Natural CD8+CD122+ T cells are more potent in suppression of allograft rejection than CD4+CD25+ regulatory T cells

Despite extensive studies on CD4+CD25+ regulatory T cells (Tregs), their application in adoptive transfer therapies is still not optimal in immune-competent wild-type (WT) animal models. Therefore, it is compelling to search for more potent Tregs for potential clinical application. Mounting evidence has shown that naturally occurring CD8+CD122+ T cells are also Tregs. However, their suppression in allograft rejection, efficiency in suppression and underlying mechanisms remain unclear. Using a murine allotransplantation model, we reported here that CD8+CD122+ Tregs were actually more potent in suppression of allograft rejection and underwent more rapid homeostatic proliferation than their CD4+CD25+ counterparts. Moreover, they produced more IL-10 and were more potent in suppressing T cell proliferation in vitro. Deficiency in IL-10 in CD4+CD25+ and CD8+CD122+ Tregs resulted in their reduced but equal suppression in vivo and in vitro, suggesting that IL-10 is responsible for more effective suppression by CD8+CD122+ than CD4+CD25+ Tregs. Importantly, transfer of CD8+CD122+ Tregs together with the administration of recombinant IL-15 significantly prolonged allograft survival in WT mice. Thus, for the first time, we demonstrate that naturally arising CD8+CD122+ Tregs not only inhibit allograft rejection but also exert this suppression more potently than their CD4+CD25+ counterparts. This novel finding may have important implications for tolerance induction.

Photodegradation of organic matter in fresh garbage leachate using immobilized nano-sized TiO2 as catalysts

Two immobilized nano-sized TiO2 catalysts, TiO2/activated carbon (TiO2/AC) and TiO2/silica gel (SG) (TiO2/SG), were prepared by the sol-gel method, and their use in the photocatalytic degradation of organic matter in fresh garbage leachate under UV irradiation was investigated. The influences of the catalyst dosage, the initial solution pH, H2O2 addition and the reuse of the catalysts were evaluated. The degradation of organic matter was assessed based on the decrease of the chemical oxygen demand (COD) in the leachate. The results indicated that the degradation of the COD obeyed first-order kinetics in the presence of both photocatalysts. The degradation rate of COD was found to increase with increasing catalyst dosage up to 9 g/L for TiO2/AC and 6 g/L for TiO2/SG, above which the degradation began to attenuate. Furthermore, the degradation rate first increased and then decreased as the solution pH increased from 2 to 14, and the degradation rate increased as the amount of H2O2 increased to 2.93 mM, after which it remained constant. No obvious decrease in the rate of COD degradation was observed during the first four repeated uses of the photocatalysts, indicating that the catalysts could be recovered and reused. Compared with TiO2/AC, TiO2/SG exhibited higher efficiency in photocatalyzing the degradation of COD in garbage leachate.

Cost analysis of adjuvant therapy with XELOX or FOLFOX4 for colon cancer

AIM

XELOX and FOLFOX4 have both been recommended as adjuvant therapy for stage III colon cancer. This study compared the two regimens in terms of monetary costs, assuming equal efficacy of the therapies.

METHOD

A retrospective financial audit was conducted of the medical records of patients treated with XELOX or FOLFOX4. All itemized expenses were classified as direct (chemotherapy, hospitalization, venous access and tests), related to adverse effects due to the adjuvant therapy, or societal (travel and time costs). The cost of supportive care was not included.

RESULTS

XELOX involved less total cost to the patient than FOLFOX4 (a difference of US$2857.68), fewer costs related to adverse effects ($668.97), and less travel ($26.07) and time ($390.93) expenditure per patient.

CONCLUSION

The results indicate that, overall, XELOX is a more affordable option than FOLFOX4 in China.

Mitotic and meiotic behavior of rye chromosomes in wheat - Psathyrostachys huashanica amphiploid x triticale progeny

The dynamics of rye chromosomes during mitosis and meiosis was analyzed in a subset comprising 33 F3 lines from the cross of wheat, Psathyrostachys huashanica amphiploid (AABBDDNsNs) and hexaploid triticale (AABBRR), as visualized by genomic in situ hybridization. The results indicated that 31 of the total lines contained 4-14 rye chromosomes. Twenty-eight combinations had more rye chromosomes than the F1 hybrids, suggesting the occurrence of spontaneous quantitative increment. No P. huashanica chromosomes were detected in all of the combinations tested. Mitotic analysis showed that rye chromosomes progressed normally with the wheat counterparts without loss. However, abnormal meiosis was found in almost all lines. Similar progression between wheat and rye genomes appeared from interphase to metaphase I. It was at anaphase I that many rye univalents lagged behind those of wheat, followed by equational division. This resulted in the formation of chromosomal segments and micronuclei at telophase I or II. Micronuclei could also be generated from the immobilized univalents in the periphery of cells. Synapsis and translocations between wheat and rye genomes, chromosome bridges, and unreduced gametes were detected. Therefore, it is proposed that rye chromosome elimination may involve chromatid lagging, fragmentation and micronucleation, or the immobilization of certain univalents during meiosis instead of mitosis in the relatively advanced generations. This mechanism, together with spontaneous incremental increase of rye chromosome number, permitted the generation of various germplasms for wheat improvement.

