白细胞滤过的血小板预防血小板输注无效和人类白细胞抗原同种免疫反应的Meta分析

目的系统评价白细胞滤过的血小板与标准血小板输注预防血小板输注无效(PTR)和人类白细胞抗原(HLA)同种免疫反应的效果。方法电子检索Medline数据库、EMBASE、The Cochrane Library和CBM收录的白细胞滤过血小板与标准血小板输注的随机或半随机对照试验(截至2009年12月31日),对预防PTR和HLA同种免疫反应的效果进行Meta分析。结果共检索到558篇文献,最终纳入7篇英文研究。Meta分析显示,白细胞滤过的血小板预防PTR的效果优于标准血小板[RR=0.59,95%CI(0.42,0.82),P=0.002],且发生HLA同种免疫反应的风险低于标准血小板输注[RR=0.49,95%CI(0.33,0.74),P=0.0006]。HLA同种免疫反应的风险差异在急性髓细胞样白血病患者中有统计学意义[RR=0.42,95%CI(0.32,0.56),P<0.00001],而在急性淋巴细胞白血病患者中由于样本量有限,尚未发现统计学意义[RR=0.50,95%CI(0.10,2.41),P=0.39]。结论现有研究证据显示输注白细胞滤过的血小板可减少PTR和HLA同种免疫反应的发生,预防效果优于标准血小板。但因纳入研究数量较少、样本量小、方法学质量不高,尚需开展大样本、高质量的研究进一步证实该结果。

人类白细胞免疫球蛋白样受体研究进展

白细胞免疫球蛋白样受体(leukocyte immunoglobulin like receptors,LILRs),是一类具有高度序列同源性的免疫球蛋白超家族,该家族位于人类19号染色体白细胞受体复合体区域,这一区域包含多种免疫球蛋白超家族受体。LILRs包含11个功能基因和2个没有功能的假基因,功能基因根据行使的功能不同又分为2大类:①活化性受体,包含LILRA1-A6;②抑制性受体,包含LILRB1-B5。根据在染色体上的位置不同,LILRs基因簇可以分为着丝粒簇和端粒簇,着丝粒簇和端粒簇从相反的方向转录[1],基因排列顺序如图1所示。

艾滋病治疗重大突破! 科学家成功从人类免疫细胞上移除HIV-1病毒

人类后天免疫不全病毒（HIV）是医学界的恶梦,自病情扩大几十年以来,都还找不出能完全治愈病患的方式,只得以鸡尾酒疗法或服用抗反转录病毒药物（antiretroviral therapy）减缓病情发作,并藉此延长病患寿命。日前,一研究团队用基因编辑技术成功的将HIV-1的去氧核糖核酸（DNA）从人类的免疫细胞上移除,并防止病毒进行进一步的复制与再感染。

2研究发现：T细胞“纳米管”为HIV攻陷免疫搭桥

据2008年1月13日在线发表于《自然一细胞生物学》（NatureCellBiology）上一篇论文报道，英国科学家的一项最新研究发现，人体T细胞之间的丝状联接或许为HIV攻陷人类免疫系统搭了桥。这种被命名为“膜纳米管”（membranenanotubes）的新确定结构有助于解释HIV病毒如何快速有效地感染人类免疫细胞。

研究发现HIV疫苗及治疗药物设计的新思路

加州大学圣地亚哥医学院的研究人员发现HIV感染人类免疫细胞时会在人体及病毒RNA引起大规模的甲基化增长,以帮助病毒复制。该研究揭示了一个控制HIV复制及HIV与机体之间相互作用的新机制。该结果表明,此前研究人员在研发HIV基因靶向药物时犯了一个致命的错误：以未变化的RNA结构为靶点。该研究的相关结果于2016年2月22日发表在《Nature Microbiology》上。

GSK／盐野义完成了新型HIV药物的临床试验

美国Glaxo Smith Kline制药公司与日本盐野义公司已经完成了他们研发的整合酶抑制剂364735（Ⅰ）在人类中进行的初步临床试验，正在评估（Ⅰ）能否作为治疗HIV／AIDS的候选药物，这是两家公司合作内容的一部分。整合酶抑制剂是一类新型的抗HIV药物，该类药物可通过阻止病毒整合到人类免疫细胞基因序列从而阻断病毒复制。

Hepatocellular carcinoma,human immunodeficiency virus and viral hepatitis in the HAART era

The incidence of hepatocellular carcinoma(HCC)in patients with human immunodeficiency virus(HIV) is rising.HCC in HIV almost invariably occurs in the context of hepatitis C virus(HCV)or hepatitis B virus (HBV)co-infection and,on account of shared modes of transmission,this occurs in more than 33% and 10% of patients with HIV worldwide respectively.It has yet to be clearly established whether HIV directly accelerates HCC pathogenesis or whether the rising incidence is an epiphenomenon of the highly active antiretroviral therapy(HAART)era,wherein the increased longevity of patients with HIV allows long-term complications of viral hepatitis and cirrhosis to develop.Answering this question will have implications for HCC surveillance and the timing of HCV/HBV therapy,which in HIV co-infection presents unique challenges.Once HCC develops,there is growing evidence that HIV co-infection should not preclude conventional therapeutic strategies,including liver transplantation.

Secretory Transactivating Transcription-apoptin fusion protein induces apoptosis in hepatocellular carcinoma HepG2 cells

AIM:To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity. METHODS:In this study,we designed a secretory protein by adding a secretory signal peptide(SP) to the N terminus of Transactivating Transcription(TAT)-apoptin(SP-TAT-apoptin),to test the hypothesis that it gains an additive bystander effect as an anti-cancer therapy. We used an artificial human secretory SP whose amino acid sequence and corresponding cDNA sequence were generated by the SP hidden Markov model. RESULTS:In human liver carcinoma HepG2 cells,SP-TAT-apoptin expression showed a diffuse pattern in the early phase after transfection. After 48 h,however,it translocated into the nuclear compartment and caused massive apoptotic cell death,as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay and annexin-V binding assay. SP-TAT-apoptin did not,however,cause any cell death in non-malignant human umbilical vein endothelial cells(HUVECs). Most importantly,the conditioned medium from Chinese hamster ovary(CHO) cells transfected with SP-TAT-apoptin also induced significant cell deathin HepG2 cells,but not in HUVECs. CONCLUSION:The data demonstrated that SP-TAT-apoptin induces apoptosis only in malignant cells,and its secretory property might greatly increase its potency once it is delivered in vivo for cancer therapy.

A low prevalence of H pylori and endoscopic findings in HIV-positive Chinese patients with gastrointestinal symptoms

AIM： To compare the prevalence of H pylori infection, peptic ulcer, cytomegalovirus （CNV） infection and Candida esophagitis in human immunodeficiency virus （HIV）- positive and HIV-negative patients, and evaluate the impact of CD4 lymphocyte on H pylori and opportunistic infections. METHODS： A total of 151 patients （122 HIV-positive and 29 HIV-negative） with gastrointestinal symptoms were examined by upper endoscopy and biopsy. Samples were assessed to determine the prevalence of Hpylori infection, CMV, candida esophagitis and histologic chronic gastritis. RESULTS： The prevalence of Hpylori was less common in HIV-positive patients （22.1%） than in HIV-negative controls （44.8%; P 〈 0.05）, and the prevalence of H pylori displayed a direct correlation with CD4 count stratification in HIV-positive patients. In comparison with HIV-negative group, HIV-positive patients had a lower incidence of peptic ulcer （20.7% vs 4.1%; P 〈 0.01）, but a higher prevalence of chronic atrophy gastritis （6.9% vs 24.6%; P 〈 0.05）, Candida esophagitis and CMV infection. Unlike HIV-negative group, H pylori infection had a close relationship to chronic active gastritis （P 〈 0.05）. In HIV-positive patients, chronic active gastritis was not significantly different between those with Hpylori infection and those without. CONCLUSION： The lower prevalence of H pylori infection and peptic ulcer in HIV-positive patients with gastrointestinal symptoms suggests a different mechanism of peptic ulcerogenesis and a different role of H pylori infection in chronic active gastritis and peptic ulcer. The pathogen of chronic active gastritis in HIV-positive patients may be different from the general population that is closely related to Hpylori infection.

Characterization of the Receptor-binding Domain of Ebola Glycoprotein in Viral Entry

Ebola virus infection causes severe hemorrhagic fever in human and non-human primates with high mortality. Viral entry/infection is initiated by binding of glycoprotein GP protein on Ebola virion to host cells, followed by fusion of virus-cell membrane also mediated by GP. Using an human immunodeficiency virus (HIV)-based pseudotyping system, the roles of 41 Ebola GP1 residues in the receptor-binding domain in viral entry were studied by alanine scanning substitutions. We identified that four residues appear to be involved in protein folding/structure and four residues are important for viral entry. An improved entry interference assay was developed and used to study the role of these residues that are important for viral entry. It was found that R64 and K95 are involved in receptor binding. In contrast, some residues such as I170 are important for viral entry, but do not play a major role in receptor binding as indicated by entry interference assay and/or protein binding data, suggesting that these residues are involved in post-binding steps of viral entry. Furthermore, our results also suggested that Ebola and Marburg viruses share a common cellular molecule for entry.

Decreased mitochondrial deoxyribonucleic acid and increased oxidative damage in chronic hepatitis C

AIM： To determine whether alteration of the mito- chondria DNA （mtDNA） copy number and its oxidative damage index （mtDNA△CT） can be detected by analysis of peripheral blood cells in hepatitis C virus （HCV）- infected patients. METHODS： This study enrolled two groups of pa- tients aged 40-60 years： a control group and an HCV- infected group in Department of Gastroenterology and Hepatology in Changhua Christian Hospital. Patients with co-infection with hepatitis B virus or human im- munodeficiency virus, autoimmune disease, malignant neoplasia, pregnancy, thyroid disease, or alcohol con- sumption 〉 40 g/d were excluded. HCV-infected pa- tients who met the following criteria were included： （1） positive HCV antibodies for 〉 6 mo; （2） alanine aminotransferase （ALT） levels more than twice the upper lim- it of normal on at least two occasions during the past 6 mo; and （3） histological fibrosis stage higher than F1. The mtDNA copy number and oxidative damage index of HCV mtDNA （mtDNA△CT） were measured in periph- eral blood leukocytes. The association between mtDNA copy number and mtDNA△CT was further analyzed using clinical data. RESULTS： Forty-seven normal controls （male/female： 26/21, mean age 50.51 ± 6.15 years） and 132 HCV- infected patients （male/female： 76/61, mean age 51.65 ± 5.50 years） were included in the study. The geno- types of HCV-infected patients include type 1a （n = 3）, type 1b （n = 83）, type 2a （n = 32）, and type 2b （n = 14）. Liver fibrosis stages were distributed as follows： F1/F2/F3/F4 = 1/61/45/25 and activity scores were A0/ A1/A2/A3 = 7/45/55/25. There were no age or gender differences between the two groups. HCV-infected pa- tients had higher hepatitis activity （aspartate transami- nase levels 108.77 ± 60.73 vs 23.19 ± 5.47, P 〈 0.01; ALT levels 168.69 ± 93.12 vs 23.15 ± 9.45, P 〈 0.01） and lower platelet count （170.40±58.00 vs 251.24 ± 63.42, P 〈 0.01） than controls. The mtDNA copy num- ber was lower in HCV-infected patients than in controls （173.49 vs 247.93, P 〈 0.05）. The mtDNA△CT was higher in HCV-infected patients than in controls （2.92 vs 0.64, P 〈 0.05）. To clarify the clinical significance of these results in HCV-infected patients, their association with different clinical parameters among HCV-infected pa- tients was analyzed. A negative association was found between mtDNA copy number and elevated aspartate transaminase levels （r = -0.17, P 〈 0.05）. Changes in mtDNA copy number were not associated with HCV RNA levels, HCV genotypes, liver fibrosis severity, or inflammatory activity in the liver biopsy specimen. How- ever, a correlation was observed between mtDNA△CT and platelet count （r = -0.22, P 〈 0.01）, HCV RNA level （r = 0.36, P 〈 0.01）, and hepatitis activity （r = 0.20, P = 0.02）. However, no difference in the change in mtDNA△CT was observed between different fibrosis stages or HCV CONCLUSION： Oxidative stress and mtDNA dam- age are detectable in patient＇s peripheral leukocytes. Increased leukocyte mtDNA△CT correlates with higher HCV viremia, increased hepatitis activity, and lower platelet count.

Microscopic colitis

Microscopic colitis may be defined as a clinical syndrome, of unknown etiology, consisting of chronic watery diarrhea, with no alterations in the large bowel at the endoscopic and radiologic evaluation. Therefore, a definitive diagnosis is only possible by histological analysis. The epidemiological impact of this disease has become increasingly clear in the last years, with most data coming from Western countries. Microscopic colitis includes two histological subtypes [collagenous colitis (CC) and lymphocytic colitis (LC)] with no differences in clinical presentation and management. Collagenous colitis is characterized by a thickening of the subepithelial collagen layer that is absent in LC. The main feature of LC is an increase of the density of intra-epithelial lymphocytes in the surface epithelium. A number of pathogenetic theories have been proposed over the years, involving the role of luminal agents, autoimmunity, eosinophils, genetics (human leukocyte antigen), biliary acids, infections, alterations of pericryptal fibroblasts, and drug intake; drugs like ticlopidine, carbamazepine or ranitidine are especially associated with the development of LC, while CC is more frequently linked to cimetidine, non-steroidal antiinflammatory drugs and lansoprazole. Microscopic colitis typically presents as chronic or intermittent watery diarrhea, that may be accompanied by symptoms such as abdominal pain, weight loss and incontinence. Recent evidence has added new pharmacological options for the treatment of microscopic colitis:the role of steroidal therapy, especially oral budesonide, has gained relevance, as well as immunosuppressive agents such as azathioprine and 6-mercaptopurine. The use of anti-tumor necrosis factoragents, infliximab and adalimumab, constitutes a new, interesting tool for the treatment of microscopic colitis, but larger, adequately designed studies are needed to confirm existing data.

Preparation of BFV Gag Antiserum and Preliminary Study on Cellular Distribution of BFV

Viruses (e.g. Human immunodeficiency virus, Human simplex virus and Prototype foamy virus) are obligate intracellular parasites and therefore depend on the cellular machinery for cellular trafficking. Bovine foamy virus (BFV) is a member of the Spumaretrovirinae subfamily of Retroviruses, however, details of its cellular trafficking remain unknown. In this study, we cloned the BFV gag gene into prokaryotic expression vector pET28a and purified the denaturalized Gag protein. The protein was used to immunize BALB/c mouse to produce antiserum, which could specifically recognize the BFV Gag protein in BFV-infected cells through western blot assay. Additionally, these results demonstrated that both the optimal and suboptimal cleavage of Gag protein occur in BFV-infected cells. Subsequently, the Gag antiserum was used to investigate subcellular localization of BFV. In immunofluorescence microscopy assays, colocalization microtubules (MTs) and assembling viral particles were clearly observed, which implied that BFV may transport along cellular MTs in host cells. Furthermore, MTs-depolymerizing assay indicated MTs were required for the efficient replication of BFV. In conclusion, our study suggests that BFV has evolved the mechanism to hijack the cellular cytoskeleton for its replication.

Prediction of HLA-A 2.1-restricted CTL epitopes from IGFBP7 antigen of lung carcinoma

Objective： With the development of peptide-based cancer specific immunotherapy, the prediction of CTL epitopes from insulin-like growth factor-binding protein 7 （IGFBP7） is very important for some research about tumor metastasis. Because HLA-A2.1-expressing individuals cover 〉50% in the population of China, we aimed at identifying IGFBPT-encoded peptide presented by HLA-A2.1. Methods： In our study, a HLA-A2.1 restricted CTL epitope was identified by using the following two-step procedure： （a） computer-based epitope prediction from the amino acid sequence of IGFBP7 antigen; （b） Validation with epitope molecular modeling. Results： We obtained four epitopes with high immunogenicity scores by all of the three algorithms, i.e., BIMAS, SYFPEITH1 and IMTECH. Each of the four candidates satisfied the criteria of the HLA-A2.1- restricted CTL epitopes in molecular modeling analysis. Conclusion： The combination of BIMAS, SYFPEITHI and IMTECH method can improve the prediction efficiency and accuracy. Due to this research herein, this four epitopes have potential value for further studied, also have potential application in peptide-mediated immunotherapy. These epitopes may be useful in the design of therapeutic peptide vaccine for lung carcinoma and as immunotherapeutic strategies against lung carcinoma after identified by immunology experiment.

Driving Forces of AIDS Pathogenesis:Massive CD4^+ T Lymphocyte Depletion and Abnormal Immune Activation

The occurrence of massive CD4+ T cell depletion is one of the most prominent characteristics of human immunodeficiency virus type 1 (HIV-1) infection during acute phase, resulting in unrestorable destruction to the immune system. The infected host undergoes an asymptomatic period lasting several years with low viral load and ostensibly healthy status, which is presumably due to virus-specific adaptive immune responses. In the absence of therapy, an overwhelming majority of cases develop to AIDS within 8-10 years of latent infection. In this review, we discuss the roles in AIDS pathogenesis played by massive CD4+ T lymphocytes depletion in gut-associated lymphoid tissue (GALT) during acute infection and abnormal immune activation emerging in the later part of chronic phase.

Expression of proto-oncogene Fra-1 in human neoplastic breast tissues

Objective： Invasion and metastasis are the most significant and intrinsic biological characteristics of cancers, also which are main factors of malignant tumor causing treatment failure and death. Recent studies have found that Fra-1 plays an important role on cell migration, invasion, and maintaining malignant phenotype of transformed cells. But there are few stud- ies about the expression and location of Fra-1 in breast tissues and cells being reported .This study just aims to discuss the expression and location of transcription factor Fra-1 in benign and malignant human breast tissues. Methods： The expression of Fra-1 was investigated by immunohistochemistry in neoplastic breast diseases ranging from benign fibroadenoma to very aggressive undifferentiated carcinoma. The correlations of Fra-1 expression with other indicators of breast carcinoma prog- nosis （ER, PR and ErbB2 receptors） were analyzed. Results： All neoplastic breast tissues, either benign or malignant breast tissues, were nuclear immunoreactive for Fra-l-recognizing antibody. In 85% of benign tumors （17/20）, the immunoreactive for Fra-l-recognizing antibody as exclusively restricted to the nuclei. In three cases （3/20, 15%）, focal unequivocal cytoplas- mic staining was also exhibited. Strong positive nuclear staining for Fra-1 was easily seen in all types of breast carcinomas. However the nucleaflcytoplasmic concomitant immunoreactivity was observed in all types of breast carcinomas. A clear shift in Fra-1 immunoreactivity, from an exclusively nuclear to a simultaneous nuclear and cytoplasmic localization was noticed in 90.2% （37/41） of breast carcinomas. No inverse relationship between Fra-1 and ER and PR protein levels was noticed in malignant tumors. The relative expression level of Fra-1 was not correlated with the expression of ErbB2. Conclusion： The overall expression, pattern and intensity of Fra-1 proteins were correlated with breast oncogenesis. Overexpression of Fra-1, leading to a persistent high cytoplasmic accumulation, may play a role in the process of breast carcinogenesis.

Phagocytosis of IgA Immune Complexes by Human U937 Cells

In order to study FcαRⅠ mediated phagocytosis of IgA immune complexes by U937 cells, antigen 8.9NIP/BSA was labeled with FITC and reacted with anti-NIP IgA or anti-NIP IgG antibody to form immune complexes (ICs). They were then incubated with phorbol 12-myristate 13-acetate (PMA) stimulated U937 cells.The phagocytosed ICs were quantified by flow cytometry. The results was that the expression of FcαRⅠ on U937 cells was higher than that of FcγRⅠ, FcγRⅡ and FcγRⅢ. After stimulation by PMA, expression of FcαRⅠ on U937 cells was markedly upregulated and the phagocytosis of IgA ICs was enhanced. FcαRⅠ mediated specific IgA phagocytosis was stronger than FcγRⅠ and FcγRⅡ mediated IgG phagocytosis. Complement receptors, CR1 and CR3, enhanced U937 cell phagocytosis of IgA ICs. It concludes that FcαRⅠ mediated strong phagocytosis of IgA ICs.

Functional study of p38 mitogen-activated protein kinase based on cell-penetrating peptide delivery system

Objective p38 Mitogen-activated protein kinase （MAPK） is a crossing center of various pathways. In this study, protein transduction system based on human immunodeficiency virus （HIV）-1 transactivator of transcription （TAT）, which is an efficient delivery peptide of the foreign proteins into cells, was employed to study p38 MAPK functions in eukaryotic cells. Methods p38 And its dominant negative form, p38AF, were constructed into pET-His-TAT vector correctly to verify that the recombinant plasmids were well-founded through restriction enzyme digestion and DNA sequencing. The two proteins, His-TAT-p38 and His-TAT-p38AF, were expressed and purified in Escherichia coli by SDS-PAGE. Then they were incubated with ECV304 cells respectively and readily transduced into cells in a time-dependent and dose-dependent manner. The cells were stimulated by sorbitol. Activating transcription factor （ATF） 2 phosphorylation level was checked using Western blot to assess the activity of endogenous p38. Results Compared with controls, it was found that His-TAT-p38 increased the level ofATF2 phosphorylation in sorbitol-stimulated ECV304 cells, while His-TAT-p38AF inhibited it, indicating p38 MAPK protein delivery system based on TAT was constructed successfully. TAT-p38 and its dominant negative form possessed high biological activity after transduction into ECV304 cells by TAT protein delivery system. The results showed that p38AF fused with TAT could inhibit the transduction of endogenous p38 signal pathway in part, and other pathway might regulate p38 phosphorylation. Conclusions Our study provides a novel pathway to inhibit p38 signal pathway and establish a new method to study p38 function.

HIV感染者可以接种疫苗吗

由于人类免疫缺陷病毒(HIV)攻击人类免疫细胞的特点,HIV感染者常对疫苗接种的安全性及有效性有诸多疑虑。HIV感染者究竟能不能、该不该接种疫苗?如何接种呢?

医海拾贝

人们在肠道和肺组织中发现了一种新型人类免疫细胞。这类细胞影响到哮喘和过敏反应的严重程度，表达的细胞标志物为CRTH2、CD127和CD161，使其有别于肠道和肺中的其他细胞。这类细胞被激活后，会引发过敏性免疫反应。例如，慢性鼻窦炎患者的激活CRTH2阳性细胞数量较多。