同种异基因骨髓细胞移植诱导嵌合体小鼠生成

采用C57BL/J和BALB/c两种小鼠进行骨髓细胞移植。移植前受体小鼠经 6 0Gy6 0 Coγ射线照射。用细胞染色法和流式细胞术分析了射线对小鼠淋巴细胞的损伤强度和照射后移植了骨髓细胞的小鼠在不同时间内的淋巴细胞亚群变化。结果表明 ,(1 ) 6 0Gyγ射线照射受体鼠 ,能杀伤 95 5 %的外周淋巴细胞 ,但是不影响自身H 2Kb 分子在淋巴细胞表面表达的百分数。残留细胞中CD3+ T细胞、NK1 1 + 淋巴细胞、CD3+ /NK1 1 + 淋巴细胞的阳性率分别由照射前的 40 44%增加到45 30 %、 1 1 3 %增加到 37 41 %和 1 0 7%增加到 5 86 % (P≤ 0 0 1 ) ;(2 )小鼠的淋巴细胞数量从照射后 30d开始恢复 ,到1 90d达到正常值 ;(3 )照射后进行同种异基因骨髓细胞移植后的第 60天 ,受体淋巴细胞表面自身H 2Kb 抗原表达下降 ,CD3+ /NK1 1 + 淋巴细胞百分数增加。随H 2Kb 的抗原表达的恢复 ,CD3+ /NK1 1 + 淋巴细胞百分数下降 ;(4)在细胞移植的第 1 90天 ,受体小鼠 (黑色 )表型呈现出供体鼠 (白色 )颜色特征。在嵌合体小鼠外周淋巴细胞中 ,有 2 5 %为供体H 2Kd 阳性细胞 ,CD3+ /NK1 1 + 淋巴细胞百分数为 1 88% ,明显高于正常值 (P≤ 0 0 1 )。以上结果表明 ,6 0Gy6 0 Coγ射线照射能诱导免疫耐受 ,其耐受性的形成可能与最初保     

CD8+CD28-Ts、CD3+CD56+NKT细胞在B细胞非霍奇金淋巴瘤患者外周血中分布的分析

背景及目的:目前认为B细胞非霍奇金淋巴瘤(B-NHL)常伴随免疫抑制,CD8 CD28-Ts(Ts)细胞和CD3 CD56 NKT(NKT)是新鉴定的新型免疫抑制性调节细胞,在肿瘤的免疫抑制及免疫逃逸机制中起重要作用,但它们在B细胞淋巴瘤患者外周血的分布情况及其免疫抑制中的作用目前尚不清楚。本文通过分析两者在化疗前及化疗后B-NHL患者外周血中比例及变化规律,初步探讨它们在B-NHL的免疫抑制作用及其影响因素,为有效干预患者的免疫功能提供参考。方法:应用流式细胞仪检测79例治疗前的B-NHL患者、经4～6周期化疗后完全缓解(CR)的18例患者、30例健康志愿者外周静脉血中NKT及Ts细胞的比例。结果:在79例治疗前B-NHL患者的外周血中,Ts细胞比例为(18.19±5.03)%,较正常对照组(11.20±3.49)%明显增高(P<0.01);NKT的比例为(6.08±3.29)%,亦较正常对照组的(3.52±1.56)%明显增高(P<0.01)。Ts在不同临床分期的患者之间无显著性差异P>0.05;Ⅰ期为(17.56±4.10)%、Ⅱ期为(18.05±5.64)%、Ⅲ期为(18.14±5.58)%、Ⅳ期为(18.95±4.64)%;在不同恶性程度的患者之间亦无显著性差异P>0.05;低度恶性为(17.81±5.24)%、中度恶性为(18.37±4.83)%、高度恶性为(18.31±5.93)%;在治疗前(18.64±4.55)%和CR后(19.42±4.95)%患者之间亦无显著性差异(P=0     

Assessment of intracellular cytokines and regulatory cells in patients with autoimmune diseases and primary immunodeficiencies — Novel tool for diagnostics and patient follow-up

Serum and intracytoplasmic cytokines are mandatory in host defense against microbes, but also play a pivotal role in the pathogenesis of autoimmune diseases by initiating and perpetuating various cellular and humoral autoimmune processes.     

Selective reduction of natural killer T cells in the bone marrow of aplastic anaemia

T cell-mediated suppression of haematopoiesis is believed to play an important role in the pathophysiology of aplastic anaemia (AA) and in the pancytopenia of some myelodysplastic syndromes (MDS). Natural-killer T (NKT) cells belong to a unique lymphocyte subset that expresses an invariant T-cell receptor (TCR), consisting of Valpha24JalphaQ, and common NK cell surface markers. NKT cells have been hypothesized to play a role in immune regulation, and many human autoimmune conditions are associated with NKT cell deficiency. Here we investigate the role of NKT cells in AA and MDS patients. Flow cytometry demonstrated that NKT cells, unlike other T-lymphocyte subpopulations, were disproportionally decreased in AA and MDS marrow. When we compared variability within the CDR3 region of Valpha24 in CD4-CD8- T cells derived from AA and healthy individuals, the CDR3 size of Valpha24 cells showed a polyclonal distribution in AA patients, while in control subjects a typical oligoclonal or monoclonal pattern was found. Southern blot and sequence analysis of Valpha24 polymerase chain reaction products revealed that the NKT cell-specific JalphaQ region was predominant in control subjects, whereas it was not, or only very weakly, detected in AA and MDS patients. These results show that NKT cells are profoundly decreased in AA and MDS, and their deficiency may, as in other human autoimmune diseases, play a role in the local immune dysregulation in AA and MDS.     

