Cutting Edge: Role of MASP-3 in the Physiological Activation of Factor D of the Alternative Complement Pathway.
J Immunol
; 203(6): 1411-1416, 2019 09 15.
Article
em En
| MEDLINE
| ID: mdl-31399515
ABSTRACT
The complement system, a part of the innate immune system, can be activated via three different pathways. In the alternative pathway, a factor D (FD) plays essential roles in both the initiation and the amplification loop and circulates as an active form. Mannose-binding lectin-associated serine proteases (MASPs) are key enzymes of the lectin pathway, and MASP-1 and/or MASP-3 are reported to be involved in the activation of FD. In the current study, we generated mice monospecifically deficient for MASP-1 or MASP-3 and found that the sera of the MASP-1-deficient mice lacked lectin pathway activity, but those of the MASP-3-deficient mice lacked alternative pathway activity with a zymogen FD. Furthermore, the results indicate that MASP-3 but not MASP-1 activates the zymogen FD under physiological conditions and MASP-3 circulates predominantly as an active form. Therefore, our study illustrates that, in mice, MASP-3 orchestrates the overall complement reaction through the activation of FD.
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Base de dados:
MEDLINE
Assunto principal:
Proteínas do Sistema Complemento
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Fator D do Complemento
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Via Alternativa do Complemento
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Serina Proteases Associadas a Proteína de Ligação a Manose
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article