Mendelsohn J, Nordberg J
J Clin Invest. 1979 Jun;63(6):1124-32. doi: 10.1172/JCI109405.
Lymphocytes were purified from peripheral blood of normal donors and patients with chronic lymphocytic leukemia (CLL) by Ficoll-Hypaque centrifugation. Adenylate cyclase activity, expressed as picomoles [(32)P]cyclic AMP generated per milligram protein per minute, was 57+/-4 in normals and 26+/-4 in CLL patients. Enzyme activity, expressed as picomoles [(32)P]cyclic AMP generated per 10(6) lymphocytes per minute, was 2.09+/-0.19 for normal lymphocytes and 1.10+/-0.16 for CLL lymphocytes. The differences between normal and CLL peripheral lymphocytes are highly significant (P < 0.001) with either method of calculating activity. Cyclic AMP levels (picomoles per 10(6) lymphocytes) also differed significantly: 1.38+/-0.29 for normals and 0.45+/-0.08 for CLL lymphocytes. Adenylate cyclase was assayed in lymphocytes enriched for bone marrow-derived (B) cells by removing E-rosetted thymus-derived (T) cells, and enriched for T cells by harvesting E-rosetted lymphocytes or by removing B cells with nylon wool absorption. Solutions to simultaneous equations gave the following calculated enzyme activities for pure B- and T-cell subpopulations (in picomoles [(32)P]cyclic AMP generated per milligram mg protein per minute): normal B, 196+/-22; normal T, 30+/-10; CLL B, 34+/-6; CLL T, 19+/-4. Thus. normal B-lymphocyte adenylate cyclase exceeds normal T-lymphocyte activity by more than sixfold, whereas in the case of CLL the enzyme activity in B lymphocytes is markedly reduced to levels comparable to T lymphocytes. The responses of lymphocytes to stimulation with the hormones prostaglandin E(1) and isoproterenol, and with NaF, were assessed. Compared with normal lymphocytes, enzyme activities were reduced in CLL lymphocytes incubated with these agents, but to a degree paralleling the reduced basal activities. Thus, the ratios between stimulated and basal adenylate cyclase levels in Ficoll-Hypaque-purified, normal lymphocytes were 2.3+/-0.1 after incubation with 10 muM isoproterenol, and 3.9+/-0.2 with 10 mM NaF, values which did not differ significantly from those obtained with CLL lymphocytes. When the enzyme activities calculated for purified T- and B-lymphocyte subpopulations were used to derive the stimulation ratios, the responses of normal and CLL T and B cells to these agents were also indistinguishable. The simplest explanation for these findings is a reduced number of normally responsive enzyme sites on the surface membranes of CLL lymphocytes, although alternative explanations are possible.
通过Ficoll-Hypaque离心法从正常供体和慢性淋巴细胞白血病（CLL）患者的外周血中纯化淋巴细胞。腺苷酸环化酶活性以每分钟每毫克蛋白质产生的皮摩尔数[（32）P]环磷酸腺苷表示，正常人为57±4，CLL患者为26±4。以每分钟每10^6个淋巴细胞产生的皮摩尔数[（32）P]环磷酸腺苷表示的酶活性，正常淋巴细胞为2.09±0.19，CLL淋巴细胞为1.10±0.16。用两种计算活性的方法计算，正常和CLL外周淋巴细胞之间的差异均非常显著（P<0.001）。环磷酸腺苷水平（每10^6个淋巴细胞的皮摩尔数）也有显著差异：正常人为1.38±0.29，CLL淋巴细胞为0.45±0.08。通过去除E花环形成的胸腺来源（T）细胞，对富含骨髓来源（B）细胞的淋巴细胞进行腺苷酸环化酶检测；通过收集E花环形成的淋巴细胞或用尼龙毛吸附去除B细胞，对富含T细胞的淋巴细胞进行检测。联立方程的解给出了纯B细胞和T细胞亚群的以下计算酶活性（以每分钟每毫克蛋白质产生的皮摩尔数[（32）P]环磷酸腺苷表示）：正常B细胞，196±22；正常T细胞，30±10；CLL B细胞，34±6；CLL T细胞，19±4。因此，正常B淋巴细胞的腺苷酸环化酶活性比正常T淋巴细胞活性高六倍以上，而在CLL中，B淋巴细胞中的酶活性明显降低至与T淋巴细胞相当的水平。评估了淋巴细胞对激素前列腺素E1、异丙肾上腺素和NaF刺激的反应。与正常淋巴细胞相比，用这些试剂孵育的CLL淋巴细胞中的酶活性降低，但降低程度与基础活性降低程度平行。因此，在与10μM异丙肾上腺素孵育后，Ficoll-Hypaque纯化的正常淋巴细胞中刺激后的腺苷酸环化酶水平与基础水平之比为2.3±0.1，与10mM NaF孵育时为3.9±0.2，这些值与CLL淋巴细胞获得的值无显著差异。当用纯化的T细胞和B细胞亚群计算的酶活性来推导刺激比时，正常和CLL的T细胞和B细胞对这些试剂的反应也无差异。对这些发现最简单的解释是CLL淋巴细胞表面膜上正常反应性酶位点的数量减少，尽管也可能有其他解释。