Two years efficiency of lamivudine and adefovir dipivoxil combined therapy in chronic hepatitis B patients

BACKGROUND

Lamivudine (LAM) and adefovir (ADV) are widely used in most Asian countries, though monotherapy is associated with the occurrence of resistance.

AIM

To evaluate the efficiency of LAM and ADV combined treatment of chronic hepatitis B patients with compensated cirrhosis.

PATIENTS AND METHODS

206 eligible Chinese patients were randomly assigned in a 1:1 ratio to receive either LAM or ADV for the first 24 weeks. According to virologic response at 24 weeks, the patients either continued to monotherapy or switched to combined therapy for 48 weeks. After 48 weeks, all patients received LAM and ADV combined therapy for 96 weeks.

RESULTS

Serum HBV DNA levels significantly decreased in patients with ADV or LAM monotherapy and continuously reduced after the combined therapy. Serum ALT normalized rate were 88.24% and 81.37% at week 48, and 95.74% and 87.36% at week 96 in ADV and LAM group respectively, comparing to 60.78% and 56.73% in ADV and LAM groups at baseline. The accumulated virological breakthrough rate at week 48 and 96 was significantly higher in LAM group.

CONCLUSIONS

Both combination strategies were resulted in the long term virological, biochemical improvement in Chinese chronic hepatitis B patients with compensated cirrhosis.

Inhibition of hepatitis B virus gene expression by small interfering RNAs targeting cccDNA and X antigen

To test the possible inhibition of hepatitis B virus (HBV) replication and expression by small interfering RNAs (siRNAs) targeting simultaneously covalenthy closed circular DNA (dnacccDNA) and X antigen, corresponding recombinant plasmids were transfected into HepG2.2.15 cells and the levels of cccDNA, HBXAg, HBcAg, and HBeAg were assayed at various times post transfection. As expected, the single siRNAs showed marked inhibitory effects but their combination was even more efficient. These results provide a new insight into the development of a potential anti-HBV strategy of enhancing the efficacy of individual antivirals and overcoming the high mutation rate of HBV.

One Alpha-hydroxycholecalciferol Improves Growth Performance, Tibia Quality, and Meat Color of Broilers Fed Calcium- and Phosphorus-Deficient Diets

An experiment was conducted to evaluate the effects of one alpha-hydroxycholecalciferol (1α-OH D₃) on growth performance, tibia quality, and skin and meat color in broilers fed calcium (Ca)- and phosphorus (P)-deficient corn-soybean meal diets. A total of 288 male Ross broilers, at 21 days of age, were randomly assigned to three treatments with eight cages per treatment. Three levels of 1α-OH D₃ (0, 5, and 10 μg/kg) were added to a basal diet (0.50% Ca, 0.13% non-phytate phosphorus (NPP), and 0.35% total phosphorus (tP)) without vitamin D₃. As a result of this study, the addition of 1α-OH D₃ increased body weight gain (p<0.001), feed intake (p = 0.007), feed efficiency (p<0.001), tibia weight (p = 0.002), length (p<0.001), breaking-strength (p = 0.012), ash (p<0.001), Ca (p<0.001), and P content (p = 0.004). Dietary 1α-OH D₃ enhanced breast meat yellowness (p = 0.015) and the length and weight of the small intestine of the broilers. Moreover, 1α-OH D₃ decreased serum Ca concentration (p = 0.074) and breast meat redness (p = 0.010). These results indicate that the 1α-OH D₃ improves growth, tibia quality, and meat color in broilers fed Ca- and P-deficient corn-soybean meal diets.

