Mansikka A, Veromaa T, Vainio O, Toivanen P
Department of Medical Microbiology, Turku University, Finland.
Scand J Immunol. 1989 Mar;29(3):325-31. doi: 10.1111/j.1365-3083.1989.tb01131.x.
We have studied the expression of immunoglobulin genes in the chicken B-cell precursors, and of a B-cell surface marker (Bu-1) on the bursal and peripheral B cells during normal ontogeny. Since there is no way of distinguishing the precursor cells from the more mature bursal lymphocytes on the basis of surface markers, we chose to study the total bursal lymphocyte population at ages when the numbers of the various precursor cells (bursal, early post-bursal, and post-bursal stem cells) in the bursa are estimated to be at their highest. Thereafter, comparisons with the more mature lymphocytes in the peripheral organs were made. As a result, levels of the lambda and mu transcripts and expression of Bu-1 antigen in the chicken B-cell precursors were found to be unchanged during the post-hatching period. In the light of these experiments, the later events of B-cell differentiation, i.e. the development from the bursal to post-bursal B lymphocytes, occurs without the lambda, mu, and Bu-1 gene loci involved. On the other hand, the higher level of lambda and mu expression in the splenic B lymphocytes indicates that the post-bursal stem cells mature into highly active plasma cells after seeding to the peripheral organs.
我们研究了鸡B细胞前体中免疫球蛋白基因的表达，以及正常个体发育过程中法氏囊和外周B细胞上B细胞表面标志物（Bu-1）的表达。由于无法根据表面标志物区分前体细胞和更成熟的法氏囊淋巴细胞，我们选择在法氏囊中各种前体细胞（法氏囊、法氏囊后早期和法氏囊后干细胞）数量估计最高的年龄阶段，研究法氏囊淋巴细胞的总体群体。此后，与外周器官中更成熟的淋巴细胞进行了比较。结果发现，鸡B细胞前体中λ和μ转录本的水平以及Bu-1抗原的表达在孵化后阶段没有变化。根据这些实验，B细胞分化的后期事件，即从法氏囊B淋巴细胞向法氏囊后B淋巴细胞的发育，在没有λ、μ和Bu-1基因座参与的情况下发生。另一方面，脾B淋巴细胞中λ和μ表达的较高水平表明，法氏囊后干细胞在播种到外周器官后成熟为高活性浆细胞。
