Blood lymphocyte subsets in ATG-treated and allografted rats

Abstract. A single dose of rabbit antithymocyte globulin (ATG) was given as the sole immunosuppressive therapy in a model of strong MHC barrier rat heart allotransplantation. PVG/c hearts transplanted to Wistar/Kyoto (WKy) rats resulted in long-term surviving (LTS) grafts and cell-mediated lympholysis (CML) unresponsiveness in 50% of the animals. The effects of ATG treatment on the peripheral blood lymphocyte subsets were studied by flow cytometry. The absolute T-lymphocyte levels decreased to less than 5% and were normalized after 2 weeks. CD8-positive cells were normalized within 1 week, whereas CD4-and CD5-positive cells remained low. Rats with LTS grafts had low levels of all T-lymphocyte markers, especially the CD4-and CD5-positive cells. Rats rejecting their grafts showed an eightfold increase in levels of CD8-and CD5-positive lymphocytes and a twofold increase in levels of CD4-expressing lymphocytes. It is concluded that ATG treatment causes the immediate elimination of large lymphoid populations as well as long-lasting immunomodulation detectable in peripheral blood.     

Epitope Context and Reshaping of Activated T Helper Cell Repertoire

In recent years, a growing interest in the study of peptide antigenicity in relation to the role of flanking sequences and protein topology in processing, presentation, and recognition has been observed. However, the information available on the antigenicity of recombinant fusion proteins and their effect on the selection of antigen receptor repertoires is limited. To analyze the role of molecular topology of T epitopes in a system relevant to human pathology, we have used the bacterially expressed Schistosoma japonicum glutathione S transferase (GST) to construct recombinant antigens containing HIV-1 derived T cell determinants, and human T cell clones specific for these determinants. We found that antigenicity of a given GST—peptide combination was not the same when T cells and antigen presenting cells from different individuals were tested. Our results show that differences in processing and presentation of chimeric proteins are not dictated by the use of diverse restriction elements. We also found that the context in which an antigenic peptide is delivered affects the recruited repertoire as defined according to T cell receptor Vβ usage and fine specificities of selected T cells.     

神经胶质瘤患者细胞免疫的近代实验研究

本文检测了40例脑胶质瘤患者淋巴细胞亚群、NK细胞杀伤活性、淋巴细胞增殖率以及免疫抑制活性的变化,与正常对照组(40例)相比较,该四项免疫学指标均有显著性差异(均P<0.001),并阐述了患者细胞免疫功能低下可能与患者血清免疫抑制因子有关。     

Analysis of T Cell Receptor Variability in Fresh Tumor-infiltrating Lymphocytes from Human Head and Neck Cancer

In this study, we analyzed T cell receptor (TCR) gene rearrangements in tumor-infiltrating lymphocytes (TIL) freshly obtained from 15 patients with head and neck cancer using the reversely transcribed polymerase chain reaction (RT-PCR) method. These TILs showed preferential expression of Vα10, Vα8 and Vα1, detected in 13 (87%), 11 (73%), and 9 cases (60%), respectively. The TCRVβ gene revealed diversity without preferential usage. The head and neck region is exposed to bacteria and viruses, so it is possible that the tumor site can become infected and accumulate T cells involved in infection and inflammation. Therefore, we also investigated TCR gene usage in T cells infiltrating in chronic sinusitis mucosa to address the question of whether the Vα1, Vα8, and Vα10 subfamilies are characteristic in TIL from squamous cell carcinoma of head and neck. TCR Vα10 gene usage was also the most common in Vα segment in T cells infiltrating the sinus mucosa, but Vα and Vα8 were not detected in the T cells in sinusitis. These results indicate that the Vα10 subfamily, the preferred T cell population in both TIL and T cells in inflammatory disease, might he involved mainly in inflammation or infection. On the other hand, Vα1 and Vα8 appear to be relatively specific populations for antitumor immunity in head and neck cancer.     

