THE HUMAN MONOCYTE-LIKE CELL-LINE THP-1 EXPRESSES FC-GAMMA-RI AND FC-GAMMA-RII
THE HUMAN MONOCYTE-LIKE CELL-LINE THP-1 EXPRESSES FC-GAMMA-RI AND FC-GAMMA-RII
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DOI：
10.1002/jlb.49.6.556
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发表时间：
1991-06-01
影响因子：
5.5
通讯作者：
KOBASIUK, CD
中科院分区：
文献类型：
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作者：
FLEIT, HB;KOBASIUK, CD
THP-1细胞是一种来源于急性单核细胞白血病患者的单核细胞样细胞系，与其他白血病细胞系不同，它具有正常的二倍体核型。我们通过流式细胞术、放射性标记的IgG1和单抗结合试验以及生化分析鉴定了Fc-Gamma-R在该细胞系上的表达。用抗Fc-Gamma-RI、II和III单抗和兔抗Fc-Gamma-RIIIF(ab‘)2对THP-1细胞进行的流式细胞术分析表明，这些细胞只表达Fc-Gamma-RI和Fc-Gamma-RII。一组抗Fc-γ-RIII单抗(抗CD16)不能与THP-1细胞结合。生化研究确定了的多肽为78 kDa(Fc-Gamma-RI)和42-53 kDa(Fc-Gamma-RII)。通过与放射性碘标记的人IgG1(检测Fc-Gamma-RI)、mAbIV.3(检测Fc-Gamma-RII)或兔免疫复合物的结合来检测Fc-Gamma-R的表达。在THP-1细胞上发现了3.5万个高亲和力结合位点(解离常数[K(D)]=4.22x10(-9m))。干扰素-γ可上调THP-1细胞Fc-γ-RI的表达，是THP-1细胞的2.8倍，而对U937细胞的Fc-Gamma-RI则增加6~8倍。佛波酯、肿瘤坏死因子-α和维生素D3对THP-1细胞与IgG1的结合无影响。免疫复合体中的5万个免疫球蛋白分子与THP-1细胞结合。干扰素-γ处理使这种结合增加了4倍，PMA处理使结合的免疫复合体的数量增加了50%，而维生素D3处理的THP-1细胞结合的免疫复合体是对照细胞的一半。利用单抗IV.3的结合分析确定每个细胞有50,000个结合位点。THP-1细胞经干扰素-γ、肿瘤坏死因子-α、PMA或维生素D3处理后，Fc-γ-RII的表达无明显变化。抑制研究表明，Fc-γ-RI在免疫复合物结合中起主导作用。人IgG1mAb和小鼠抗Fc-Gamma-RII单抗对免疫复合物结合的抑制作用为76%~84%，而小鼠抗Fc-Gamma-RII的IgG1mAb对免疫复合物结合的抑制作用最小。Fc-γ-R的表达可能与THP-1细胞的分化无关，因为只有1，25维生素D3能够诱导成熟单核细胞表型的标志CD14的表达。
THP-1 cells are a monocyte-like cell line derived from a patient with acute monocytic leukemia and unlike other leukemic cell lines has a normal diploid karyotype. We have characterized Fc-gamma-R expression on this cell line by flow cytometry, radiolabeled IgG1 and monoclonal antibody (mAb) binding assays, and biochemical analysis. Flow cytometric analysis of THP-1 cells with anti-Fc-gamma-RI, II, and III mAb, and a rabbit anti-Fc-gamma-RIII F(ab')2 demonstrated that only Fc-gamma-RI and Fc-gamma-RII are expressed by these cells. A panel of anti-Fc-gamma-RIII mAb (anti-CD16) failed to bind to THP-1 cells. Biochemical studies identified polypeptides of 64 to 78 kDa (Fc-gamma-RI) and of 42 to 53 kDa (Fc-gamma-RII). Fc-gamma-R expression was determined by binding of radioiodinated human IgG1 (to detect Fc-gamma-RI), mAb IV.3 (to detect Fc-gamma-RII), or rabbit IgG immune complexes. Thirty-five thousand high affinity binding sites (dissociation constant [K(D)] = 4.22 x 10(-9M) for IgG1 were found on THP-1 cells. Interferon-gamma (IFN-gamma) upregulated Fc-gamma-RI expression by THP-1 cells 2.8-fold, whereas Fc-gamma-RI on U937 cells was increased six- to eight-fold by this cytokine. Phorbol myristate acetate (PMA), tumor necrosis factor-alpha (TNF-alpha), and vitamin D3 had no effect on IgG1 binding by THP-1 cells. Fifty thousand IgG molecules in immune complexes bound to THP-1 cells. IFN-gamma treatment increased this binding by four-fold, PMA treatment resulted in a 50% increase in the number of IgG immune complexes bound, whereas vitamin D3 treated THP-1 cells bound half as many IgG immune complexes as control cells. Binding assays utilizing mAb IV.3 identified 50,000 sites per cell. Treatment of THP-1 cells with IFN-gamma, TNF-alpha, PMA, or vitamin D3 had no effect on Fc-gamma-RII expression. That Fc-gamma-RI plays a predominant role in immune complex binding was demonstrated by inhibition studies. Human IgG1 as well as mouse IgG2a mAb to Fc-gamma-RII inhibited immune complex binding by 76 to 84%, whereas mouse IgG1 mAb to Fc-gamma-RII had minimal effect on immune complex binding. Fc-gamma-R expression may not be linked to differentiation of THP-1 cells since only 1,25 vitamin D3 was able to induce the expression of CD14, a marker of mature monocytic phenotype.