Howard M C, Fidler J M
Aust J Exp Biol Med Sci. 1977 Oct;55(5):501-7.
While the virgin AFC-progenitors for an adoptive immune response in neonatal germ-free CBA mouse spleen are small, dense cells, the equivalent cells in the adult are a larger, lighter density population. The effects of injections of unrelated antigens on the physical properties of the AFC-progenitors in neonatal spleen were investigated to test the postulate that the physically distinct "virgin" AFC-progenitors in the adult arose by a process of non-specific activation. Spleen cells from 7-day-old germ-free CBA mice were separated by sedimentation at unit gravity or by density on continuous albumin gradients, and the fractions were tested for NIP-specific AFC-progenitor activity using an adoptive immune assay which gave a direct linear measure of B cell activity. If the donor neonatal animals were injected one day previously with POL or PPD, the NIP-specific AFC-progenitor activity shifted from the typical small, dense lymphocytes to larger, lighter cells. The physical properties of these stimulated AFC-progenitors resembled those of IgM AFC-progenitors in normal adult mice. These results experimentally confirm the theory that environmental stimuli induce a non-specific "activation" of a particular subset of "virgin" B cells.
虽然新生无菌CBA小鼠脾脏中用于过继免疫反应的初始AFC祖细胞是小而致密的细胞，但成年小鼠中相应的细胞群体更大、密度更低。研究了注射无关抗原对新生脾脏中AFC祖细胞物理特性的影响，以检验成年小鼠中物理性质不同的“初始”AFC祖细胞是通过非特异性激活过程产生的这一假设。通过单位重力沉降或在连续白蛋白梯度上进行密度分离，从7日龄无菌CBA小鼠的脾脏细胞中分离出不同组分，并使用过继免疫测定法检测各组分的NIP特异性AFC祖细胞活性，该测定法可直接线性测量B细胞活性。如果供体新生动物在一天前注射了POL或PPD，NIP特异性AFC祖细胞活性就会从典型的小而致密的淋巴细胞转变为更大、更轻的细胞。这些受刺激的AFC祖细胞的物理特性类似于正常成年小鼠中的IgM AFC祖细胞。这些结果通过实验证实了环境刺激会诱导特定亚群的“初始”B细胞发生非特异性 “激活” 这一理论。
