Antibodies against growth factor receptors can inhibit the proliferation of transformed cells via a cis-interaction with inhibitory FcR.
Immunol Lett
; 143(1): 28-33, 2012 Mar 30.
Article
em En
| MEDLINE
| ID: mdl-22553780
ABSTRACT
When dimerized by Stem Cell Factor (SCF), the Receptor Tyrosine Kinase Kit triggers the proliferation of hematopoietic progenitors, including pro-B cells, and of some differentiated cells, including mast cells. We found previously that anti-Kit antibodies can mimic SCF and that anti-Kit-induced mast cell proliferation can be inhibited by the low-affinity IgG receptors FcγRIIB, when the two receptors are co-aggregated by IgG immune complexes. We show here that the same immune complexes inhibited anti-Kit-induced proliferation of Ba/F3 pro-B cells expressing wt Kit and FcγRIIB and that inhibition required the intracytoplasmic domain of FcγRIIB. Constitutively active Kit mutants are oncogenic. We show that Kit-dependent, ligand-independent proliferation of Ba/F3 cells expressing a constitutively dimerized Kit mutant was also inhibited by IgG immune complexes via FcγRIIB. FcγRIIB-dependent negative regulation therefore also affects Kit-dependent proliferation of transformed cells. Interestingly, the co-aggregation of Kit with FcγRIIB by immune complexes containing SCF also inhibited both growth factor-dependent and growth factor-independent proliferation of Ba/F3 cells expressing wt or mutated Kit, respectively. These results provide the basis for novel immunotherapeutical approaches of FcγRIIB-expressing tumors.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores Fc
/
Receptores de Fatores de Crescimento
/
Proliferação de Células
/
Anticorpos
Limite:
Animals
Idioma:
En
Revista:
Immunol Lett
Ano de publicação:
2012
Tipo de documento:
Article