Effect of garlic consumption on the argyrophilic nucleolar organiser regions (AgNORs) in splenocytes and thymocytes of rats

The number and size of nucleolar organiser regions (NORs) are related to cell proliferation. To test the hypothesis that lymphocyte proliferation is associated with garlic consumption, 17 6-week-old male Wistar rats were separated into two groups. For 30 days eight rats were given garlic solution by gavage while the remaining nine animals received distilled water. Silver staining of NORs was performed on the fixed tissues of spleens and thymuses. The nuclear area (NA), nuclear length (NL), total AgNORs area (TAA), total AgNORs length (TAL) and total AgNORs number (TAN) of 100 analyzable nuclei of lymphocytes from each tissue were recorded. In spite of a decline in the average NA and NL of thymocytes from garlic-treated rats (p<0.001), TAA and TAL increased significantly (p<0.001) in the splenocytes and thymocytes of this group. In conclusion, garlic may enhance the lymphocyte proliferation in these two important organs from the rat immune system.     

Review of lithium effects on immune cells

Abstract

One of the remarkable discoveries in the field of psychopharmacology from late 1940s is Lithium (Li) that reminds of old but still gold. It continues to be a distinctive mood stabilizer that matches various standards recommended for mood stabilizers. Apart from this Li is also known to affect immune cell functions. Lithium response and regulations of different immune cells in bipolar patients, related immune disorders are not well defined. Here, we provide an overview of literature with regard to Li's effects on different immune cells. However, the use of Li is currently limited to bipolar disorders and there is no empirical evidence for immune cell disorders. The objective of this article is to provide the evaluations of Li responses towards the different immune cells based on the existing studies. Further, more studies are needed to understand the mechanistic basis and heterogeneous responses of Li's effect in bipolar, also unravel relative immune disorders.     

Mitochondrial and Nuclear Glucocorticoid-Sensitive Alkaline Proteases in Thymocytes

Glucocorticoid-sensitive alkaline proteases are localized in the nuclear and mitochondrial fractions of rat thymocytes. Dexamethasone load increased alkaline protease activity in the nuclear fraction and decreased or even eliminated it in the mitochondrial fraction. The inhibitory analysis showed that SH groups and disulfide bonds play a crucial role in the functioning of glucocorticoid-activated nuclear alkaline protease. Hence, this enzyme can be assigned to as cysteine proteases. Mitochondrial alkaline protease is a serine hydrolase, although it does not belong to the class of trypsin- or chymotrypsin-like enzymes. The role of alkaline proteases in apoptotic death of thymocytes is discussed.     

Coevolution of TCR-MHC interactions: conserved MHC tertiary structure is not sufficient for interactions with the TCR

The specificity for self-MHC that is necessary for T cell function is a consequence of intrathymic selection during which T cell antigen receptors (TCRs) expressed by immature thymocytes are tested for their affinity for self-peptide:self-MHC. The germ-line-encoded segments of the TCR, however, are believed to have an innate specificity for structural features of MHC molecules. We directly tested this hypothesis by generating a transgenic mouse system in which the protein HLA-DM is expressed at the surface of thymic cortical epithelial cells in the absence of classical MHC molecules. The specialized intracellular function of HLA-DM has removed this MHC class II-like protein from the evolutionary forces that have been hypothesized to shape TCR-MHC interactions. Our study shows that a structural mimic of MHC class II is not sufficient to appropriately interact with the TCRs expressed by developing thymocytes. This result emphasizes the unique complementarity of TCR-MHC interactions that are maintained by the evolutionary pressures dictated by positive selection.     