Hepatitis B virus suppresses the functional interaction between natural killer cells and plasmacytoid dendritic cells

Natural killer cells (NK) are one of the key players in the eradication and control of viral infections. Infections with the hepatitis B virus (HBV) may lead to persistence in a subgroup of patients, and impaired NK cell functions have been observed in these patients. Crosstalk with other immune cells has been shown to modulate the function of NK cells. We studied the functional crosstalk between NK cells and plasmacytoid dendritic cell (pDC) and its modulation by HBV. Healthy human peripheral blood-derived NK cells and pDC were purified and cocultured in the presence or absence of HepG2.2.15-derived HBV under various in vitro conditions. The functionality of NK cells was assessed by evaluation of activation markers, cytokine production and cytotoxicity of carboxyfluorescein succinimidyl ester-labelled K562 target cells by flow cytometry or immunoassays. Additionally, the crosstalk was examined using NK and pDC from patients with chronic HBV. The activation of NK cells in cocultures with pDC, as demonstrated by CD69, CD25 and HLA-DR, was not affected by the presence of HBV. Similarly, when cocultured with pDC, the cytotoxic potential of NK cells was not influenced by HBV. However, HBV significantly inhibited pDC-induced IFN-γ production by NK cells both in the presence and in the absence of CpG. As HBV did not affect cytokine-induced IFN-γ production by NK cells cultured alone, the suppressive effect of HBV on NK cell function was mediated via interference with pDC-NK cell interaction. In contrast to other viruses, HBV does not activate pDC-NK cell interaction but inhibits pDC-induced NK cell function. In parallel with NK cells of patients with chronic HBV, which show diminished cytokine production with normal cytotoxicity, HBV specifically suppressed pDC-induced IFN-γ production by NK cells without affecting their cytolytic ability. These data demonstrate that HBV modulates pDC-NK cell crosstalk, which may contribute to HBV persistence.

Shorter durations and lower doses of peginterferon alfa-2a are associated with inferior hepatitis B e antigen seroconversion rates in hepatitis B virus genotypes B or C

As there is currently a lack of consensus on the most appropriate dose and duration of peginterferon alfa-2a (PEG-IFNα-2a) therapy in hepatitis B e antigen (HBeAg)-positive patients, the efficacy and safety of either 24 or 48 weeks' duration and 90 μg/week or 180 μg/week doses were compared. HBeAg-positive patients (n = 544; 34% genotype B, 51% genotype C) were randomized to receive PEG-IFNα-2a (2 × 2 factorial design) for 24 or 48 weeks and at 90 μg/week or 180 μg/week and included in the per-protocol population. The primary efficacy endpoint of the noninferiority study was HBeAg seroconversion 6 months posttreatment. The prespecified odds ratio (OR) noninferiority margin was 1.88 with a one-sided significance level of 0.025. The highest rates of HBeAg seroconversion 6 months posttreatment were in the 180/48 arm (36.2% versus 14.1%-25.8% in the other arms). When the dose and duration arms were pooled, the OR for noninferiority of 24 weeks versus 48 weeks was 2.17 (95% confidence interval [CI] 1.43, 3.31; P = 0.749) and for 90 μg versus 180 μg was 1.79 (95% CI 1.18, 2.72; P = 0.410). As the upper limit of the 95% CI of the ORs were >1.88, 24 weeks were inferior to 48 weeks and 90 μg/week was inferior to 180 μg/week. The highest rates of response in the 180/48 arm were achieved by patients with HBsAg <1,500 IU/mL at Week 12 (58%) or Week 24 (57%), whereas patients with HBsAg >20,000 IU/mL did not respond. Adverse events were typical of those associated with PEG-IFNα-2a.

CONCLUSION

Compared with lower doses and shorter durations, the licensed PEG-IFNα-2a treatment regimen (180 μg/48 weeks) was the most efficacious and beneficial for HBeAg-positive patients predominantly infected with hepatitis B virus genotypes B or C.

Biomimetic approach for root caries prevention using a proanthocyanidin-rich agent

The aim of this study was to evaluate the effects of a proanthocyanidin-rich grape seed extract (GSE) on the in vitro demineralization of root dentine. Root fragments were obtained from sound human teeth. The fragments were randomly assigned to different treatments solutions: GSE, fluoride (F), GSE+F and distilled water (control). Samples were treated daily for 30 min and subjected to a pH cycling artificial caries protocol using demineralization cycles (2.2 mM CaCl(2)×H(2)O, 2.2 mM KH(2)PO(4), 50 mM acetic acid, pH 4.3) for 6 h and remineralization cycles (20 mM HEPES, 2.25 mM CaCl(2)×H(2)O, 1.35 mM KH(2)PO(4), 130 mM KCl, pH 7.0) for 17.5 h. Mineral loss (ΔZ) and lesion depth (LD) were determined after 18 days of treatment/pH cycling, by transverse microradiography. GSE was able to minimize ΔZ and LD compared with the control group (p < 0.0001). The GSE+F and F groups showed the lowest values of ΔZ and LD (p < 0.05), with no statistically significant differences between them (p = 0.554 and p = 0.726, respectively). A biomimetic approach to strengthen root dentine using GSE results in decreased rates of root demineralization and may be used in conjunction with F to prevent root caries.

