Efficient depletion of alloreactive donor T lymphocytes based on expression of two activation-induced antigens (CD25 and CD69)

T lymphocytes play an important role in allogeneic bone marrow/stem cell transplantation by supporting engraftment and immune recovery. Moreover, donor T cells have been shown to mediate the so-called graft-versus-leukaemia effect and are, therefore, increasingly used for adoptive immunotherapy. However, T-cell infusions are associated with the risk of a graft-versus-host reaction, which may lead to a life-threatening disease. To overcome this problem, we followed a new strategy for the exclusive depletion of alloreactive cells. We activated allogeneic T cells by cultivation on an adherent cell layer derived from peripheral blood. We then depleted activated cells based on the expression of CD25, CD69 or both activation-induced antigens using magnetic cell sorting. Mixed lymphocyte culture (MLC) reactions and helper T-lymphocyte precursor cell frequency (HTLP-f) assays demonstrated that this technique led to a significant decrease in alloreactivity of 'donor' cells, which at the same time preserved reactivity against third-party cells. The lowest level of alloreactivity was found when CD25 and CD69 antibodies were used together for depletion. This corresponds with our observation that expression of CD25 or CD69 may partially represent different activation pathways. We conclude that ex vivo depletion of CD25- and CD69-expressing alloreactive cells may help to overcome limitations of adoptive immunotherapy.     

Durable remission induced by rituximab-containing chemotherapy in a patient with primary refractory Burkitt's lymphoma

We describe a 65-year-old man diagnosed with Burkitt's lymphoma arising from the intestine. The tumor cells had a mature B-cell immunophenotype and rearrangement of the c-myc gene. The patient was treated with intensive multiagent chemotherapy. After four courses of chemotherapy, an ileus developed due to a residual abdominal disease. We administered rituximab in combination with the same chemotherapy regimen. A dramatic clinical improvement was observed and abnormal uptake by 18F-fluorodeoxyglucose positron emission tomography disappeared. The patient experienced complete remission for 1 year. This encouraging result indicates that rituximab might be an important treatment choice in management of Burkitt's lymphoma.     

160例成人HIV感染者/AIDS患者机会性感染与CD4+之间关系分析

目的：分析中国成人艾滋病病毒（HIV）感染者／艾滋病（AIDS）患者机会性感染发生的频率与CD4^ 细胞数之间的关系。方法：对1990－2001年在北京佑安医院就诊的160例成人HIV感染者／AIDS患者CD4^ 、CD8^ 进行跟踪分析。结果：（1）CD4^ ＞500个／μl66人次（12．7％），CD4^ 为200个／μl-500个／μl212人次（41．1％），CD4^ ＜200个／μl234人次（45．3％）。在CD4^ ＜个200／μl中，CD4^ ＜100个／μl128人次（24．8％），CD4^ ＜50个／μl89人次（17．2％）。（2）CD4^ ＞200个／μl时，共发生机会性感染33人次（15．6％）。CD4^ ＜200个／μl时，共发生机会性感染170人次（72．6％），CD4^ 为100个／μl0－200个／μl之间发生机会性感染42人次（39．6％），CD4^ ＜100个／μl发生机会性感染128人次（98．4％），其中CD4^ ＜50个／μl发生机会性感染87人次（97．8％）。结论：中国成人HIV感染者／AIDS患者在CD4^ ＞200个/μl时机会性感染出现频率较少，CD4^ ＜200个／μl时机会性感染的频率明显增加，CD4^ ＜100个／μl和＜50个／μl时，感染率约为100％。     

