Kumar R K, Lykke A W, Penny R
J Natl Cancer Inst. 1981 Dec;67(6):1277-82.
The properties of a factor responsible for immunosuppressive activity in the plasma of inbred SJL/J mice bearing transplanted lymphomas were investigated. Suppressive activity was not due to an intact virus but resided in a soluble molecule characterized as a nonimmunoglobulin protein of molecular weight 68,000-88,000. The plasma suppressor factor was relatively stable and was neither directly cytotoxic nor complement-dependent. The degree of suppression of in vitro lymphocyte proliferative responses depended on the time of addition of plasma to cultures. Suppression was reversible if cells exposed to plasma were washed before mitogen stimulation, but stimulated cells exposed to the suppressor factor were irreversibly inhibited. The suppressor factor was partially species-specific. Supernatants from short-term cultures of tumor cells from lymph nodes of SJL/L mice contained a similar suppressor factor, indicating that the plasma factor was probably a product of tumor cells.
对携带移植性淋巴瘤的近交系SJL/J小鼠血浆中一种具有免疫抑制活性的因子的特性进行了研究。抑制活性并非源于完整病毒，而是存在于一种可溶性分子中，该分子被鉴定为分子量为68,000 - 88,000的非免疫球蛋白蛋白质。血浆抑制因子相对稳定，既无直接细胞毒性，也不依赖补体。体外淋巴细胞增殖反应的抑制程度取决于将血浆加入培养物的时间。如果在有丝分裂原刺激前将暴露于血浆的细胞洗涤，则抑制作用是可逆的，但暴露于抑制因子的受刺激细胞则被不可逆地抑制。抑制因子具有部分种属特异性。来自SJL/L小鼠淋巴结肿瘤细胞短期培养物的上清液中含有类似的抑制因子，这表明血浆因子可能是肿瘤细胞的产物。
