| First Author | Iwaki D | Year | 2006 |
| Journal | J Immunol | Volume | 177 |
| Issue | 12 | Pages | 8626-32 |
| PubMed ID | 17142762 | Mgi Jnum | J:140667 |
| Mgi Id | MGI:3814282 | Doi | 10.4049/jimmunol.177.12.8626 |
| Citation | Iwaki D, et al. (2006) Small mannose-binding lectin-associated protein plays a regulatory role in the lectin complement pathway. J Immunol 177(12):8626-32 |
| abstractText | Mannose-binding lectin (MBL) and ficolins are pattern recognition proteins acting in innate immunity, and they trigger the activation of the lectin complement pathway through MBL-associated serine proteases (MASPs). Upon activation of the lectin pathway, MASP-2 cleaves C4 and C2. A truncated form of MASP-2, named small MBL-associated protein (sMAP), is also associated with MBL/ficolin-MASP complexes. To clarify the role of sMAP, we have generated sMAP-deficient (sMAP(-/-)) mice by targeted disruption of the sMAP-specific exon. Because of the gene disruption, the expression level of MASP-2 was also decreased in sMAP(-/-) mice. When recombinant sMAP (rsMAP) and recombinant MASP-2 (rMASP-2) reconstituted the MBL-MASP-sMAP complex in deficient serum, the binding of these recombinant proteins to MBL was competitive, and the C4 cleavage activity of the MBL-MASP-sMAP complex was restored by the addition of rMASP-2, whereas the addition of rsMAP attenuated the activity. Therefore, MASP-2 is essential for the activation of C4 and sMAP plays a regulatory role in the activation of the lectin pathway. |