Phosphorylation of human cardiac troponin I G203S and K206Q linked to familial hypertrophic cardiomyopathy affects actomyosin interaction in different ways

cAMP-dependent protein kinase (PKA)-dependent phosphorylation of the two serine residues in the amino terminal region unique to cardiac troponin I (cTnI) is known to cause two effects: (i) decrease of the maximum Ca2+-controlled thin filament-activated myosin S1-ATPase (actoS1-ATPase) activity and mean sliding velocity of reconstituted thin filaments; (ii) rightward shift of the Ca2+ activation curves of actoS1-ATPase activity, filament sliding velocity, and force generation. We have studied the influence of phosphorylation of human wild-type cTnI and of two mutant cTnI (G203S and K206Q) causing familial hypertrophic cardiomyopathy (fHCM) on the secondary structure by circular dichroism spectroscopy and on the Ca2+ regulation of actin-myosin interaction using actoS1-ATPase activity and in vitro motility assays. Both mutations slightly influence the backbone structure of cTnI but only the secondary structure of cTnI-G203S is also affected by bis-phosphorylation of cTnI. In functional studies, cTnI-G203S behaves similarly to wild-type cTnI, i.e. the mutation itself has no measurable effect and bis-phosphorylation alters the actoS1-ATPase activity and the in vitro thin filament motility in the same way as does bis-phosphorylation of wild-type cTnI. In contrast, the mutation K206Q leads to a considerable increase in the maximum actoS1-ATPase activity as well as filament motility compared to wild-type cTnI. Bis-phosphorylation of this mutant cTnI still suppresses the maximum actoS1-ATPase activity and filament sliding velocity but does no longer affect the Ca2+ sensitivity of these processes. Thus, these two fHCM-linked cTnI mutations, although reflecting similar pathological situations, exert different effects on the actomyosin system per se and in response to bis-phosphorylation of cTnI.     

CD14 promoter polymorphism in Chinese alcoholic patients with cirrhosis of liver and acute pancreatitis

AIM: To investigate the relationship between genetic polymorphism of the CD14 promoter and the occurrence of alcoholic cirrhosis and alcoholic pancreatitis, and to challenge the conclusion made earlier that the patients with acute alcoholic pancreatitis and patients with alcoholic cirrhosis of liver are two different subpopulations. METHODS: Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, we determined the polymorphism of CD14 gene and aldehyde dehydrogenase gene 2 (ALDH 2) in 335 alcoholic patients with different organ complications i.e., cirrhosis of liver (n = 100), acute pancreatitis (n = 100), esophageal cancer (n = 82) and avascular necrosis of hip joint (AVN) (n = 53) and 194 non-alcoholic controls in a Chinese group. RESULTS: The results showed that the carriage of T allele was not different among alcoholic patients with cirrhosis of liver, alcoholic patients with other complication and non-alcoholic controls. On the other hand, the carriage of the C allele was significantly more prevalent for alcoholic pancreatitis than for esophageal cancer (0.79 vs 0.60, P<0.001), alcoholic AVN (0.79 vs 0.65, P<0.025) and nonalcoholic controls (0.79 vs 0.68,P<0.025). Furthermore, when only subjects with ALDH2 1-1 genotype were examined, the C allele frequency was significantly more prevalent for alcoholic pancreatitis than for alcoholic liver cirrhosis (0.82 vs 0.69,P<0.025), esophageal cancer (0.82 vs 0.61,P><0.01), alcoholic AVN (0.82 vs 0.64, P<0.01) and non-alcoholic controls (0.82 vs 0.69, P<0.05). CONCLUSION: The C allele may be associated with some mechanism, which is important in the pathogenesis of alcoholic pancreatitis, and that alcoholic patients with acute pancreatitis and cirrhosis of liver are probably two different subpopulations.     