单克隆抗体在淋巴细胞白血病中的临床应用

本实验应用二十一种抗人白细胞分化抗原的单克隆抗体。通过ABC(avidin-biotin peroxidase complex)免疫酶标方法对十二例淋巴细胞白血病病人进行了免疫表型分析。提示单克隆抗体在淋巴细胞白血病病人的临床分型、治疗及预后估计上很有意义。粒、淋双表达白血病其本质不明,因而治疗上至今还没有一个理想的方案。     

皮质类固醇对哮喘患者T淋巴细胞亚群的影响

应用Ｔ淋巴细胞亚群单克隆抗体对类固醇治疗前后哮喘患者外周血Ｔ淋巴细胞亚群的变化进行检测，结果提示：类固醇治疗后ＯＫＴ８较治疗前增高，ＯＫＴ４／ＯＫＴ８比值较治疗前降低并且接近正常，说明Ｔ淋巴细胞是类固醇作用的靶细胞，类固醇可直接影响Ｔ细胞亚群分布，发挥其非特异性抗炎作用。     

人外周血单核细胞和脐血CD34+细胞来源的树突细胞比较

目的比较从人外周血单核细胞及脐血CD34+细胞诱导树突细胞(DC)的方法及其特性.方法用淋巴细胞分离液分离外周血单个核细胞,贴壁法获得单核细胞;经GM-CSF及IL-4诱导获得DC.磁性活化细胞分选系统(MACS)分选脐血CD34+细胞,以GM-CSF、IL-4、TNF-α、SCF、FL、TPO等细胞因子诱导获得DC.用电镜、普通显微镜观察DC形态;流式细胞仪分析DC表型;同种混合淋巴细胞反应(allo-MLR)观察DC刺激T淋巴细胞增殖的能力.结果外周血单核细胞在因子GM-CSF、IL-4、TNF-α,脐血CD34+细胞在GM-CSF、IL-4、TNF-α、SCF、FL、TPO等因子作用下,可生成DC,并表达相应的DC分化抗原CD14、CD80、CD83、CD86、HLA-DR.脐血CD34+细胞具有较强的扩增能力,经2周诱导,体系细胞数可增加173.8士26.7倍,两种来源的DC均能刺激同种异体淋巴细胞的增殖反应.结论外周血单核细胞与脐血CD34+细胞,在体外均可诱导成DC,并具有相应的DC分化抗原和功能.     

抗鼠T淋巴细胞血清的制备

目的 根据小鼠神经元与T淋巴细胞具有共同抗原Thy-1的特点，利用鼠脑组织制备兔抗鼠T淋巴细胞血清。方法 提取鼠脑组织与弗氏完全佐剂混合，制成油包水乳剂， 免疫2只家兔后，采血，分离血清，用鼠脾淋巴细胞做凝集试验及补体依赖的细胞毒试验确定其活性。结果 制备的抗血清可与鼠脾淋巴细胞发生反应，2只兔抗血清凝集试验的效价分别为1：640及1：1280。抗血清1：320倍稀释后与鼠脾淋巴细胞做补体依赖的细胞毒试验，特异性细胞毒性均为32％。结论 用鼠脑组织制备抗鼠T淋巴细胞血清是一种可行的方法。     

Preselection Thymocytes Are More Sensitive to T Cell Receptor Stimulation Than Mature T Cells

During T cell development, thymocytes which are tolerant to self-peptides but reactive to foreign peptides are selected. The current model for thymocyte selection proposes that self-peptide–major histocompatibility complex (MHC) complexes that bind the T cell receptor with low affinity will promote positive selection while those with high affinity will result in negative selection. Upon thymocyte maturation, such low affinity self-peptide–MHC ligands no longer provoke a response, but foreign peptides can incidentally be high affinity ligands and can therefore stimulate T cells. For this model to work, thymocytes must be more sensitive to ligand than mature T cells. Contrary to this expectation, several groups have shown that thymocytes are less responsive than mature T cells to anti-T cell receptor for antigen (TCR)/CD3 mAb stimulation. Additionally, the lower TCR levels on thymocytes, compared with T cells, would potentially correlate with decreased thymocyte sensitivity. Here we compared preselection thymocytes and mature T cells for early activation events in response to peptide–MHC ligands. Remarkably, the preselection thymocytes were more responsive than mature T cells when stimulated with low affinity peptide variants, while both populations responded equally well to the antigenic peptide. This directly demonstrates the increased sensitivity of thymocytes compared with T cells for TCR engagement by peptide–MHC complexes.     

Effect of iodine isotope on the pituitary-thyroid and immune systems of children living on the territories polluted by radionuclides

Examination of thyroid function and immune status of children living on the territories polluted by radionuclides in 1993–1994 revealed¹³¹I-dependent thyroid autoimmune reactions. These data indicate a possible effect of¹³¹I on the pituitary-thyroid and immune systems of children living on the radiation controlled territories. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 8, pp. 216–220, August, 1998