Type I interferon production elicits differential CD4+ T-cell responses in mice infected with Plasmodium berghei ANKA and P. chabaudi.

Plasmodium parasites that infect humans are highly polymorphic, and induce various infections ranging from an asymptomatic state to life-threatening diseases. However, how the differences between the parasites affect host immune responses during blood-stage infection remains largely unknown. We investigated the CD4+ T-cell immune responses in mice infected with P. berghei ANKA (PbA) or P. chabaudi chabaudi AS (Pcc) using PbT-II cells, which recognize a common epitope of these parasites. In the acute phase of infection, CD4+ T-cell responses in PbA-infected mice showed a lower involvement of Th1 cells and a lower proportion of Ly6Clo effector CD4+ T cells than those in Pcc-infected mice. Transcriptome analysis of PbT-II cells indicated that type I interferon (IFN)-regulated genes were expressed at higher levels in both Th1- and Tfh-type PbT-II cells from PbA-infected mice than those from Pcc-infected mice. Moreover, IFN-α levels were considerably higher in PbA-infected mice than in Pcc-infected mice. Inhibition of type I IFN signaling increased PbT-II and partially reversed the Th1 over Tfh bias of the PbT-II cells in both PbA- and Pcc-infected mice. In the memory phase, PbT-II cells in PbA-primed mice maintained higher numbers and exhibited a better recall response to the antigen. However, recall responses were not significantly different between the infection groups after re-challenge with PbA, suggesting the effect of the inflammatory environment by the infection. These observations suggest that the differences in Plasmodium-specific CD4+ T-cell responses between PbA- and Pcc-infected mice were associated with the difference in type I IFN production during the early phase of the infection.

CD49d marks Th1 and Tfh-like antigen-specific CD4+ T cells during Plasmodium chabaudi infection.

Upon activation, specific CD4+ T cells up-regulate the expression of CD11a and CD49d, surrogate markers of pathogen-specific CD4+ T cells. However, using T-cell receptor transgenic mice specific for a Plasmodium antigen, termed PbT-II, we found that activated CD4+ T cells develop not only to CD11ahiCD49dhi cells, but also to CD11ahiCD49dlo cells during acute Plasmodium infection. CD49dhi PbT-II cells, localized in the red pulp of spleens, expressed transcription factor T-bet and produced IFN-γ, indicating that they were type 1 helper T (Th1)-type cells. In contrast, CD49dlo PbT-II cells resided in the white pulp/marginal zones and were a heterogeneous population, with approximately half of them expressing CXCR5 and a third expressing Bcl-6, a master regulator of follicular helper T (Tfh) cells. In adoptive transfer experiments, both CD49dhi and CD49dlo PbT-II cells differentiated into CD49dhi Th1-type cells after stimulation with antigen-pulsed dendritic cells, while CD49dhi and CD49dlo phenotypes were generally maintained in mice infected with Plasmodium chabaudi. These results suggest that CD49d is expressed on Th1-type Plasmodium-specific CD4+ T cells, which are localized in the red pulp of the spleen, and can be used as a marker of antigen-specific Th1 CD4+ T cells, rather than that of all pathogen-specific CD4+ T cells.

Physical Activity Attenuates the Obesity-Induced Dysregulated Expression of Brown Adipokines in Murine Interscapular Brown Adipose Tissue.

In recent years, brown adipose tissue (BAT), which has a high heat-producing capacity, has been confirmed to exist even in adults, and it has become a focal point for the prevention and the improvement of obesity and lifestyle-related diseases. However, the influences of obesity and physical activity (PA) on the fluid factors secreted from BAT (brown adipokines) are not well understood. In this study, therefore, we focused on brown adipokines and investigated the effects of obesity and PA. The abnormal expressions of gene fluid factors such as galectin-3 (Lgals3) and Lgals3 binding protein (Lgals3bp), whose proteins are secreted from HB2 brown adipocytes, were observed in the interscapular BAT of obese mice fed a high-fat diet for 4 months. PA attenuated the abnormalities in the expressions of these genes. Furthermore, although the gene expressions of factors related to brown adipocyte differentiation such as peroxisome proliferator-activated receptor gamma coactivator 1-α were also down-regulated in the BAT of the obese mice, PA suppressed the down-regulation of these factors. On the other hand, lipogenesis was increased more in HB2 cells overexpressing Lgals3 compared with that in control cells, and the overexpression of Lgals3bp decreased the mitochondrial mass. These results indicate that PA attenuates the obesity-induced dysregulated expression of brown adipokines and suggests that Lgals3 and Lgals3bp are involved in brown adipocyte differentiation.