LAK细胞对肿瘤细胞杀伤作用的形态学研究

本文报道了用人胚胎中期脾脏和胸腺细胞经人重组ＩＬ－２激活而成的ＬＡＫ细胞与正常人淋巴细胞在形态、活性上的区别。并观察了在体外培养条件下ＬＡＫ细胞对肿瘤细胞的杀伤作用。     

Biological assays for interleukin 1 detection

Various biological assays are used for qualitative and quantitative measurements of interleukin 1 (IL-1) in supernatants from cell cultures. The purpose of the present study was to compare the specificity and variability of three cellular IL-1 bioassays: the PHA co-stimulatory human T lymphocyte proliferation assay, the PHA co-stimulatory murine thymocyte (THY) proliferation assay, and the 2-step NOB-1 conversion assay. Three different ways of IL-1 unit calculation, based on a semi-logarithmic plot, a double-logarithmic plot, or a probit-analysis plot were also compared. The T lymphocyte assay can be used only to demonstrate qualitative differences in IL-1-like activity, whereas the THY assay is excellent as a semi-quantitative assay, with a low intra-assay variability, but also with a low specificity. The NOB-1 assay is probably more specific with respect to IL-1 measurement, although, with a high intra-assay variance. The THY and the NOB-1 assays both have a high inter-assay variability, and measurement of samples from longitudinal clinical studies must be done in one and the same analysis if quantitative differences are to be illustrated. Probit analysis for unit calculation is recommended. To generate a consensus view as to assay performance, collaborative laboratory studies are needed.     

视黄酸对人胸腺细胞成熟分化影响及其作用机制

目的:研究视黄酸调节胸腺细胞发育的作用及其机制。方法:采用体外胸腺组织培养体系,在培养体系中加入视黄酸或视黄酸受体拮抗剂。在培养的不同时间收集胸腺细胞,用荧光标记的抗CD3、CD4、CD8抗体染色,并进行流式细胞仪分析,观察胸腺细胞表面标志随成熟分化的变化。胸腺细胞抽提的RNA采用实时定量PCR法检测视黄酸受体α(RARα) mRNA的表达。结果:体外胸腺组织培养体系能支持胸腺细胞的发育成熟。在培养24 h促进未成熟的CD4+CD8+胸腺细胞向CD4+成熟细胞分化发育作用明显,并且该作用可被RARα特异性拮抗剂Ro41-5253所拮抗。视黄酸也能显著抑制CD4+CD8+胸腺细胞向CD8+细胞分化,该作用也在培养24 h出现。实时定量PCR显示,视黄酸能促进RARα mRNA表达,并且 RARαmRNA表达水平与CD4+CD8+胸腺细胞百分数之间存在正相关,与CD8+胸腺细胞百分数之间存在负相关。结论:视黄酸可能通过影响其受体RARα表达而影响胸腺细胞的成熟分化。     

CD28 in thymocyte development and peripheral T cell activation in mice exposed to suspended particulate matter

The CD28:B7 signaling pathway is very important for the activity of mature peripheral T lymphocytes and thymocyte development. The proper development of thymocytes into mature single positive CD4⁺and CD8⁺ T cells is crucial for almost all immune functions. In naturally occurring conditions, T cells maturation in the thymus is influenced by environmental agents. The expression of CD28 and the distribution of CD28^low/high thymocytes have been examined at various stages of thymocyte development in BALB/c mice exposed to air-suspended particulate matter (ASM). Acute exposure to ASM resulted in the decrease of CD28 expression in the total thymocyte population. The increase of the percentage of CD28^low and the decrease of CD28^high thymocytes were observed, which may account for the acceleration of thymocyte development under the conditions of elevated risk resulting from the exposure of animals to environmental xenobiotics. ASM exposure resulted in the increase of the level of proliferation of lymph node T cells induced by anti-CD3 and anti-CD28 monoclonal antibodies activation despite normal expression of CD28 molecule. In contrast, the level of proliferation of spleen T cells was lowered or normal dependently of the concentration of stimuli used for activation. Results of these studies demonstrate that acute exposure of mice to ASM can result in the progression of two contrasting processes in the immune system: upregulation of thymocyte development, which contributes to the maintenance of peripheral T cell pool, and over-activation of lymph node lymphocytes, which may lead to uncontrolled immunostimulation.