| First Author | Lin Q | Year | 1998 |
| Journal | J Immunol | Volume | 160 |
| Issue | 10 | Pages | 4681-7 |
| PubMed ID | 9590213 | Mgi Jnum | J:47424 |
| Mgi Id | MGI:1203427 | Doi | 10.4049/jimmunol.160.10.4681 |
| Citation | Lin Q, et al. (1998) T and B cell development in BP-1/6C3/aminopeptidase A-deficient mice. J Immunol 160(10):4681-7 |
| abstractText | Stage-restricted expression of cell surface molecules serves to delineate B lineage cells during their progressive differentiation within the bone marrow. The BP-1/6C3 Ag, aminopeptidase A (APA), is selectively expressed by the pre-B and immature B cells. This ectoenzyme, which is also present on bone marrow-derived stromal cells, thymic cortical epithelial cells, renal proximal tubular cells, intestinal enterocytes, and endothelial cells, cleaves acidic glutamyl and aspartyl residues from the N-terminus of angiotensin and other biologically active peptides to quench their functional activity. BP-1/6C3/APA expression by early B lineage cells is up-regulated by IL-7, an important growth factor for pre-B cells and T cells. To explore the physiologic role of this peptidase, we generated a mouse model of BP-1 deficiency by gene targeting in embryonal stem cells. While mice homozygous for the BP-1 mutation did not express detectable BP-1 protein or enzyme activity, they developed normally, generated normal numbers of T and B cells, exhibited integrity of Ab responses to both thymus-dependent and -independent Ags, and produced normal serum Ig levels. Phenotypic analysis of bone marrow and thymic lymphocytes indicated a normal pattern of B and T lineage differentiation. B lymphopoiesis in fetal liver cultures and the proliferative responses of bone marrow cells to IL-7 and LPS were also unimpaired. These findings indicate that BP-1 ectoenzyme activity is not essential for normal B and T cell development. |
