IgM-mediated opsonization and cytotoxicity in the shark.
J Leukoc Biol
; 61(2): 141-6, 1997 Feb.
Article
em En
| MEDLINE
| ID: mdl-9021918
ABSTRACT
Two types of cytotoxic reactions have been observed using cells from the nurse shark spontaneous cytotoxicity mediated by cells of the macrophage lineage and antibody-dependent killing carried out by a different effector cell population. Previous data showed that removal of phagocytic cells using iron particles abolished macrophage-mediated killing, but not antibody-dependent reactions. The current study used single cell assays and showed that the effector of antibody-driven reactions was the neutrophil. Surprisingly, the mechanism of killing was shown to be phagocytosis mediated by both 7S and 19S immunoglobulin M (IgM). Reactions proceeded with as little as 0.01 microg of purified 19S or 7S IgM and were complete within 4-6 h. In contrast, purified immunoglobulin did not adsorb to macrophages and had no effect on target cell binding or cytotoxicity. Pretreatment of cells with cytochalasin D abolished the phagocytic reaction, but not spontaneous cytotoxicity. These data show that antibody-mediated killing results from opsonization and phagocytosis; the mechanism of macrophage killing is currently unknown. In addition, these data show that the shark neutrophil, not the macrophage lineage, carries a receptor for Fc mu.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tubarões
/
Imunoglobulina M
/
Proteínas Opsonizantes
/
Citotoxicidade Celular Dependente de Anticorpos
Limite:
Animals
Idioma:
En
Revista:
J Leukoc Biol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos