TGF-β2对树突状细胞表型和功能的影响

目的: 研究转化生长因子-β2 (TGF-β2)对树突状细胞(dendritic cells, DC)表型和功能的影响. 方法: 体外培养骨髓来源的DC(BMDC)及TGF-β2诱导的DC(TGFβ2-DC). 采用双色免疫荧光化学染色或流式细胞仪(FCM)分析DC的细胞表型. 分离纯化脾脏来源的同种异体T细胞和CD4+ T细胞. 用BMDC及TGFβ2-DC刺激T细胞增殖,并用混合淋巴细胞反应(MLR)测定其能力. 在CD4+ T细胞与BMDC或TGFβ2-DC共培养5 d后,用FCM检测CD4+ T细胞表型的变化. 结果: BMDC表现为CD11c, CD86, MHC class II+和CD8а-的髓系DC. TGF-β2的诱导抑制了DC表面协同刺激分子、MHC classII的表达(P<0.01),并抑制其刺激同种异体T细胞增殖的能力. 与BMDC诱导的CD4+ T细胞相比,TGFβ2-DC诱导的CD4+ T细胞CD152(细胞毒T淋巴细胞相关分子4, CTLA-4)表达上升(P<0.01). 结论: TGF-β2的诱导促使DC表面协同刺激因子表达下降,T细胞合成CTLA-4增加,T细胞的活化和增殖受到明显抑制.     

Molecular and phylogenetic analysis of HIV-1 variants circulating among injecting drug users in Mashhad-Iran

Genetic and phylogenetic information on the HIV-1 epidemic in Middle-East Countries, and in particular in Iran, are extremely limited. By March 2004, the Iranian Ministry of Health officially reported a cumulative number of 6'532 HIV positive individuals and 214 AIDS cases in the Iranian HIV-1 epidemic. The intra-venous drug users (IDUs) represent the group at highest risk for HIV-1 infection in Iran, accounting for almost 63% of all HIV-infected population. In this regards, a molecular phylogenetic study has been performed on a sentinel cohort of HIV-1 seropositive IDUs enrolled at the end of 2005 at the University of Mashhad, the largest city North East of Tehran. The study has been performed on both gag and env subgenomic regions amplified by Polymerase Chain Reaction (PCR) from peripheral blood mononuclear cells (PBMCs) and characterized by direct DNA sequence analysis. The results reported here show that the HIV-1 subtype A is circulating in this IDUs sentinel cohort. Moreover, the single phylogenetic cluster as well as the intra-group low nucleotide divergence is indicative of a recent outbreak. Unexpectedly, the Iranian samples appear to be phylogenetically derived from African Sub-Saharan subtype A viruses, raising stirring speculations on HIV-1 introduction into the IDUs epidemic in Mashhad. This sentinel study could represent the starting point for a wider molecular survey of the HIV-1 epidemics in Iran to evaluate in detail the distribution of genetic subtypes and possible natural drug-resistant variants, which are extremely helpful information to design diagnostic and therapeutic strategies.     

T-cell lymphoma and the Chediak-Higashi syndrome

The majority of patients with Chediak-Higashi syndrome (CHS) develop a lymphoproliferative disorder during the accelerated phase of the disease. Controversy exists regarding the benign versus malignant nature of this cellular proliferation. For the first time, we have characterized the immunologic cell markers on the cellular infiltrate in a lymph node from a patient with CHS. The infiltrate was composed almost entirely of T cells, with histopathologic features consistent with a non-Hodgkin's T-cell lymphoma.     

准分子激光术后超微结构变化与生物组织反应

目的 以超微结构为基础,了解准分子激光表面切削术后角膜生物组织反应特点。方法 透射电镜对38只兔眼4,8,12周角膜组织进行观察和分析,并设对照。结果 角膜基质细胞线粒体和粗面内质网损害;出现功能不良性角膜实质细胞;在各种细胞中有成堆的骶鳞体积聚,提示大量自由基的产生;免疫细胞反应和淋巴细胞的凋亡;气化性碎屑产生;角膜胶原纤维区域性溶解等。结论 准分子激光可使角膜组织产生特异性的生物组织反应,可能是临床合并症的组织病理学基础。