Slauson S D, Silva H T, Sherwood S W, Morris R E
Transplantation Immunology, Department of Cardiothoracic Surgery, Stanford University School of Medicine, CA 94305-5247, USA.
Immunol Lett. 1999 Apr 15;67(3):179-83. doi: 10.1016/s0165-2478(99)00007-3.
Malononitrilamides (MNAs) are a new class of immunomodulatory drug highly effective in in vivo models of allo- and xenotransplantation. Knowledge of their effects on immune cells, however, is limited and has been derived solely from investigations using isolated mononuclear cells. This use of purified cells to investigate drug activity is not ideal, so we have combined the analytical power of flow cytometry with our mitogen-driven, whole blood lymphocyte activation and proliferation assays to investigate the in vitro mechanism of action of MNAs. We first show that MNAs (A77 1726, HMR1279, and HMR1715), as well as brequinar (BQR) and cyclosporine (CsA), effectively inhibit cell activation antigen expression and lymphocyte proliferation. We next show that the inhibitory effects of MNAs and BQR, but not CsA, are reversed by the addition of uridine to the culture. These results suggest that inhibition of pyrimidine biosynthesis may be a mechanism by which MNAs suppress both lymphocyte activation and proliferation since these effects were reversed when uridine nucleotide pools were replenished. This novel finding of suppression of activation antigen expression by MNAs in whole blood expands our understanding of the effects of this new class of drug.
丙二腈酰胺（MNAs）是一类新型免疫调节药物，在同种异体和异种移植的体内模型中具有高效性。然而，关于它们对免疫细胞作用的了解有限，且仅来自于使用分离的单核细胞进行的研究。使用纯化细胞来研究药物活性并不理想，因此我们将流式细胞术的分析能力与有丝分裂原驱动的全血淋巴细胞活化和增殖试验相结合，以研究MNAs的体外作用机制。我们首先表明，MNAs（A77 1726、HMR1279和HMR1715）以及布喹那（BQR）和环孢素（CsA）能有效抑制细胞活化抗原表达和淋巴细胞增殖。接下来我们表明，在培养物中添加尿苷可逆转MNAs和BQR的抑制作用，但不能逆转CsA的抑制作用。这些结果表明，抑制嘧啶生物合成可能是MNAs抑制淋巴细胞活化和增殖的一种机制，因为当尿苷核苷酸池得到补充时，这些作用会被逆转。MNAs在全血中抑制活化抗原表达这一新颖发现扩展了我们对这类新型药物作用的理解。
