Inhibitory Fc receptors modulate in vivo cytotoxicity against tumor targets.
Nat Med
; 6(4): 443-6, 2000 Apr.
Article
en En
| MEDLINE
| ID: mdl-10742152
ABSTRACT
Inhibitory receptors have been proposed to modulate the in vivo cytotoxic response against tumor targets for both spontaneous and antibody-dependent pathways. Using a variety of syngenic and xenograft models, we demonstrate here that the inhibitory FcgammaRIIB molecule is a potent regulator of antibody-dependent cell-mediated cytotoxicity in vivo, modulating the activity of FcgammaRIII on effector cells. Although many mechanisms have been proposed to account for the anti-tumor activities of therapeutic antibodies, including extended half-life, blockade of signaling pathways, activation of apoptosis and effector-cell-mediated cytotoxicity, we show here that engagement of Fcgamma receptors on effector cells is a dominant component of the in vivo activity of antibodies against tumors. Mouse monoclonal antibodies, as well as the humanized, clinically effective therapeutic agents trastuzumab (Herceptin(R)) and rituximab (Rituxan(R)), engaged both activation (FcgammaRIII) and inhibitory (FcgammaRIIB) antibody receptors on myeloid cells, thus modulating their cytotoxic potential. Mice deficient in FcgammaRIIB showed much more antibody-dependent cell-mediated cytotoxicity; in contrast, mice deficient in activating Fc receptors as well as antibodies engineered to disrupt Fc binding to those receptors were unable to arrest tumor growth in vivo. These results demonstrate that Fc-receptor-dependent mechanisms contribute substantially to the action of cytotoxic antibodies against tumors and indicate that an optimal antibody against tumors would bind preferentially to activation Fc receptors and minimally to the inhibitory partner FcgammaRIIB.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Melanoma Experimental
/
Antígenos CD
/
Linfoma de Células B
/
Receptores de IgG
/
Receptor ErbB-2
/
Citotoxicidad Celular Dependiente de Anticuerpos
Límite:
Animals
/
Female
/
Humans
/
Male
Idioma:
En
Revista:
Nat Med
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MEDICINA
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos