A series of immune responses leading to the induction ofT cell IL-12/IL-18 responsiveness in patientswith relatively large tumor burdens

The induction of interleukin-12 (IL-12) responsiveness in T cells depends on T cell receptor (TCR) triggering, and is regarded as a parameter of recently TCR-sensitized T cells. Here, we investigated whether IL-12 responsiveness could be detected in freshly prepared T cells from tumor-bearing patients, and if so whether such patients exhibited additional immunological parameters related to IL-12 responsiveness. CD4(+) and CD8(+) T cell populations from an appreciable proportion of tumor-bearing patients exhibited high levels of IL-12 responsiveness as evaluated by IL-12-stimulated interferon-gamma (IFN-gamma) production. T cell populations with high IL-12 responsiveness were observed in the group of patients with moderate to large tumor mass or tumor metastases rather than in patients with small tumors. The frequency of such a T cell population was also lower in post-surgery tumor-free patients, showing the correlation between IL-12 responsiveness and the presence of a certain extent of tumor burden. More importantly, a higher incidence of IL-12 responsiveness was observed in tumor-bearing patients exhibiting detectable plasma IL-12 levels, and correlated with IL-18 responsiveness. T cell IL-12 and IL-18 responsiveness is induced by TCR triggering and subsequent IL-12 stimulation respectively. Furthermore, TCR-triggered T cells stimulate antigen-presenting cells (APC) to produce IL-12. Therefore, the present observations suggest that an immune response loop from TCR sensitization to the induction of IL-12/IL-18 responsiveness via IL-12 production operates in tumor-bearing patients, particularly in those with relatively large tumor burdens.     

Cutting edge: profile of chemokine receptor expression on human plasma cells accounts for their efficient recruitment to target tissues

We systematically examined the repertoire of chemokine receptors expressed by human plasma cells. Fresh bone marrow plasma cells and myeloma cells consistently expressed CXCR4, CXCR6, CCR10, and CCR3. Accordingly, plasma cells responded to their respective ligands in chemotaxis and very late Ag-4-dependent cell adhesion to fibronectin. Immobilized CXC chemokine ligand (CXCL)16, a novel transmembrane-type chemokine and CXCR6 ligand, also directly induced adhesion of plasma cells without requiring G(alpha i) signaling or divalent cations. Furthermore, we revealed consistent expression of CXCL12 (CXCR4 ligand), CXCL16 (CXCR6 ligand), and CC chemokine ligand 28 (CCR10 and CCR3 ligand) in tissues enriched with plasma cells including bone marrow, and constitutive expression of CXCL12, CXCL16, and CC chemokine ligand 28 by cultured human bone marrow stromal cells. Collectively, plasma cells are likely to be recruited to bone marrow and other target tissues via CXCR4, CXCR6, CCR10, and CCR3. CXCR6 may also contribute to tissue localization of plasma cells through its direct binding to membrane-anchored CXCL16.     

Intra- and inter-laboratory variation in the scoring of micronuclei and nucleoplasmic bridges in binucleated human lymphocytes. Results of an international slide-scoring exercise by the HUMN project

One of the objectives of the HUman MicroNucleus (HUMN) project is to identify the methodological variables that have an important impact on micronucleus (MN) or micronucleated (MNed) cell frequencies measured in human lymphocytes using the cytokinesis-block micronucleus assay. In a previous study we had shown that the scoring criteria used were likely to be an important variable. To determine the extent of residual variation when laboratories scored cells from the same cultures using the same set of standard scoring criteria, an inter-laboratory slide-scoring exercise was performed among 34 laboratories from 21 countries with a total of 51 slide scorers involved. The results of this study show that even under these optimized conditions there is a great variation in the MN frequency or MNed cell frequency obtained by individual laboratories and scorers. All laboratories ranked correctly the MNed cell frequency in cells from cultures that were unirradiated, or exposed to 1 or 2Gy of gamma rays. The study also estimated that the intra-scorer median coefficient of variation for duplicate MNed cell frequency scores is 29% for unexposed cultures and 14 and 11% for cells exposed to 1 and 2Gy, respectively. These values can be used as a standard for quality or acceptability of data in future studies. Using a Poisson regression model it was estimated that radiation dose explained 67% of the variance, while staining method, cell sample, laboratory, and covariance explained 0.6, 0.3, 6.5, and 25.6% of the variance, respectively, leaving only 3.1% of the variance unexplained. As part of this exercise, nucleoplasmic bridges were also estimated by the laboratories; however, inexperience in the use of this biomarker of chromosome rearrangement was reflected in the much greater heterogeneity in the data and the unexplained variation estimated by the Poisson model. The results of these studies indicate clearly that even after standardizing culture and scoring conditions it will be necessary to calibrate scorers and laboratories if MN, MNed cell and nucleoplasmic bridge frequencies are to be reliably compared among laboratories and among populations.     

Ras activation in T cells determines the development of antigen-induced airway hyperresponsiveness and eosinophilic inflammation

The central role for Th2 cells in the development of Ag-induced airway hyperresponsiveness and eosinophilic inflammation is well documented. We have reported a crucial role for TCR-induced activation of the Ras/extracellular signal-regulated kinase mitogen-activated protein kinase cascade in Th2 cell differentiation. Here, we show that the development of both OVA-induced airway hyperresponsiveness and eosinophilic airway inflammation in a mouse asthma model are attenuated in transgenic mice by the overexpression of enzymatically inactive Ras molecules in T cells. In addition, reduced levels of IL-5 production and eosinophilic inflammation induced by nematode infection (Nippostrongylus brasiliensis or Heligmosomoides polygyrus) were detected. Thus, the level of Ras activation in T cells appears to determine Th2-dependent eosinophilic inflammation and Ag-induced airway hyperresponsiveness.     

Molecular cloning of rat brain mitochondrial carrier protein-1 cDNA and its up-regulation during postnatal development

Brain mitochondrial carrier protein-1 (BMCP1), a new member of the mitochondrial uncoupling carrier, has been shown to be expressed predominantly in the brain of the mice and humans. We cloned rat BMCP1 cDNA and investigated its mRNA level during postnatal development and under various metabolic conditions. The nucleotide sequence of the cDNA revealed that rat BMCP1 protein was composed of 322 amino acid residues, and was 99 and 96% identical to the mouse and human proteins and 29, 33 and 35% identical to rat uncoupling protein (UCP) 1, UCP2 and UCP3, respectively. The molecular weight was predicted to be 36017 Da and the protein of this size was detectable when the cDNA was expressed in vitro. Using Northern blot analysis, the corresponding mRNA, approximately 1.8-kb in size, was found expressed predominantly in the cerebrum, cerebellum and hypothalamus. A unique developmental pattern was identified in the brain, where BMCP1 expression was low in their fetal life, but significantly elevated in the first postnatal week. Thereafter BMCP1 mRNA was maintained to be gradually increased. In 48-h fasted or insulin-induced hypoglycemic rats, BMCP1 mRNA expression in the hypothalamus slightly, but significantly, decreased compared with that in their appropriate controls. The present results indicate that BMCP1 may be involved in pathogenesis of mitochondrial dysfunction in neurons induced by aging or neurodegenerative disorders, and perhaps in energy balance in the brain.     

Relationships between Micro-Vascular and Iodine-Staining Patterns in the Vicinity of the Tumor Front of Superficial Esophageal Squamous Carcinoma

Objective

The aim of the present study was to clarify differences between micro-vascular and iodine-staining patterns in the vicinity of the tumor fronts of superficial esophageal squamous cell carcinomas (ESCCs).

Methods

Ten consecutive patients with ESCCs who were treated by endoscopic submucosal dissection (ESD) were enrolled. At the edge of the iodine-unstained area, we observed 183 sites in total using image-enhanced magnifying endoscopy. We classified the micro-vascular and iodine-staining patterns into three types: Type A, in which the line of vascular change matched the border of the iodine-unstained area; Type B, in which the border of the iodine-unstained area extended beyond the line of vascular change; Type C, in which the line of vascular change extended beyond the border of the iodine-unstained area. Then, by examining histopathological sections, we compared the diameter of intra-papillary capillary loops (IPCLs) in cancerous areas and normal squamous epithelium.

Results

We investigated 160 sites that the adequate quality of pictures were obtained. There was no case in which the line of vascular change completely matched the whole circumference of the border of an iodine-unstained area. Among the 160 sites, type A was recognized at 76 sites (47.5%), type B at 79 sites (49.4%), and type C at 5 sites (3.1%). Histological examination showed that the mean diameter of the IPCLs in normal squamous epithelium was 16.2±3.7μm, whereas that of IPCLs in cancerous lesions was 21.0±4.4μm.

Conclusions

The development of iodine-unstained areas tends to precede any changes in the vascularity of the esophageal surface epithelium.     

The YlmG protein has a conserved function related to the distribution of nucleoids in chloroplasts and cyanobacteria

Background  

Reminiscent of their free-living cyanobacterial ancestor, chloroplasts proliferate by division coupled with the partition of nucleoids (DNA-protein complexes). Division of the chloroplast envelope membrane is performed by constriction of the ring structures at the division site. During division, nucleoids also change their shape and are distributed essentially equally to the daughter chloroplasts. Although several components of the envelope division machinery have been identified and characterized, little is known about the molecular components/mechanisms underlying the change of the nucleoid structure.