Pivotal advance: characterization of mouse liver phagocytic B cells in innate immunity.
J Leukoc Biol
; 91(4): 537-46, 2012 Apr.
Article
em En
| MEDLINE
| ID: mdl-22058423
ABSTRACT
Although B cells in vertebrates have been thought to lack phagocytic activity, there has been a recent report of such ability by the B cells of early vertebrates such as fish and frogs. Here, we show for the first time that mouse liver IgM(+) B cells actively phagocytose microsphere beads and Escherichia coli and that they effectively kill bacterial cells. Such phagocytic activity is not observed in other liver MNCs, except for F4/80(+) Kupffer cells. In the presence of fresh mouse serum (but not heat-inactivated serum), the heat-killed E. coli phagocytic activity of liver B cells increased significantly but was inhibited significantly by anticomplement component C3 antibody, suggesting E. coli opsonization by serum factors, including complement components. Upon i.v. injection of FITC-labeled E. coli into mice, a substantial proportion of liver B cells phagocytosed the bacteria, as compared with spleen B cells. Functional phagolysosome formation in liver B cells was supported by several reagents showing an acidic change and lysosomes in the phagocytosed vacuoles. Indeed, mouse liver B cells killed viable E. coli more efficiently than did spleen B cells in vitro. Further, E. coli-phagocytic liver B cells produced a substantial amount of IL-12. These results indicate that liver B cells have phagocytic and bactericidal activities similar to those of dedicated phagocytes and may contribute to bacterial clearance.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fagocitose
/
Proteínas do Sistema Complemento
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Linfócitos B
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Interleucina-12
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Imunidade Inata
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Fígado
Limite:
Animals
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Japão