Dodge W H, Love S H, Bryant D L, Mitchell R H
Exp Hematol. 1980 Apr;8(4):395-403.
Serum obtained from young chicks stimulated with endotoxin contained elevated levels of colony-stimulating activity (CSA). This CSA was partially characterized. Incubation at 65 degrees C (60 min) had no effect on the ability of the CSA to support colony formation by nonadherent cells but reduced 3-4 fold its ability to support colony formation by unfractionated marrow cells. These data suggest that most of the serum activity is due to a heat-labile, adherent cell-dependent factor which does not directly affect the nonadherent granulocyte/monocyte colony-forming cell (GM-CFC). The ability of serum to support colony formation was increased by chloroform extraction. This was evidently due to the presence of inhibitory lipoproteins. The lipoprotein fraction of pigeon serum was found to directly block colony formation. The CSA for nonadherent cells migrated as one peak in the postalbumin region during zone electrophoresis. When electrofocused, heterogeneity was detected but all activity was associated with molecules with isoelectric points between pH 4 and 5. Following sequential fractionation by chloroform extraction, ultrafiltration, zone electrophoresis, isoelectric focusing and gel filtration (Ultrogel AcA 44), the activity was separated from most of the remaining protein. One peak of activity was obtained at the excluded volume.
从用内毒素刺激的幼雏获得的血清中，集落刺激活性（CSA）水平升高。对这种CSA进行了部分特性分析。在65℃（60分钟）孵育对CSA支持非贴壁细胞形成集落的能力没有影响，但使其支持未分级骨髓细胞形成集落的能力降低了3 - 4倍。这些数据表明，大部分血清活性归因于一种热不稳定的、依赖贴壁细胞的因子，该因子不直接影响非贴壁粒细胞/单核细胞集落形成细胞（GM - CFC）。血清支持集落形成的能力通过氯仿萃取而增加。这显然是由于存在抑制性脂蛋白。发现鸽血清的脂蛋白部分直接阻断集落形成。非贴壁细胞的CSA在区带电泳过程中在后白蛋白区域以一个峰的形式迁移。当进行等电聚焦时，检测到了异质性，但所有活性都与等电点在pH 4至5之间的分子相关。通过氯仿萃取序贯分级分离、超滤、区带电泳、等电聚焦和凝胶过滤（Ultrogel AcA 44）后，活性与大部分剩余蛋白质分离。在排阻体积处获得了一个活性峰。
