Hunter S, Kamoun M, Schreiber A D
Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104.
Proc Natl Acad Sci U S A. 1994 Oct 11;91(21):10232-6. doi: 10.1073/pnas.91.21.10232.
The human receptor Fc gamma RIIA for the Fc portion of IgG (Fc gamma) was expressed in a human T-cell line and conferred on these cells the ability to perform IgG antibody-stimulated phagocytosis. Crosslinking Fc gamma RIIA with anti-Fc gamma RII monoclonal antibody also induced tyrosine phosphorylation of multiple proteins including Fc gamma RIIA, ZAP-70, p72SYK, and phospholipase C gamma 1 subunit and an increase in intracellular Ca2+ concentration. The T cell receptor-associated zeta-chain was not tyrosine-phosphorylated after crosslinking of Fc gamma RIIA, suggesting that the Fc gamma RIIA-mediated signals were independent of CD3. Fc gamma RIIA-mediated signal transduction was defective in a transfected mutant T-cell line exhibiting reduced expression of the tyrosine kinases LCK and FYN. These studies indicate that certain T cells can assume phagocytic properties after transfection of cDNA encoding an Fc gamma receptor with the capability of inducing a phagocytic signal.
人IgG（Fcγ）Fc部分的受体FcγRIIA在人T细胞系中表达，并赋予这些细胞进行IgG抗体刺激的吞噬作用的能力。用抗FcγRII单克隆抗体交联FcγRIIA也会诱导多种蛋白质的酪氨酸磷酸化，包括FcγRIIA、ZAP-70、p72SYK和磷脂酶Cγ1亚基，并导致细胞内Ca2+浓度升高。FcγRIIA交联后，T细胞受体相关的ζ链未发生酪氨酸磷酸化，这表明FcγRIIA介导的信号独立于CD3。在转染的突变T细胞系中，FcγRIIA介导的信号转导存在缺陷，该细胞系中酪氨酸激酶LCK和FYN的表达降低。这些研究表明，某些T细胞在转染编码具有诱导吞噬信号能力的Fcγ受体的cDNA后，可以具有吞噬特性。