Lantibiotics Produced by Oral Inhabitants as a Trigger for Dysbiosis of Human Intestinal Microbiota.

Lantibiotics are a type of bacteriocin produced by Gram-positive bacteria and have a wide spectrum of Gram-positive antimicrobial activity. In this study, we determined that Mutacin I/III and Smb (a dipeptide lantibiotic), which are mainly produced by the widespread cariogenic bacterium Streptococcus mutans, have strong antimicrobial activities against many of the Gram-positive bacteria which constitute the intestinal microbiota. These lantibiotics also demonstrate resistance to acid and temperature. Based on these features, we predicted that lantibiotics may be able to persist into the intestinal tract maintaining a strong antimicrobial activity, affecting the intestinal microbiota. Saliva and fecal samples from 69 subjects were collected to test this hypothesis and the presence of lantibiotics and the composition of the intestinal microbiota were examined. We demonstrate that subjects possessing lantibiotic-producing bacteria in their oral cavity exhibited a tendency of decreased species richness and have significantly reduced abundance of the phylum Firmicutes in their intestinal microbiota. Similar results were obtained in the fecal microbiota of mice fed with S. mutans culture supernatant containing the lantibiotic bacteriocin Mutacin I. These results showed that lantibiotic bacteriocins produced in the oral cavity perturb the intestinal microbiota and suggest that oral bacteria may be one of the causative factors of intestinal microbiota dysbiosis.

[The Risk Factors of Cancer Chemotherapy in Elderly Patients].

The aging rate in Japan is the highest in the world, and it is entering a very aging society that has never happened before. The first cause of death is a malignant neoplasm, and opportunities of the treatment for elderly cancer patients are rapidly increasing. The elderly have increased chronic diseases and complications with aging, and the adverse event in medication therapy also increases. Also, the form of medical provision is diversified, home medical care and nursing care are recommended. Therefore, it is important to appreciate the various aspects including psychophysiological, living, social aspects in addition to changes in physical function caused by aging and appropriately evaluate them, for selecting treatment methods in elderly cancer patients. Geriatric assessment(GA)is recommended for this evaluation, and it is expected to contribute to improvement of treatment outcome and quality of life(QOL). In this article, we will outline the role of aged general comprehensive functional evaluation in elderly cancer treatment and the problems of chemotherapy in the elderly.

Marginally excessive iron loading transiently blocks mucosal iron uptake in iron-deficient rats.

Regular "mucosal block" is characterized by decreased uptake of a normal iron load 3-72 h after the administration of excess iron (generally 10 mg) to iron-deficient animals. We found that short-acting mucosal block could be induced by much lower iron concentration and much shorter induction time than previously reported, without affecting levels of gene expression. A rapid endocytic mechanism was reported to decrease intestinal iron absorption after a high iron load, but the activating iron load and the time to decreased absorption were undetermined. We assessed the effects of 30-2,000 µg iron load on iron uptake in the duodenal loop of iron-deficient and iron-sufficient rats under anesthesia. One hour later, mucosal cellular iron uptake in iron-deficient rats administered 30 µg iron was 76.1%, decreasing 25% to 50.7% in rats administered 2,000 µg iron. In contrast, iron uptake by iron-sufficient rats was 63% (range 60.3-65.5%) regardless of iron load. Duodenal mucosal iron concentration was significantly lower in iron-deficient than in iron-sufficient rats. Iron levels in portal blood were consistently higher in iron-deficient rats regardless of iron load, in contrast to the decreased iron uptake on the luminal side. Iron loading blocked mucosal uptake of marginally excess iron (1,000 µg), with a greater effect at 15 min than at 30 min. The rapid induction of short-acting mucosal block only in iron-deficient rats suggests DMT1 internalization.

Differential impact of environmental factors on airborne live bacteria and inorganic particles in an underground walkway.

