Moţa G, Moraru I, Nicolae M, Moraru I
Department of Immunology, Victor Babeş Institute, Bucharest, Romania.
Mol Immunol. 1988 Feb;25(2):95-101. doi: 10.1016/0161-5890(88)90056-9.
The interaction between the Fc receptor for IgA (FcR alpha) and human secretory IgA (sIgA) was studied in a heterologous system by using rabbit alveolar macrophages or splenic lymphocytes. The capacity of FcR alpha-bearing cells to interact with the ligand via the Fc region was demonstrated. The proportion of FcR alpha-bearing lymphocytes and macrophages was found to be 11 and 17%, respectively. The cell-bound radiolabelled ligand showed a release half-time of 70 min for lymphocytes and 45 min for macrophages. The equilibrium constant (K) and the maximum number of ligand molecules bound per cell (n) in mean values was 5.2 +/- 0.05 X 10(8) M-1 and 3.3 +/- 0.15 X 10(5) molecules per cell, respectively. Increased percentages of FcR alpha-bearing cells and of ligand density per cell were obtained after stimulation by lung inflammation. A significant increase of the K value was recorded with macrophages from rabbits with lung acute inflammation (mean value 7.3 +/- 0.21 + 10(8) M-1) while the increase with lymphocytes was not significant. The calculation method of K and n is discussed.
利用兔肺泡巨噬细胞或脾淋巴细胞，在异源系统中研究了IgA的Fc受体（FcRα）与人分泌型IgA（sIgA）之间的相互作用。证实了携带FcRα的细胞通过Fc区域与配体相互作用的能力。发现携带FcRα的淋巴细胞和巨噬细胞的比例分别为11%和17%。细胞结合的放射性标记配体对淋巴细胞的释放半衰期为70分钟，对巨噬细胞为45分钟。平衡常数（K）和每个细胞结合的配体分子的最大数量（n）的平均值分别为5.2±0.05×10⁸ M⁻¹和每个细胞3.3±0.15×10⁵个分子。肺部炎症刺激后，携带FcRα的细胞百分比和每个细胞的配体密度增加。患有肺部急性炎症的兔的巨噬细胞的K值显著增加（平均值7.3±0.21×10⁸ M⁻¹），而淋巴细胞的增加不显著。讨论了K和n的计算方法。
