The same tyrosine-based inhibition motif, in the intra-cytoplasmic domain of FcγRIIB, regulates negatively BCR-, TCR-, and FcR-dependent cell activation

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• 作者：Marc Daë ; ron ; Sylvain Latour ; Odile Malbec ; Eric Espinosa ; Patrick Pina ; Suzanne Pasmans ; Wolf H. Fridman
• 刊名：Immunity
• 出版年：1995
• 出版时间：November 1995
• 年：1995
• 卷：3
• 期：5
• 页码：635-646
• 全文大小：1355 K

文摘

The cell-triggering properties of BCR, TCR and FcR depend on structurally related immunoreceptor tyrosine-based activation motifs (ITAMs). FcγR1113 have no ITAM and do not trigger cell activation. When coaggregated to BCR, they inhibit B cell activation. We show here that, when coaggregated to these receptors, FcγRIIB inhibit FcεRI-, FcγRIIA-, and TCR-dependent cell activation. Inhibition also affected cell activation by single ITAMs, in isolated FcR or TCR subunits. The same tyrosine-based inhibitory motif (ITIM), which is highly conserved in murine and human FcγR11B and that was previously shown to inhibit BCR-dependent B cell activation, was required to regulate TCR- and FcR-dependent cell activation. Our findings endow FcγRIIB, and thus IgG antibodies, with general immunoregulatory properties susceptible to act on all ITAM-containing receptors.