ParA encoded on chromosome II of Deinococcus radiodurans binds to nucleoid and inhibits cell division in Escherichia coli

Bacterial genome segregation and cell division has been studied mostly in bacteria harbouring single circular chromosome and low-copy plasmids. Deinococcus radiodurans, a radiation-resistant bacterium, harbours multipartite genome system. Chromosome I encodes majority of the functions required for normal growth while other replicons encode mostly the proteins involved in secondary functions. Here, we report the characterization of putative P-loop ATPase (ParA2) encoded on chromosome II of D. radiodurans. Recombinant ParA2 was found to be a DNA-binding ATPase. E. coli cells expressing ParA2 showed cell division inhibition and mislocalization of FtsZ-YFP and those expressing ParA2-CFP showed multiple CFP foci formation on the nucleoid. Although, in trans expression of ParA2 failed to complement SlmA loss per se, it could induce unequal cell division in slmAminCDE double mutant. These results suggested that ParA2 is a nucleoid-binding protein, which could inhibits cell division in E. coli by affecting the correct localization of FtsZ and thereby cytokinesis. Helping slmAminCDE mutant to produce minicells, a phenotype associated with mutations in the ‘Min’ proteins, further indicated the possibility of ParA2 regulating cell division by bringing nucleoid compaction at the vicinity of septum growth.     

Oxysterols induce transition of monocytic cells to phenotypically mature dendritic cell-like cells

Dendritic cells (DCs) activate adaptive immune responses in atherosclerotic plaques; however, the origin of DCs is in question. We attempted to determine whether cholesterol or its oxide forms, which are detected in abundance in atheromatous lesions, could induce differentiation or transition of monocytic cells to DCs. Treatment of THP-1 cells with 27-hydroxycholesterol (27OH-Chol) and 7α-hydroxycholesterol (7αOH-Chol) resulted in an increase in the numbers of adherent cells, and, in contrast to PMA, decreased uptake of FITC-conjugated dextran. In addition, treatment with 27OH-Chol and 7αOH-Chol induced expression of mDC-specific molecules, including CD40, CD80, CD83, and CD88. Of the two oxysterols, 27OH-Chol enhanced expression of MHC class I and II molecules as well as CCR7. However, treatment with an identical concentration of cholesterol and 7-ketocholesterol did not influence adherence, uptake of FITC-conjugated dextran, and expression of the aforementioned molecules. This is the first study to report on change of monocytic cells by oxysterols to phenotypically atypical cells with some characteristics of mDCs detected in atherosclerotic lesions. We propose that a certain type of oxysterol would contribute to immune responses in atherosclerotic lesions by enhancing expression of multiple CD molecules as well as MHC molecules by monocytic cells.     

Effects of landscape and management on ground‐dwelling insect assemblages of farmland in Jeju Island,Korea

Granite‐derived soils are widespread in the farmland of Korea in general. In contrast, Jeju Island has mainly volcanic ash soils. Soils and weather condition in Jeju Island created a unique agricultural system. We identified the features of ground‐dwelling insects in farmlands of Jeju Island. This study was conducted in four areas (Samdal‐ri and Susan‐ri in Seogwipo city, and Dongmyeong‐ri and Suwon‐ri in Jeju city) in Jeju Island, Korea. Field surveys were carried out twice in summer (June) and autumn (September) in 2013. Ground‐dwelling insects were sampled quantitatively by using pitfall traps. As a result, in total 3322 individuals, 137 species, 48 families and 8 orders were investigated in farmlands of Jeju Island. Especially, members of Coleoptera and Hymenoptera accounted for a large proportion of ground‐dwelling insect communities. The numbers of species and individuals for major taxonomic groups showed significant regional and seasonal differences. This study implied that the seasonal and regional differences of ground‐dwelling insect communities were affected by surrounding land use patterns, life history patterns of each taxonomic group and farmland management.     

