Mechanism of formation of human IgE-binding factors (soluble CD23): III. Evidence for a receptor (Fc epsilon RII)-associated proteolytic activity.
Mechanism of formation of human IgE-binding factors (soluble CD23): III. Evidence for a receptor (Fc epsilon RII)-associated proteolytic activity.
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DOI：
10.1084/jem.172.3.693
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发表时间：
1990-09-01
期刊：
影响因子：
--
通讯作者：
Delespesse G
中科院分区：
文献类型：
--
作者：
Letellier M;Nakajima T;Pulido-Cejudo G;Hofstetter H;Delespesse G
越来越多的证据表明Fc CD 23及其可溶性片段（IgE结合因子[BF]或可溶性CD 23）具有多效性活性。IgE-BF主要通过表面Fc ε RII的蛋白水解切割形成;它们首先作为37-和33-kD不稳定分子释放，随后转化为25-kD IgE-BF。在这项研究中，纯化和放射性碘标记的37-kD IgE-BFs以及45-kD Fc β RII被用作底物，以鉴定导致25-kD IgE-BFs形成的蛋白酶。当与几种携带Fc RII的细胞（包括CHO 1 -7细胞（用Fc RII cDNA转染））孵育时，这些底物产生25-kD IgE-BF;相比之下，Fc RII-细胞（包括CHO对照细胞）没有影响。高度纯化的未标记的天然37-kD和重组29-kD IgE-BF也将标记的45-kD Fc ε RII切割成25-kD IgE-BF。这些纯化的IgE-BF的蛋白水解活性通过与针对IgE-BF的抗体的免疫沉淀而被特异性地去除。这些数据有力地表明，Fc β RII和它的一些可溶性片段在产生IgE-BF的蛋白水解机制中起着积极的作用。由CHO 1 -7细胞释放的IgE-BF在与B细胞衍生的IgE-BF完全相同的位点被切割的观察结果支持了上述观点。总的来说，结果与自体蛋白水解过程相容。
There is mounting evidence that Fc epsilon RII (CD23) and its soluble fragments (IgE-binding factors [BFs] or soluble CD23) have pleiotropic activities. IgE-BFs are formed mainly by the proteolytic cleavage of surface Fc epsilon RII; they are first released as 37- and 33-kD unstable molecules that are subsequently transformed into 25-kD IgE- BFs. In this study, purified and radioiodinated 37-kD IgE-BFs as well as 45-kD Fc epsilon RII were used as substrates to identify the proteases leading to the formation of 25-kD IgE-BFs. These substrates generate 25-kD IgE-BFs when incubated with several Fc epsilon RII- bearing cells, including CHO1-7 cells (transfected with Fc epsilon RII cDNA); by contrast Fc epsilon RII- cells, including CHO control cells, have no effect. Highly purified unlabeled native 37-kD and recombinant 29-kD IgE-BFs also cleave labeled 45-kD Fc epsilon RII into 25-kD IgE- BFs. The proteolytic activity of these purified IgE-BFs is specifically removed by immunoprecipitation with an antibody against IgE-BFs. These data strongly suggest that Fc epsilon RII and some of its soluble fragments play an active role in the proteolytic mechanism generating IgE-BFs. They are supported by the observation that IgE-BFs released by CHO1-7 cells are cleaved exactly at the same sites as B cell-derived IgE-BFs. Taken collectively, the results are compatible with an autoproteolytic process.
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DOI：
10.1016/0167-5699(86)90184-2
发表时间：
1986-01-01
期刊：
IMMUNOLOGY TODAY
影响因子：
--
作者：
CAPRON, A;DESSAINT, JP;TONNEL, AB
通讯作者：
TONNEL, AB
DOI：
10.1073/pnas.82.24.8325
发表时间：
1985-12-01
影响因子：
11.1
作者：
DORSCHHASLER, K;KEIL, GM;KOSZINOWSKI, UH
通讯作者：
KOSZINOWSKI, UH
影响因子：
5.4
作者：
GORDON, J;CAIRNS, JA;GUY, GR
通讯作者：
GUY, GR
影响因子：
3.6
作者：
LETELLIER, M;SARFATI, M;DELESPESSE, G
通讯作者：
DELESPESSE, G
影响因子：
5.4
作者：
ARMITAGE, RJ;GOFF, LK
通讯作者：
GOFF, LK