We previously reported that variations in the number and type of bacteria found in public spaces are influenced by environmental factors. However, based on field survey data alone, whether the dynamics of bacteria in the air change as a result of a single environmental factor or multiple factors working together remains unclear. To address this, mathematical modeling may be applied. We therefore conducted a reanalysis of the previously acquired data using principal component analysis (PCA) in conjunction with a generalized linear model (Glm2) and a statistical analysis of variance (ANOVA) test employing the χ2 distribution. The data used for the analysis were reused from a previous public environmental survey conducted at 8:00-20:00 on May 2, June 1, and July 5, 2016 (regular sampling) and at 5:50-7:50 and 20:15-24:15 on July 17, 2017 (baseline sampling) in the Sapporo underground walking space, a 520-meter-long underground walkway. The dataset consisted of 60 samples (22 samples for "bacterial flora"), including variables such as "temperature (T)," "humidity (H)," "atmospheric pressure (A)," "traffic pedestrians (TP)," "number of inorganic particles (Δ5: 1-5 µm)," "number of live airborne bacteria," and "bacterial flora." Our PCA with these environmental factors (T, H, A, and TP) revealed that the 60 samples could be categorized into four groups (G1 to G4), primarily based on variations in PC1 [Loadings: T(-0.62), H(-0.647), TP(0.399), A(0.196)] and PC2 [Loadings: A(-0.825), TP(0.501), H(0.209), T(-0.155)]. Notably, the number of inorganic particles significantly increased from G4 to G1, but the count of live bacteria was highest in G2, with no other clear pattern. Further analysis with Glm2 indicated that changes in inorganic particles could largely be explained by two variables (H/TP), while live bacteria levels were influenced by all explanatory variables (TP/A/H/T). ANOVA tests confirmed that inorganic particles and live bacteria were influenced by different factors. Moreover, there were minimal changes in bacterial flora observed among the groups (G1-G4). In conclusion, our findings suggest that the dynamics of live bacteria in the underground walkway differ from those of inorganic particles and are regulated in a complex manner by multiple environmental factors. This discovery may contribute to improving public health in urban settings.

C-X-C motif receptor 3A enhances proliferation and invasiveness of colorectal cancer cells, and is mediated by C-X-C motif ligand 10.

The chemokine CXCL10 and its receptor CXCR3 have been demonstrated to be implicated in cancer cell proliferation and metastasis. CXCR3 has three splice variants: CXCR3A, CXCR3B and CXCR3-alt. CXCR3A and B serve multiple roles in the growth and invasiveness of a number of cancer types. However, the roles of CXCR3 isoforms in colorectal cancer (CRC) cells remain unclear. In the current study, the effects of CXCL10 and CXCR3 isoforms on proliferation and invasion of CRC cells was examined. Proliferation and invasiveness of the CRC cell line HCT116, which were transfected with CXCR3A or CXCR3B in the presence of CXCL10, were evaluated in vitro using MTT, scratch wound healing and transwell assays. MTT assay indicated that regardless of the presence or absence of CXCL10, the proliferative ability of CXCR3A-transfected HCT116 cells was enhanced compared with blank and mock cells. Scratch wound healing and transwell assays indicated that invasiveness of CXCR3A-transfected cells was greater compared with blank and mock cells. However, HCT116 cells transfected with CXCR3B did not exhibit changes in their proliferative or invasive ability. mRNA expression of MMP9, which is associated with signaling downstream of the CXCL10/CXCR3A pathway, was increased 4-fold in CXCR3A-transfected HCT116 cells compared with control cells. The results of the present study indicated that CXCL10-enhanced proliferation and invasiveness of the CRC cell line HCT116 was likely mediated by CXCR3A, but not by CXCR3B.

Influence of Intestinal Indigenous Microbiota on Intrafamilial Infection by Helicobacter pylori in Japan.