Prime-boost immunization with DNA vaccine: mucosal route of administration changes the rules

In this study we assessed prime-boost immunization strategies with a DNA vaccine (gB DNA) and attenuated recombinant vaccinia virus vector (rvacgB), both encoding the gB protein of HSV, for their effectiveness at inducing mucosal as well as systemic immunity to HSV. Confirming the reports of others, systemic priming with gB DNA and systemic boosting with rvacgB were the most effective means of inducing serum Ab and splenic T cell responses. Nevertheless, the systemic prime-boost approach failed to induce detectable humoral or T cell responses at mucosal sites. However, such responses, at both proximal and distal locations, were induced if immunizations, especially the priming dose, were administered mucosally. Curiously, whereas optimal immunity with systemic priming and boosting occurred when gB DNA was used to prime and rvacgB was used as a boost, mucosal responses were optimal when animals were mucosally primed with rvacgB and boosted with gB DNA given mucosally. Furthermore, notable mucosal responses also occurred in animals mucosally primed with rvacgB and subsequently boosted systemically with gB DNA. Because the mucosal prime-boost immunization protocol also induced excellent systemic immune responses, the approach should be useful to vaccinate against agents for which both mucosal and systemic immunity are important for protection.     

Influence of DNA encoding cytokines on systemic and mucosal immunity following genetic vaccination against herpes simplex virus

The aim of our investigation was to improve the effectiveness of DNA vaccines against herpes simplex virus (HSV) infection. We chose coimmunization with DNA encoding cytokines known to emphasize components of immune defense that best correlate with immune protection. These include interferon-producing T and NK cells and the IgG2a isotype immunoglobulin. Our results show that the coadministration of plasmid DNA encoding IL-12 or IL-18 along with glycoprotein B (gB) DNA improves immune induction. Recipients of the coimmunization procedure had elevated humoral as well as IFN-gamma-producing T cell responses and showed greater resistance to vaginal challenge with a lethal dose of HSV-1. The adjuvant effects were observed when the vaccines were administered either systemically or mucosally. By most assays, the adjuvant effect of IL-18 was superior to IL-12, although gB DNA plus IL-18 failed to induce levels of immunity achieved by UV-inactivated HSV immunization. Mucosal immunization proved as an effective means of inducing systemic immunity, but was less effective than the systemic route for inducing protection from vaginal challenge. Our results also demonstrated that protection from such challenges was mainly a property of IFN-gamma. Thus, immunized IFN-gamma-/- mice remained susceptible to challenges even while generating readily measurable immune responses. The approach of using DNA vaccines combined with DNA encoding cytokines holds promise and represents a potentially useful approach for vaccines.     

On the mechanisms of T cell silencing by IL-10 DNA: direct and indirect inhibition of T cell functions

Previously we reported that mucosal IL-10 DNA administration resulted in long-term suppression of virus-induced inflammatory responses by silencing Th1-type CD4+ T cell functions. However, the mechanism by which IL-10 silences the activity of CD4+ T cells was not clear. The present report has shown that mucosal IL-10 DNA administration led to the reduction of reactivity of T cells following TCR stimulation. IL-10 DNA also downregulated APC functions to stimulate T cells but the effect was temporary. Bystander suppression, including that of IL-10 producing regulatory cells, appeared not to be directly involved in the inhibition of T cell reactivity because both anti-IL-10 and anti-IL-10R could not block the suppression of T cell functions. This silenced state could be maintained following adoptive transfer to untreated animals. The nature of the silencing appears to be a reversible anergic state since Ag stimulation in the presence of exogenous IL-2 restored T cell reactivity. Furthermore, IL-10-induced silenced T cells could be induced in vitro by culturing the T cells with rIL-10 in the presence or the absence of antigen stimulation. This state persisted in the absence of rIL-10 and persisted for at least 3 days. A more notable effect, however, was observed when the T cells were incubated with IL-10 in the presence of APC and Ag. These results indicate that IL-10 induced a long-term silenced state in T cells by direct and indirect inhibition of T cell functions.     

Distinct Upstream Role of Type I IFN Signaling in Hematopoietic Stem Cell-Derived and Epithelial Resident Cells for Concerted Recruitment of Ly-6Chi Monocytes and NK Cells via CCL2-CCL3 Cascade