Valpha24+ natural killer T-cell responses against T-acute lymphoblastic leukaemia cells: implications for immunotherapy

Human Valpha24+ natural killer T (NKT) cells correspond to mouse Valpha14+ NKT cells, both cell types use an invariant T-cell receptor-alpha chain and are activated by glycolipids in a CD1d-dependent manner. Mouse Valpha14+ NKT cells have been reported to have an antitumour effect in vivo. Human Valpha24+ NKT cells can kill a proportion of tumour cells in a CD1d-dependent manner in vitro. We report here that many human leukaemic T-cell lines express CD1d and can be directly killed by Valpha24+ NKT cells. This killing activity was enhanced in the presence of alpha-galactosylceramide (alpha-GalCer), a ligand of Valpha24+ NKT cells. Moreover, primary leukaemic T cells from five of eight T-cell acute lymphoblastic leukaemia (T-ALL) patients expressed CD1d and were good targets of Valpha24+ NKT cells. This cytotoxicity was increased in the presence of alpha-GalCer. Our results suggest that T-ALL is a good candidate for Valpha24+ NKT-cell-based immuno-cell therapy.     

Innate immune system plays a critical role in determining the progression and severity of acetaminophen hepatotoxicity

BACKGROUND & AIMS: Inflammatory mediators released by nonparenchymal inflammatory cells in the liver have been implicated in the progression of acetaminophen (APAP) hepatotoxicity. Among hepatic nonparenchymal inflammatory cells, we examined the role of the abundant natural killer (NK) cells and NK cells with T-cell receptors (NKT cells) in APAP-induced liver injury. METHODS: C57BL/6 mice were administered a toxic dose of APAP intraperitoneally to cause liver injury with or without depletion of NK and NKT cells by anti-NK1.1 monoclonal antibody (MAb). Serum alanine transaminase (ALT) levels, liver histology, hepatic leukocyte accumulation, and cytokine/chemokine expression were assessed. RESULTS: Compared with APAP-treated control mice, depletion of both NK and NKT cells by anti-NK1.1 significantly protected mice from APAP-induced liver injury, as evidenced by decreased serum ALT level, improved survival of mice, decreased hepatic necrosis, inhibition of messenger RNA (mRNA) expression for interferon-gamma (IFN-gamma), Fas ligand (FasL), and chemokines including KC (Keratinocyte-derived chemokine); MIP-1 alpha (macrophage inflammatory protein-1 alpha); MCP-1 (monocyte chemoattractant protein-1); IP-10 (interferon-inducible protein); Mig (monokine induced by IFN-gamma) and decreased neutrophil accumulation in the liver. Hepatic NK and NKT cells were identified as the major source of IFN-gamma by intracellular cytokine staining. APAP induced much less liver injury in Fas-deficient (lpr) and FasL-deficient (gld) mice compared with that in wild-type mice. CONCLUSIONS: NK and NKT cells play a critical role in the progression of APAP-induced liver injury by secreting IFN-gamma, modulating chemokine production and accumulation of neutrophils, and up-regulating FasL expression in the liver, all of which may promote the inflammatory response of liver innate immune system, thus contributing to the severity and progression of liver injury downstream of the metabolism of APAP and depletion of reduced glutathione (GSH) in hepatocytes.     

Ex‐vivo analysis of human Natural Killer T cells demonstrates heterogeneity between tissues and within established CD4+ and CD4− subsets

Our understanding of human type 1 natural killer T (NKT) cells has been heavily dependent on studies of cells from peripheral blood. These have identified two functionally distinct subsets defined by expression of CD4, although it is widely believed that this underestimates the true number of subsets. Two recent studies supporting this view have provided more detail about diversity of the human NKT cells, but relied on analysis of NKT cells from human blood that had been expanded in vitro prior to analysis. In this study we extend those findings by assessing the heterogeneity of CD4⁺ and CD4⁻ human NKT cell subsets from peripheral blood, cord blood, thymus and spleen without prior expansion ex vivo, and identifying for the first time cytokines expressed by human NKT cells from spleen and thymus. Our comparative analysis reveals highly heterogeneous expression of surface antigens by CD4⁺ and CD4⁻ NKT cell subsets and identifies several antigens whose differential expression correlates with the cytokine response. Collectively, our findings reveal that the common classification of NKT cells into CD4⁺ and CD4⁻ subsets fails to reflect the diversity of this lineage, and that more studies are needed to establish the functional significance of the antigen expression patterns and tissue residency of human NKT cells.     

NKT Cells at the Maternal-Fetal Interface

Establishment of the maternal-fetal interface is characterized by the influx of maternal NK cells, macrophages, and T cells into the decidua. Although a great deal has been learned about the function of NK cells in the decidua, comparatively little is known of decidual T cell function. NKT cells are an unusual T cell subset capable of producing both Th1-like and Th2-like cytokines. Unlike conventional αβ T cells that recognize peptides in the context of MHC molecules, NKT cells recognize glycolipids presented by the MHC class I-like molecule, CD1d. Recent reports have demonstrated that NKT cells and CD1d are present at the maternal-fetal interface. Moreover, activation of NKT cells can have dramatic effects on pregnancy. In this article, we will review basic aspects of NKT cell biology and summarize the recent literature on NKT cells at the maternal-fetal interface.