Helicobacter pylori is a causative pathogen of chronic gastritis, gastric ulcer disease, and gastric cancer. Humans are known to be a natural host for H. pylori and tend to acquire the pathogen before the age of 5 years. The infection may then persist lifelong if eradication therapy is not applied. One of the modes of transmission of H. pylori is between family members, and therefore, the presence of infected family members is an important risk factor in children. However, other environmental factors have not been fully analyzed. The present study was performed to clarify whether and to what extent intestinal microbiota affect H. pylori intrafamilial infection. The fecal specimens from H. pylori-infected infants and H. pylori-infected and non-infected family members were collected in cohort studies conducted by Sasayama City, Hyogo Prefecture from 2010 to 2013. In total, 18 fecal DNA from 5 families were analyzed. Samples were amplified using 16S rRNA universal primers, and the amplicons were sequenced using the Ion PGM system. Principal-coordinate analysis demonstrated that there was no difference in intestinal microbiota between H. pylori-positive and H. pylori-negative groups. In intrafamilial comparison tests, the Manhattan distance of intestinal microbiota between the H. pylori-infected infant proband and H. pylori-negative mother was nearest in the family with low intestinal microbial diversity. However, in the family with the highest intestinal microbial diversity, the nearest Manhattan distance was shown between the H. pylori-infected infant proband and H. pylori-infected mother. The results in this study showed that the composition of the intestinal microbiota was very similar between members of the same family, and as such, colonization with organisms highly similar to the infected parent(s) may be a risk factor for H. pylori infection in children.

Walker occupancy has an impact on changing airborne bacterial communities in an underground pedestrian space, as small-dust particles increased with raising both temperature and humidity.

Although human occupancy is a source of airborne bacteria, the role of walkers on bacterial communities in built environments is poorly understood. Therefore, we visualized the impact of walker occupancy combined with other factors (temperature, humidity, atmospheric pressure, dust particles) on airborne bacterial features in the Sapporo underground pedestrian space in Sapporo, Japan. Air samples (n = 18; 4,800L/each sample) were collected at 8:00 h to 20:00 h on 3 days (regular sampling) and at early morning / late night (5:50 h to 7:50 h / 22:15 h to 24:45 h) on a day (baseline sampling), and the number of CFUs (colony forming units) OTUs (operational taxonomic units) and other factors were determined. The results revealed that temperature, humidity, and atmospheric pressure changed with weather. The number of walkers increased greatly in the morning and evening on each regular sampling day, although total walker numbers did not differ significantly among regular sampling days. A slight increase in small dust particles (0.3-0.5µm) was observed on the days with higher temperature regardless of regular or baseline sampling. At the period on regular sampling, CFU levels varied irregularly among days, and the OTUs of 22-phylum types were observed, with the majority being from Firmicutes or Proteobacteria (γ-), including Staphylococcus sp. derived from human individuals. The data obtained from regular samplings reveled that although no direct interaction of walker occupancy and airborne CFU and OTU features was observed upon Pearson's correlation analysis, cluster analysis indicated an obvious lineage consisting of walker occupancy, CFU numbers, OTU types, small dust particles, and seasonal factors (including temperature and humidity). Meanwhile, at the period on baseline sampling both walker and CFU numbers were similarly minimal. Taken together, the results revealed a positive correlation of walker occupancy with airborne bacteria that increased with increases in temperature and humidity in the presence of airborne small particles. Moreover, the results indicated that small dust particles at high temperature and humidity may be a crucial factor responsible for stabilizing the bacteria released from walkers in built environments. The findings presented herein advance our knowledge and understanding of the relationship between humans and bacterial communities in built environments, and will help improve public health in urban communities.

Microarray Analysis of Gene Expression at the Tumor Front of Colon Cancer.

Budding or the presence poorly differentiated clusters at the boundary of cancer tissue is a pathologically important finding and serves as a prognostic factor in colorectal cancer. However, few studies have examined the cancer tissue boundary in clinical samples. The purpose of the present study was to examine gene expression at the tumor front of colon cancer in surgically resected samples. Cancer tissues were obtained by laser microdissection of 20 surgically resected specimens. Genes with significantly different microarray signals between the tumor front and the tumor center were identified. Among genes showing significant up-regulation at the tumor front were six chemokines [chemokine c-c motif ligand (CCL)2 and -18, chemokine (C-X-C motif) ligand (CXCL)9-11, and interleukin 8 (IL8)], and two apoptosis-related molecules [ubiquitin D (UBD) and baculoviral iap repeat-containing 3 (BIRC3)]. Expression of laminin gamma 2 (LAMC2), matrix metallopeptidase 7 (MMP7) and epithelial-mesenchymal transition (EMT)-related molecules were elevated in the tumor front, but their fold changes were smaller than those of the aforementioned genes. These results suggest that chemokines, in addition to EMT-related molecules, may play important roles in invasion of colon cancer.

Whole-Genome Sequence of Mycobacterium kyorinense.

We report here the first draft genome sequence of Mycobacterium kyorinense, which was described in 2009 and exhibits significant pathogenicity to humans.