Type I interferon (IFN-I)-dependent orchestrated mobilization of innate cells in inflamed tissues is believed to play a critical role in controlling replication and CNS-invasion of herpes simplex virus (HSV). However, the crucial regulators and cell populations that are affected by IFN-I to establish the early environment of innate cells in HSV-infected mucosal tissues are largely unknown. Here, we found that IFN-I signaling promoted the differentiation of CCL2-producing Ly-6C^hi monocytes and IFN-γ/granzyme B-producing NK cells, whereas deficiency of IFN-I signaling induced Ly-6C^lo monocytes producing CXCL1 and CXCL2. More interestingly, recruitment of Ly-6C^hi monocytes preceded that of NK cells with the levels peaked at 24 h post-infection in IFN-I–dependent manner, which was kinetically associated with the CCL2-CCL3 cascade response. Early Ly-6C^hi monocyte recruitment was governed by CCL2 produced from hematopoietic stem cell (HSC)-derived leukocytes, whereas NK cell recruitment predominantly depended on CC chemokines produced by resident epithelial cells. Also, IFN-I signaling in HSC-derived leukocytes appeared to suppress Ly-6G^hi neutrophil recruitment to ameliorate immunopathology. Finally, tissue resident CD11b^hiF4/80^hi macrophages and CD11c^hiEpCAM⁺ dendritic cells appeared to produce initial CCL2 for migration-based self-amplification of early infiltrated Ly-6C^hi monocytes upon stimulation by IFN-I produced from infected epithelial cells. Ultimately, these results decipher a detailed IFN-I–dependent pathway that establishes orchestrated mobilization of Ly-6C^hi monocytes and NK cells through CCL2-CCL3 cascade response of HSC-derived leukocytes and epithelium-resident cells. Therefore, this cascade response of resident–to-hematopoietic–to-resident cells that drives cytokine–to-chemokine–to-cytokine production to recruit orchestrated innate cells is critical for attenuation of HSV replication in inflamed tissues.     

Aerobic training increases the expression of adiponectin receptor genes in the peripheral blood mononuclear cells of young men

Little is known about the effect of exercise training on the expression of adiponectin receptor genes in peripheral blood mononuclear cells (PBMCs). In this study, we investigated the effects of aerobic training on the expression of AdipoR1 and AidpoR2 mRNAs in PBMCs, whole body insulin sensitivity, and circulating adiponectins in men. Thirty young men were randomly assigned to either a control (n=15) or an exercise (n=15) group. Subjects assigned to the exercise group underwent a 12-week jogging and/or running programme on a motor-driven treadmill at an intensity of 60%-75% of the age-based maximum heart rate with duration of 40 minutes per session and a frequency of 5 days per week. Two-way mixed ANOVA with repeated measures was used to test any significant time-by-group interaction effects for the measured variables at p=0.05. We found significant time-by-group interaction effects for waist circumference (p=0.001), VO_2max (p<0.001), fasting insulin (p=0.016), homeostasis model assessment for insulin resistance (HOMA-IR) (p=0.010), area under the curve (AUC) for insulin response during the 75-g oral glucose tolerance test (p=0.002), high-molecular weight (HMW) adiponectin (p=0.016), and the PBMC mRNA levels of AdipoR1 (p<0.001) and AdipoR2 (p=0.001). The exercise group had significantly increased mRNA levels of AdipoR1 and AdipoR2 in PBMCs, along with increased whole body insulin sensitivity and HMW adiponectin, decreased waist circumference, and increased VO_2max compared with the control group. In summary, the current findings suggest that exercise training modulates the expression of AdipoR1 and AdipoR2 mRNAs in PBMCs, implying that manipulation of the expression of these genes could be a potential surrogate for lifestyle intervention-mediated improvements of whole body insulin sensitivity and glucose homeostasis.     

Similar hypotensive responses to resistance exercise with and without blood flow restriction

Low intensity resistance exercise (RE) with blood flow restriction (BFR) has gained attention in the literature due to the beneficial effects on functional and morphological variables, similar to those observed during traditional RE without BFR, while the effects of BFR on post-exercise hypotension remain unclear. The aim of the present study was to compare the blood pressure (BP) response of trained normotensive individuals to RE with and without BFR. In this cross-over randomized trial, eight male subjects (23.8 ± 4 years, 74 ± 3 kg, 174 ± 4 cm) completed two exercise protocols: traditional RE (3 x 10 repetitions at 70% one-repetition maximum [1-RM]) and low intensity RE (3 x 15 repetitions at 20% 1-RM) with BFR. Blood pressure measurements were performed after 15 min of seated rest (0), immediately after and 10 min, 20 min, 30 min, 40 min, 50 min and 60 min after the experimental sessions. Similar hypotensive effects for systolic BP (SBP) were observed for both protocols (P < 0.05) after exercise, with no differences between groups (P > 0.05) and no statistically significant difference for diastolic BP (P > 0.05). These results suggest that in normotensive trained individuals, both traditional RE and RE with BFR induce hypotension for SBP, which is important to prevent cardiovascular disturbances.