Randomised clinical trial: efficacy of peginterferon alfa-2a in HBeAg positive chronic hepatitis B patients with lamivudine resistance

BACKGROUND

Previous studies suggested that a finite course of peginterferon alfa-2a may offer an alternative rescue therapy for patients with lamivudine resistance. However, because of the limitation of study design and small sample size, it is difficult to make definitive conclusion.

AIM

To explore the role of peginterferon alfa-2a, in the rescue treatment of HBeAg-positive chronic hepatitis B patients with lamivudine resistance.

METHODS

In this randomised study, chronic hepatitis B patients with lamivudine resistance were treated with peginterferon alfa-2a for 48 weeks (n=155) or adefovir for 72 weeks (n=80). All enrolled patients were treated with lamivudine for the first 12weeks.

RESULTS

At 6 months posttreatment, 14.6% (18/123) of peginterferon alfa-2a-treated patients achieved HBeAg seroconversion, in contrast to 3.8% (3/80) of adefovir-treated patients after 72 weeks continuous therapy (P=0.01). For peginterferon alfa-2a-treated patients, the rate of HBeAg seroconversion at week 72 was significantly higher in patients who had HBsAg decline >0.5 Log(10) IU/mL from baseline at week 24, compared with patients with HBsAg decline ≤0.5 Log(10) IU/mL from baseline at week 24 (25.5% vs. 7.7%, P=0.01). After 72 weeks continuous adefovir treatment, 22.5% of patients achieved HBV DNA <80 IU/mL, compared with 10.6% in peginterferon alfa-2a-treated patients at 6months off-treatment (P=0.02).

CONCLUSIONS

Overall, the response to peginterferon alfa-2a among patients with lamivudine resistance was suboptimal. HBeAg seroconversion rate at week 72 by 48 weeks peginterferon alfa-2a treatment was higher than continuous adefovir therapy. Monitoring HBsAg levels can help to predict response to peginterferon alfa-2a.

Genetic architecture of the circadian clock and flowering time in Brassica rapa

The circadian clock serves to coordinate physiology and behavior with the diurnal cycles derived from the daily rotation of the earth. In plants, circadian rhythms contribute to growth and yield and, hence, to both agricultural productivity and evolutionary fitness. Arabidopsis thaliana has served as a tractable model species in which to dissect clock mechanism and function, but it now becomes important to define the extent to which the Arabidopsis model can be extrapolated to other species, including crops. Accordingly, we have extended our studies to the close Arabidopsis relative and crop species, Brassica rapa. We have investigated natural variation in circadian function and flowering time among multiple B. rapa collections. There is wide variation in clock function, based on a robust rhythm in cotyledon movement, within a collection of B. rapa accessions, wild populations and recombinant inbred lines (RILs) derived from a cross between parents from two distinct subspecies, a rapid cycling Chinese cabbage (ssp. pekinensis) and a Yellow Sarson oilseed (ssp. trilocularis). We further analyzed the RILs to identify the quantitative trait loci (QTL) responsible for this natural variation in clock period and temperature compensation, as well as for flowering time under different temperature and day length settings. Most clock and flowering-time QTL mapped to overlapping chromosomal loci. We have exploited micro-synteny between the Arabidopsis and B. rapa genomes to identify candidate genes for these QTL.

The 3Ns chromosome of Psathyrostachys huashanica carries the gene(s) underlying wheat stripe rust resistance

Stripe rust (Puccinia striiformis tritici (Pst)) is one of the most destructive diseases of wheat in the world. Exploiting and utilizing stripe rust resistance genes of wild species has become an essential strategy for resistance breeding. Psathyrostachyshuashanica Keng ex Kuo is a wild species in Triticeae that has been used for wheat improvement because of its high resistance or immunity to stripe rust. In this study, 9 wheat-P. huashanica addition lines were characterized by Giemsa C-banding, genomic in situ hybridization (GISH), and disease resistance evaluation. Giemsa C-banding and GISH demonstrated that lines 163-5, 165-1, 183-5, 240-3, and 240-4 are P. huashanica 3Ns chromosome monosomic addition lines; lines 183-1 and 183-20 are P. huashanica 3Ns chromosome disomic addition lines; line 165-20 is a P. huashanica 3Ns and 4Ns chromosomes double disomic addition line, and line 219-1 is a P. huashanica 1Ns and 3Ns/5A chromosomes double disomic addition-substitution line. All these addition lines with P. huashanica 3Ns chromosome(s) expressed high resistance or immunity to stripe rust. By comparing the series of wheat-P. huashanica chromosome addition lines, we concluded that the P. huashanica 3Ns chromosome carries the gene(s) for resistance or immunity to stripe rust. These addition lines can be used as a donor source of novel stripe rust resistance to wheat breeding programs.

