Humphrey J H, Grennan D
Eur J Immunol. 1981 Mar;11(3):221-8. doi: 10.1002/eji.1830110311.
Fluorescent conjugates of hydroxyethyl (OEt) starch of Ficoll are selectively ingested and retained in vivo by spleen marginal-zone (MZ) and lymph node marginal-sinus macrophages of mice, whereas similar conjugates of type 3 pneumococcal capsular polysaccharide (SIII) are generally retained by macrophages (Kupffer cells, histiocytes, macrophages of spleen, lymph nodes, bone marrow and peritoneal cavity). MZ and other macrophages are readily identifiable by fluorescence after injection in vivo of OEt starch and SIII labeled with tetraethylrhodamine isothiocyanate and fluorescein isothiocyanate. Collagenase digestion was required for recovery of intact MZ macrophages from spleen in single cell suspensions and for maximum yields of other macrophages. MZ macrophages are larger and morphologically distinct from other macrophages, but resemble them in respect of EA, EAC receptors and acid phosphates and nonspecific esterase content and are equally radio-resistant. The appear normal in CBA/N nude and in beige mice. Freshly isolated MZ macrophages in suspension have adherent lymphocytes, dispersible by EDTA treatment, with B but not T cell markers. It is suggested that selective adherence to MZ macrophages is a factor in determining B cell traffic. MZ macrophages did not have demonstrable surface I-A or I-EC antigens. Only 4--8% of other spleen macrophages freshly isolated by collagenase treatment expressed I-A in the same preparation, whereas 35% of other cells (lymphocytes and blasts) reacted with monoclonal anti-I-A and anti-I-EC. After adherence to glass or plastic, 40% or more red-pulp, but not MZ macrophages, became I-A-positive. When taken from mice recently restimulated with sheep erythrocytes, half the red-pulp macrophages expressed I-A even before adherence. The relation of MZ to other macrophages is not known. However, their properties are consistent with the demonstrated ability of thymus-independent antigens selectively taken up by these cells to elicit long-lasting IgM antibody responses by direct interaction with B cells. The unexpected observation that only a small proportion of spleen macrophages freshly isolated from unstimulated mice had detectable surface I-A, but that this proportion was much increased after attachment to plastic, is discussed in relation to the possibility that macrophages do not express surface Ia antigens unless they have been stimulated.
羟乙基（OEt）淀粉与菲可（Ficoll）的荧光共轭物可被小鼠脾脏边缘区（MZ）和淋巴结边缘窦巨噬细胞选择性摄取并保留在体内，而3型肺炎球菌荚膜多糖（SIII）的类似共轭物通常被巨噬细胞（枯否细胞、组织细胞、脾脏、淋巴结、骨髓和腹腔巨噬细胞）保留。在体内注射用异硫氰酸四乙罗丹明和异硫氰酸荧光素标记的OEt淀粉和SIII后，通过荧光可轻易识别MZ和其他巨噬细胞。为了从脾脏的单细胞悬液中回收完整的MZ巨噬细胞以及获得其他巨噬细胞的最大产量，需要进行胶原酶消化。MZ巨噬细胞比其他巨噬细胞更大，形态上也有所不同，但在EA（红细胞抗体）、EAC（致敏红细胞抗体补体复合物）受体以及酸性磷酸酶和非特异性酯酶含量方面与它们相似，并且同样具有放射抗性。它们在CBA/N裸鼠和米色小鼠中看起来正常。悬浮状态下新鲜分离的MZ巨噬细胞有黏附的淋巴细胞，经EDTA处理可分散，这些淋巴细胞具有B细胞而非T细胞标记。有人提出，对MZ巨噬细胞的选择性黏附是决定B细胞迁移的一个因素。MZ巨噬细胞没有可检测到的表面I-A或I-Ec抗原。通过胶原酶处理新鲜分离的其他脾脏巨噬细胞中，只有4% - 8%在同一制剂中表达I-A，而其他细胞（淋巴细胞和成纤维细胞）中有35%与单克隆抗I-A和抗I-Ec发生反应。黏附到玻璃或塑料上后，40%或更多的红髓巨噬细胞（而非MZ巨噬细胞）变为I-A阳性。从最近用绵羊红细胞再次刺激的小鼠中获取的红髓巨噬细胞，甚至在黏附之前就有一半表达I-A。MZ与其他巨噬细胞的关系尚不清楚。然而，它们的特性与已证实的非胸腺依赖性抗原被这些细胞选择性摄取后通过与B细胞直接相互作用引发持久IgM抗体反应的能力是一致的。文中讨论了一个意外的观察结果，即从未经刺激的小鼠新鲜分离的脾脏巨噬细胞中只有一小部分有可检测到的表面I-A，但在黏附到塑料上后这一比例大幅增加，这一现象与巨噬细胞除非受到刺激否则不表达表面Ia抗原的可能性有关。
