| First Author | Law CL | Year | 1995 |
| Journal | J Immunol | Volume | 155 |
| Issue | 7 | Pages | 3368-76 |
| PubMed ID | 7561031 | Mgi Jnum | J:28782 |
| Mgi Id | MGI:76321 | Doi | 10.4049/jimmunol.155.7.3368 |
| Citation | Law CL, et al. (1995) Ig domains 1 and 2 of murine CD22 constitute the ligand-binding domain and bind multiple sialylated ligands expressed on B and T cells. J Immunol 155(7):3368-76 |
| abstractText | Baby hamster kidney cells transfected with murine CD22 (mCD22) mediate adhesion to B- and T-lineage cells. To further characterize mCD22-mediated cell adhesion, we generated a panel of recombinant globulins (Rg) consisting of different extracellular Ig-like (Ig) domains of mCD22. FACS analysis using these mCD22.Rgs revealed that ligands for mCD22 are expressed on both B and T cell lines and also normal B and T cells. In B-lineage cells, the expression of mCD22 ligands began on sIgM- pre-B cells in bone marrow. The ligand-binding site of mCD22 for ligands was mapped to Ig domains 1 and 2: mCD22.Rgs containing Ig domains 1 and 2 bound target cells and immunoprecipitated sets of glycoproteins similar to Rgs containing Ig domains 1 to 3 or all 7 CD22 Ig domains, whereas Rgs containing Ig domains 2 to 3 or 3 to 7 did not bind either B or T cells. Furthermore, B cells apparently expressed higher levels of mCD22 ligands than that of T cells, suggesting a potential competition for CD22 binding between ligands expressed on the same B cell and those expressed on another B cell or T cells. Immunoprecipitation experiments using the mCD22.Rgs identified mCD22 itself and the B cell-specific isoform of mCD45RA (B220) as two of the mCD22 ligands expressed on B cells. Thus, mCD22 may potentially regulate B cell activation through interactions with itself or mCD45RA/B220. |
