Dextran sulphate enhancement of lipopolysaccharide-induced tumour necrosis factor-α production by murine peritoneal macrophages: Correlation with macrophage blockade

Abstract Proteose peptone-induced murine peritoneal macrophages (Mø) were preincubated with 100–800 μg/ml of dextran sulphate (DS) 500 ( M _r 500 000) or DS1000 ( M _r 1 000 000). After 2–24 h of the preincubation, the Mø were stimulated with 1 μg/ml of lipopolysaccharide (LPS) in vitro for 18 h in DS-free culture medium. The culture supernatants were then collected for TNF assay. The LPS-induced TNF activity of Mø supernatant preincubated with DS500 or DS1000 for 6 h was enhanced by up to about ten-fold compared with those preincubated without DS. This enhancing effect was not observed when Mø were preincubated with 100–800 μg/ml of low molecular weight DS5 ( M _r 5000) or neutral dextran (Dex) 500 ( M _r 500 000). The enhancement of LPS-induced TNF-α production from Mø was observed after 2 or 4 h of incubation with DS1000 or DS500, respectively. The phagocytic activity of Mø was determined in vitro by the ingestion index and phagocytic capacity using Saccharomyces cerevisiae . Treatment with DS500 or DS1000 significantly suppressed the phagocytic activity from 2 h after the incubation, but this suppression was not observed in Mø incubated with DS5 or Dex500. Our experiments indicate that DS500 and DS1000 act directly on Mø and enhance LPS-induced TNF-α production from Mø, and that the enhancement is closely related to the suppression of Mø phagocytic function.     

胞内致病菌入侵宿主细胞分子机理研究进展

胞内致病菌,指能够侵入宿主细胞且在宿主细胞内存活并繁殖的病原菌。其入侵宿主细胞的过程主要涉及细菌黏附宿主细胞、侵袭、细菌在细胞内存活以及引起宿主细胞损伤等。先前的研究表明大多数胞内致病菌是通过吞噬细胞被动地摄取,而随着分子生物学和免疫学的发展,越来越多的胞内致病菌被证明能主动入侵到宿主细胞体内,并进化出各种调控宿主细胞信号通路的方式。本文讨论了胞内致病菌在入侵宿主细胞时各阶段的共同的分子机制以及常见的胞内致病菌所采取的入侵策略,并对近年来国内外主要相关研究进展做一总结。     

Tumour-cell-induced production of tumour necrosis factor by monocytes of gastric cancer patients receiving BCG immunotherapy

Summary Human peripheral blood monocytes cocultured with tumour cells were used as an in vitro model of in situ interactions between tumour-infiltrating macrophages and the tumour. Tumour cells stimulated de novo expression of the human tumour necrosis factor (TNF) gene in monocytes and caused the release of TNF into the culture supernatant. A group of 14 patients with stage IVA gastric cancer receiving adjuvant chemotherapy (5-FU, Adriamycin, mitomycin C: FAM) or immunochemotherapy (BCG+FAM) was investigated for the ability of monocytes to produce TNF in vitro upon stimulation with tumour cells or purified protein derivative of tuberculin (PPD). Patients were followed at biweekly intervals, i.e. before each instillation of BCG epicutaneously over a period of 10 weeks. It was found that monocytes of some patients receiving BCG at the end of the observation period had an enhanced ability to produce TNF following stimulation with tumour cells. In contrast, such production was not substantially altered during the study period in patients on chemotherapy. PPD-induced TNF production was much weaker and was not significantly changed during this observation time. We infer that BCG immunotherapy may induce the subtle changes in some cancer patients that lead to an increased interaction between monocytes and tumour cells and result in enhanced production of cytokine(s) with antitumour properties.     

In vitro expansion and analysis of T lymphocyte microcultures obtained from the vaccination sites of cancer patients undergoing active specific immunization with autologous Newcastle-disease-virus-modified tumour cells

In order to understand further the effects of Newcastle-disease-virus(NDV)-modified tumour vaccines we investigated the feasibility of isolating lymphocytes from the site of injection of patients undergoing postoperative active specific immunization (ASI) with autologous NDV-modified tumour cells. Delayed-type-hypersensitivity(DTH)-like reactions from five cancer patients were surgically removed, minced and the tissue particles were digested with collagenase and DNase. Lymphoid cells recovered were expanded in a highly efficient limiting-dilution analysis system optimized for T cell growth [Moretta et al. (1983) J Exp Med 157: 743] and lymphocyte microcultures (clonal probability >0.8) could be grown for up to 1 year. Analysis of the microcultures for phenotype and function showed that the majority were positive for CD4 (92%) and TCR (96%). Concanavalin-A-induced production of interleukin-2 (IL-2), IL-6, interferon and tumour necrosis factor was detected in more than 70% of the microcultures. Lectin-dependent cytotoxicity was only very rarely observed. The general characteristics of the microcultures obtained support the notion of a DTH-like reaction taking place at the site of tumour cell challenge. The possibility of in vitro expansion and cultivation of T lymphocytes from ASI vaccination sites should help to elucidate further the role of these cells in active specific immunization against autologous tumour cells.This study was supported by Dr.-Mildred-Scheel-Stiftung and the Tumorzentrum Heidelberg     

Phenology and thallus size in a non-native population of Gracilaria vermiculophylla

Phenology, or seasonal variation in life cycle events, is poorly described for many macroalgal species. We describe the phenology of a non-native population of Gracilaria vermiculophylla whose thalli are free-living or anchored by decorating polychaetes to tube caps. At a site in South Carolina, USA, we sampled 100 thalli approximately every month from January 2014 to January 2015. We assessed the reproductive state and measured thallus size based on wet weight, thallus length, and thallus surface area from herbarium mounts. Because life cycle stage cannot be assigned using morphology, we implemented a PCR assay to determine the life cycle stage—tetrasporophyte, female gametophyte, or male gametophyte—of each thallus. Tetrasporophytes dominated throughout the year, making up 81%–100% of thalli sampled per month. Reproductive tetrasporophytes varied between 0% and 65% of monthly samples and were most common in warm summer months (July through September) when thalli also tended to be larger. The vast majority of the reproductive thalli were worm-anchored and not fixed to hard substratum via a holdfast. Thus, free-living thalli can be reproductive and potentially seed new non-native populations. Given G. vermiculophylla reproduction seems tied closely to temperature, our work suggests phenology may change with climate-related changes in seawater temperatures. We also highlight the importance of understanding the natural history of macroalgae to better understand the consequence of range expansions on population dynamics.     

Invasion promoter versus invasion suppressor molecules: the paradigm of E-cadherin

Conclusion Metastasis determines cancer malignancy. Neoplastic cells metastasize through a multistep process of invasion. At each step, these cells create a dynamic micro-ecosystem in which the elements of the host are considered to paricipate actively invasion. Within such micro-ecosystems, invasion is believed to be governed by a balance between the activation of promoter (i-minus) and suppressor (i-plus) genes. Products of such genes regulate the expression of the invasive (I-plus) and the nonivasive (I-minus) phenotypes. Experimentsin vitro andin vivo, as well as observations on human cancers have put forward the cell-cell adhesion molecule E-cadherin (L-CAM; uvomorulin) as a regulator of epithelial organization and an invasion suppressor.     

Pathogen invasion and host extinction in lattice structured populations

We examined the propagation of an infectious disease and the eventual extinction of the host population in a lattice-structured population. Both the host colonization and pathogen transmission processes are assumed to be restricted to act between the nearest neighbor sites. The model is analyzed by an improved version of pair approximation (IPA). Pair approximation is a technique to trace the dynamics of the number of nearest neighbor pairs having particular states, and IPA takes account of the clustering property of lattice models more precisely. The results are checked by computer simulations. The analysis shows: (i) in a one-dimensional lattice population, a pathogen cannot invade a host population no matter how large is the transmission rate; (ii) in a two-dimensional lattice population, pathogens will drive the host to extinction if the transmission rate is larger than a threshold. These results indicate that spatially structured population models may give qualitatively different results from conventional population models, such as Lotka-Volterra ones, without spatial structure.     

