Analysis of heat shock protein 70 as a causal molecule of aplastic anemia

为探讨再生障碍性贫血（AA）的免疫病理生理学特征，我们采用流式细胞术研究了未经治疗的AA患者外周血单个核细胞（PBMCs）中热休克蛋白（-hsp）72的表达。热处理后PBMC中hsp 72+细胞百分比较高（>30%）的AA患者可能对环孢素治疗有反应。在其他血液病如骨髓增生异常综合征和溶血性贫血中未检测到hsp 72的高诱导表达。在对环孢素有反应的AA患者的PBMC中，主要在T细胞中检测到hsp 72表达。因此，在治疗前检测PBMC中的hsp 72 ^+细胞似乎有助于预测对环孢素治疗的良好反应。接下来，我们收集了AA患者的PBMC，这些患者后来接受了来自日本其他医院的由抗胸腺细胞球蛋白和环孢素组成的联合免疫抑制治疗，并确定了hsp 72的诱导。虽然约40%的 关于我们 Hsp 72在AA患者PBMC中的阳性率较高，但联合免疫抑制治疗的疗效与Hsp 72的高表达无关，部分AA患者不仅在PBMC胞浆中表达Hsp 72，而且在红细胞表面也表达Hsp 72。对红细胞表面hsp 72的详细分析表明，除AA患者外，在约30%的正常人的20-90%的红细胞上可检测到hsp 72 ^+细胞，其表达仅限于A型和AB型个体。热处理不影响红细胞表面hsp 72的表达。由于hsp 72不能在由具有A型血的正常个体的红系祖细胞产生的正常红细胞成红细胞上检测到，hsp 72似乎在红系祖细胞终末分化后出现在RBC上。除hsp 72外，A型和AB型个体的RBC表达hsp 90。在O型红细胞中未观察到抗hsp 72单克隆抗体的结合，所述O型红细胞通过用N-乙酰氨基半乳糖转移酶和UDP-N-乙酰氨基半乳糖处理而被迫表达A抗原。因此，hsp 72的表达似乎是由遗传决定的，尽管它与A抗原表达密切相关。hsp 72在红细胞上的功能和生物学意义仍有待确定。少

To characterize immune pathophysiology of aplastic anemia (AA), we studied expression of heat shock piotein (-hsp) 72 in peripheral blood mononuclear cells (PBMCs) of untreated AA patients using flow cytometry. AA patients whose PBMCs exhibited high percentages (>30%) of hsp72+ cells after heat treatment were likely to respond to cyclosporine therapy. The high inducibility of hsp72 in PBMCs was not detected in other hematologic diseases, such as myelodysplastic syndrome and hemolytic anemia. Among PBMCs of AA patients responsive to cyclosporine, hsp72 expression was primarily detected in T cells. Thus, detection of hsp72^+ cell in PBMCs before treatments appeared to be useful for predicting a favorable response to cyclosporine therapy. Next, we collected PBMCs of AA patients who later received combined immunosuppressive therapy consisting of antithymocyte globulin and cyclosporine from the other hospitals in Japan, and determined the inducibility of hsp72. Although approximately 40% of … More patients showed high percentages of hsp72^+ cell among PBMCs, there was no correlation between a good response to the combined immunosuppressive therapy and a high inducibility of hsp72 in PBMCs.In some AA patients, hsp72 was detectable not only in the cytoplasm of PBMCs but also on the surface of red blood cells (RB Cs). Detailed analysis of hsp72 on RBCs revealed that in additi9n to AA patients, hsp72^+ cells could be detected on 20-90% of RBCs of about 30% of normal individuals and that its expression was restricted to individuals bearing blood type A and AB.Heat treatments did not influence the expression of hsp72 on RB Cs. Since hsp72 could not be detected on normocytic erythroblasts that were generated from erythroid progenitor cells of a normal individual with blood type A, hsp72 appeared to emerge on RBCs after terminal differentiation of erythroid progenitor cells. Beside hsp72, RBCs of individuals with blood type A and AB expressed hsp90. Binding of anti-hsp72 monoclonal antibodies was not seen in type O RBCs that were forced to express A antigens by the treatment with N-acetyl galactosaminyltransferase and UDP-N-acefyl galactosamine. Thus, the expression of hsp72 seemed to be genetically determined although it is closely associated with A antigen expression. The function and biological significance of hsp72 on RBCs remain to be determined. Less