Fridman W H, Mathiot C, Montcuit J, Teillaud J L
Laboratoire d'Immunologie Cellulaire et Clinique, INSERM Unité 255, Paris, France.
Nouv Rev Fr Hematol (1978). 1988;30(5-6):311-5.
FcRs for all isotypes of Ig are found on lymphocytes and on lymphocyte derived tumour cells. Due to the availability of monoclonal antibodies, FcR for IgE (Fc epsilon R) and for IgG (Fc gamma R) have been characterized and their genes have been cloned. These receptors are markers of leucocyte sub-populations. Fc epsilon RII(CD23) in almost exclusively expressed on B lymphocytes and B tumour cells. Fc gamma RII(CDw32) is found on B lymphocytes, but also on monocytes, neutrophils, eosinophils and platelets. Fc gamma RIII(CD16) is mostly borne by granulocytes, but is also a marker of NK cells ans some T lymphocytes. FcR are molecules which are readily released in the sera where they can be detected by radioimmunoassays and dot-blot assays. The amount of circulating Fc epsilon RII is strongly increased in sera from patients with B-CLL and this increase seems to be related to the Rai stage of the disease. Circulating Fc gamma RIII is not grossly modified in B-CLL, although some patients have very low amounts of these molecules. The significance of these data has to be envisioned in view of the possible role of immunoglobulin-Binding Factors (IBF), FcR-related immunoregulatory lymphokines, in the control of B cell proliferation. For instance, IgE-BF, a cleavage product of Fc epsilon RII has been proposed to act as an autocrine growth factor on malignant B cells. IgG-BF, antigenically related to Fc gamma RII in the mouse and to Fc gamma RIII in the human, inhibits the IgG production and the growth of malignant B cells. Thus, the dosage of FcRs and IBFs could bring new insights in the monitoring of B cell proliferations, including B-CLL.
免疫球蛋白所有同种型的Fc受体存在于淋巴细胞和淋巴细胞衍生的肿瘤细胞上。由于单克隆抗体的可得性，免疫球蛋白E（FcεR）和免疫球蛋白G（FcγR）的Fc受体已得到鉴定，其基因也已被克隆。这些受体是白细胞亚群的标志物。FcεRII（CD23）几乎只在B淋巴细胞和B肿瘤细胞上表达。FcγRII（CDw32）存在于B淋巴细胞上，但也存在于单核细胞、中性粒细胞、嗜酸性粒细胞和血小板上。FcγRIII（CD16）主要由粒细胞携带，但也是自然杀伤细胞和一些T淋巴细胞的标志物。Fc受体是易于释放入血清中的分子，在血清中可通过放射免疫测定法和斑点印迹测定法进行检测。B细胞慢性淋巴细胞白血病患者血清中循环FcεRII的量显著增加，这种增加似乎与疾病的Rai分期有关。在B细胞慢性淋巴细胞白血病中，循环FcγRIII没有明显改变，尽管一些患者这些分子的量非常低。鉴于免疫球蛋白结合因子（IBF）、与Fc受体相关的免疫调节性淋巴因子在控制B细胞增殖中的可能作用，必须设想这些数据的意义。例如，有人提出FcεRII的裂解产物IgE-BF可作为恶性B细胞的自分泌生长因子。在小鼠中与FcγRII抗原相关、在人类中与FcγRIII抗原相关的IgG-BF可抑制IgG的产生和恶性B细胞的生长。因此，Fc受体和IBF的定量分析可能会为包括B细胞慢性淋巴细胞白血病在内的B细胞增殖监测带来新的见解。