Manipulation of cellular interactions with biomaterials toward a therapeutic outcome: A perspective

Manipulation of the Wound healing process and the manner in which tissues interact with inertbiomaterials were both made possible with the discovery of arginine-glucine (RGD) acid as a major cell recognition signal in the extracellular matrix. Whether promoting cell adhesion can be rationally designed to incorporate both stability and integrin specificity. Synthetic peptides containing this sequence have been linked to biodegradable biopolumers and introduced for the enhancement of dermal and corneal wound healing. By accelerating the healing reaction using RGD-containing peptides, the quality of regenerted tissue seems to be improved, the extent of fibrosis retricted, and the risk of microbial infection may be reduced. Controlling the degree of fibrosis that often accmmpanies the healing of wounds and the reaction of tissue to foreign materials can also be achieved by natural antagonists of fibrogenic activity of TGF-beta animal models of kidney fobrosis. There advances in the biotechnology of wound healing and tissue regeneration eventually will have an overal impact on the quality of health care.     

Protection by dexamethasone from a lethal infection with Listeria monocytogenes in mice

Abstract The effects of dexamethasone (DEX) on a lethal infection with Listeria monocytogenes were studied in mice. Mice were completely protected against the lethal infection when treated with 3.3 mg per kg of DEX. The effect was observed only when DEX was injected before infection. The control mice died from day 3 to day 5 of infection, whereas DEX-treated mice could eliminate L. monocytogenes cells from the organs by day 11 of infection. High titres of endogenous tumour necrosis factor (TNF), interleukin-6 (IL-6) and gamma interferon (IFN-γ) were induced in the bloodstreams and organs of the drug-free mice. DEX suppressed IL-6 production, but augmented TNF and IFN-γ production within 24 h of infection, whereas production of all three endogenous cytokines was suppressed in the DEX-treated mice on day 3 of infection when the control mice began to die. These results suggest that DEX shows a protective effect on a lethal infection with L. monocytogenes in mice and that regulation of production of endogenous cytokines might be involved in the effect of DEX.     

超声弹性成像联合血清TSH、TK1、LMTK3对甲状腺乳头状癌的诊断价值及与肿瘤侵袭和增殖的关系研究

摘要 目的：探讨超声弹性成像（UE）联合血清促甲状腺激素（TSH）、胸苷激酶1（TK1）、Lemur-酪氨酸激酶3（LMTK3）对甲状腺乳头状癌（PTC）的诊断价值及与肿瘤侵袭和增殖的关系。方法：选取2020年1月-2022年12月海军军医大学第二附属医院收治的91例PTC患者作为观察组。另选取本院同期90例甲状腺良性肿瘤患者作为对照组。对所有患者开展UE检查,对比两组UE参数,同时检测并对比两组血清TSH、TK1、LMTK3水平以及组织标本中侵袭基因、增殖基因的信使核糖核酸（mRNA）表达水平。Pearson法分析UE参数、血清TSH、TK1、LMTK3与侵袭基因、增殖基因mRNA表达水平的相关性。受试者工作特征（ROC）曲线分析UE联合血清TSH、TK1、LMTK3对PTC的诊断效能。结果：观察组超声弹性评分（ES）、弹性系数（SR）均高于对照组（均P＜0.05）。观察组血清TSH、TK1、LMTK3水平均高于对照组（均P＜0.05）。观察组去整合素-金属蛋白酶9（ADAM-9）、BCL6共抑制因子样蛋白1（BCORL1）、Xklp2靶蛋白（TPX2）及Twist1 mRNA表达水平均高于对照组（均P＜0.05）。Pearson法分析结果显示,ES、SR及血清TSH、TK1、LMTK3均和ADAM9、BCORL1、TPX2、Twist1 mRNA表达水平均呈正相关（均P＜0.05）。ES、SR及血清TSH、TK1、LMTK3联合检测对PTC诊断的灵敏度为91.52%,特异度为87.34%,曲线下面积（AUC）为0.894,联合诊断的效能均优于上述五项指标单独检测。结论：UE联合血清TSH、TK1、LMTK3对PTC具有较高的诊断价值。上述指标异常升高与PTC肿瘤侵袭、增殖有关。