Solitary fibrous tumor of the liver

We report a new case of benign solitary fibrous tumor (SFT) of the liver. A 65‐year‐old man presented to our unit with upper right abdominal discomfort. On examination abdominal distension was present and palpation showed a large firm mass in the right hypochondrium and epigastrium. The patient's past medical history was not significant and laboratory tests were normal. Ultrasonography and computed tomography showed a large tumor, 20 cm in diameter, in the right lobe of the liver. An extended right hepatectomy was performed. The tumor measured 30 × 28 × 14 cm and weighed 4725 g. Microscopic evaluation showed a benign SFT of the liver with tumor cells typically positive for vimentin and CD34. The postoperative course was uneventful, and the patient is alive 30 months after surgery. This is a rare neoplasm of mesenchymal origin that occasionally involves the liver in adult patients. Most SFTs are benign, but some may have malignant histological features and recur locally or metastasize. Because of their rarity, overall experience has not been significant and little has been published concerning this tumor, Including the present one, 28 cases have been reported in the English literature. Surgery is the mainstay of treatment. Little can be said about the benefits of adjuvant radiochemotherapy in these patients. As SFT of the liver is often a benign neoplasm, chemotherapy or radiotherapy should not be necessary, and should be reserved for when resection is incomplete and/or histological examination reveals features of malignancy. Surgeons must be aware of SFT of the liver, and this neoplasm should be included in the differential diagnosis of a single large hepatic mass.     

慢性淋巴细胞白血病CD5漏检临床案例分析及对策

目的分析不同荧光素标记抗体对慢性淋巴细胞白血病(CLL)B细胞表面CD5检测结果差异及其对临床诊断的影响。方法采用流式细胞仪检测3例CD5表达强度不同的慢性淋巴细胞白血病(CLL)患者的免疫表型,采用SYSMEX XE2100全自动血液分析仪检测血常规;以1例急性B淋巴细胞白血病(B-ALL)患者作为阴性对照。结果采用异硫氰酸荧光素(FITC)标记抗体检测4例患者骨髓异常B淋巴细胞CD5表达,CD5阳性细胞未见独立成群,阳性细胞比例分别为47.1%、17.7%、6.7%和7.9%;以≥20%为标准,仅病例1阳性。以PE-Cy7荧光素标记抗体重新检测,病例1和2的CD5阳性细胞独立成群,病例3 CD5表达呈连续表达模式,阳性细胞比例分别上升至91.1%、70.3%和38.2%。而对照病例4(B-ALL患者)2次检测CD5比例均为阴性。病例1、2、3符合典型CLL免疫表型。结论 CLL患者B细胞表面常异常表达CD5,但其表达强度显著低于T细胞表面CD5表达。采用弱荧光素标记抗体检测B细胞表面CD5表达,会出现漏检进而影响临床诊断。对弱表达抗原选择合适的荧光素标记,并进行验证和比对确定其准确性,是正确提供疾病免疫表型的重要保障。     

小鼠白细胞免疫球蛋白样受体2干扰RNA对树突状细胞表面CD11c、CD80和CD86的影响及意义

目的探讨小鼠树突状细胞(DC)表面白细胞免疫球蛋白样受体2(LILRB2)改变对DC的CD11c、CD80和CD86表型的影响及意义。方法应用20 ng/ml重组小鼠粒细胞集落刺激因子(r GM-CSF)+20 ng/ml IL-4刺激小鼠骨髓细胞生长,隔日进行细胞换液,第5天实验组转染LILRB2受体干扰RNA,空白对照组转染空质粒,对照组单纯换液。培养过程中观察细胞形态学变化,并于转染72 h后,光镜下观察DC形态,用流式细胞仪测定细胞表面CD11c、CD80和CD86分子表达。结果光镜下对照组与实验组均可见DC细胞形态,流式细胞仪测定实验组CD11c(0.662±0.174)(n=12)与空白对照组CD11c(0.675±0.237)和对照组(0.688±0.076)分子表达无明显差异(P>0.05)。实验组DC细胞表面CD80(0.626±0.060)较空白对照组CD80(0.406±0.163)(n=12)和对照组CD80(0.409±0.100)表达均增加(P<0.05)。实验组DC细胞表面CD86(0.730±0.102)较空白对照组CD86(0.497±0.278)和对照组CD86(0.368±0.073)表达均增加(P<0.05)。结论应用LILRB2受体干扰RNA不影响DC细胞表面CD11c分子表达,而增加细胞表面CD80和CD86分子表达。细胞表面CD80和CD86分子作为免疫反应的重要协同刺激分子在抗原提呈细胞表面表达升高,则激活T细胞免疫反应的能力增强。