Ia Ag均由IFN-γ诱导。已知能增加细胞内cAMP或激活细胞内蛋白激酶C（PKC）的试剂可降低IFN-γ诱导的星形胶质细胞Ia Ag表达。相反，增加细胞内cAMP对小胶质细胞的Ia Ag表达没有抑制作用。这些结果表明：（1）cAMP和PKC对IFN-γ诱导的星形胶质细胞Ia表达起负调节作用；（2）星形胶质细胞和小胶质细胞中Ia表达的调节存在差异。这些发现可能解释了在各种神经退行性疾病中经常观察到Ia +小胶质细胞（或巨噬细胞）而非星形胶质细胞的现象。
