Huang C A, Henry C, Iacomini J, Imanishi-Kari T, Wortis H H
Department of Pathology, Tufts University School of Medicine, Boston, MA 02111, USA.
Eur J Immunol. 1996 Oct;26(10):2537-40. doi: 10.1002/eji.1830261039.
To determine directly whether B cell precursors of adult origin are capable of generating CD5+ B cells, we reconstituted neonatal C3H. SCID mice with adult C57BL/6 bone marrow and analyzed splenic B cells 10 months later. Surface staining and flow cytometry revealed that the B cells were of donor origin and that 30% were CD5+. This confirms that in vivo generated CD5+ B cells can be adult derived. After anti-IgM (but not lipopolysaccharide) stimulation in vitro, virtually all of the B cells from the bone marrow-reconstituted mice expressed surface CD5. Sequence analysis of expressed VHDJH genes from the CD5+ B cells present after anti-IgM stimulation revealed a high frequency of N nucleotide addition in CDR3 regions. The presence of N nucleotides indicates that these sequences were derived from CD5+ B cells of adult origin rather than from long-lived fetal precursor B cells present in either the adult bone marrow at the time of transfer or adult spleen. These experiments demonstrate conclusively that adult bone marrow contains precursors for CD5+ B cells and that unlike fetal liver-derived precursors these express terminal deoxynucleotidyl transferase.
为了直接确定成年来源的B细胞前体是否能够产生CD5+B细胞，我们用成年C57BL/6骨髓重建新生C3H.SCID小鼠，并在10个月后分析脾脏B细胞。表面染色和流式细胞术显示这些B细胞来自供体，且30%为CD5+。这证实了体内产生的CD5+B细胞可以是成年来源的。在体外抗IgM（而非脂多糖）刺激后，几乎所有来自骨髓重建小鼠的B细胞都表达表面CD5。对抗IgM刺激后出现的CD5+B细胞中表达的VHDJH基因进行序列分析，发现在互补决定区3（CDR3）区域N核苷酸添加频率很高。N核苷酸的存在表明这些序列源自成年来源的CD5+B细胞，而非来自转移时成年骨髓或成年脾脏中存在的长寿胎儿前体B细胞。这些实验确凿地证明成年骨髓含有CD5+B细胞的前体，并且与胎儿肝脏来源的前体不同，这些前体表达末端脱氧核苷酸转移酶。