Mechanical Properties and Porosity of Organo-Silicate Glass (OSG) Low-k Dielectric Films

Low-k material integration issues that plague the microelectronics industry include the compromise in mechanical properties that one incurs in abandoning fully dense silica dieletrics. Typical elastic moduli of OSG low-k dieletric films are 2-10 GPa with corresponding hardnesses of 0.5 to 1.5 GPa. In the present study, the hardness and elastic modulus properties measured by nanoindentation of porous silica based low-k films are correlated with in initial estimates of density using a novel technique of spectroscopic ellispsometry. Transmission electron microscopy and X-ray photoelectron spectroscopy show the structural and chemical similarity of the films. Nanoindentation and spectroscopic ellipsometry results reflect significant deviations in material behavior from that expected from a simple model of silica (SiO2) with included voids or porosity, suggesting that the methyl groups are actively participating in the mechanical and optical properties of the material.

Relationship between serum hepatitis B virus DNA and surface antigen with covalently closed circular DNA in HBeAg-negative patients

Hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) is responsible for viral persistence. This study aimed to investigate the serum surrogate markers for cccDNA and to evaluate the intrahepatic viral events associated with disease activity in HBeAg-negative chronic hepatitis B patients. Thirty-three treatment-naïve patients with a negative HBeAg who had a liver biopsy were studied. Active disease was defined as a serum alanine aminotransferase >40 IU/L and a serum HBV DNA >10,000 copies/ml. This study showed significant correlation between serum HBV DNA and both log cccDNA (r = 0.41, P = 0.018) and log total intrahepatic HBV DNA (r = 0.71, P < 0.0001). No significant correlation was observed between serum HBsAg and log cccDNA (P = 0.15) or log total intrahepatic HBV DNA (P = 0.97). Fourteen and 19 patients had inactive and active disease, respectively. The median log cccDNA and log total intrahepatic HBV DNA (copies/10(6) cells) were significantly higher in patients with active disease compared with those with inactive disease (4.11 vs. 3.53, P = 0.03 and 5.46 vs. 4.64, P < 0.001, respectively). The HBV replicative efficiency, defined as the ratio of serum HBV DNA to cccDNA, was approximately 20% higher in patients with active disease. No significant difference was observed in the HBsAg levels and the ratio of serum HBsAg to cccDNA between the two groups. In conclusion, serum HBV DNA, but not HBsAg, reflects the amount of cccDNA and the replication efficiency of HBV in patients with HBeAg-negative chronic hepatitis B.

Monoclonal antibody treatment to prolong the secondary cardiac allograft survival in alloantigen-primed mice

We have previously shown that costimulation blockade using a combination of monoclonal antibodies (mAbs) - CTLA4Ig, antibodies to CD154, LFA-1, and OX40L - can induce tolerance of cardiac allografts in mice with adoptively transferred CD4(+) memory T cells [1]. However, the effect of costimulatory blockade in secondary allograft rejection has not been studied. B6 mice that rejected BALB/c skin grafts for more than 4 weeks (defined as alloantigen-primed mice) were used as recipients. The recipient mice were treated with the mAbs to CD154, LFA-1, OX40L, and CD122 on days 0, 2, 4, and 6 after the secondary transplantation of BALB/c heart. The mean survival time (MST) of secondary cardiac allografts in rats treated with antibodies to CD154 and LFA-1 (2-antibodies approach) and those treated with antibodies to CD154, LFA-1, OX40L, and CD122 (4-antibodies approach) was greater than that of the controls (MST = 6.7 days, 22.2 days, and 3.2 days, respectively). The 4-antibodies approach prevented lymphocytic infiltration in the grafts, inhibited memory T-cells proliferation in the spleen, increased IL-10 secretion in the serum, and enhanced the expression of CD4(+) Foxp3(+) regulatory T cells (Tregs) in spleen. Expression levels of alloreactive antibodies were high in the recipient mice of experimental and control groups. Inhibiting the memory T cells by costimulation blockade extended allograft survival in secondary transplant models but could not induce tolerance of graft. Alloreactive antibodies may participate in alloresponse and play an important role in secondary cardiac allograft rejection.