Evaluation of two different adjuvants with immunogenic uroplakin 3A-derived peptide for their ability to evoke an immune response in mice

Rationale

Organ- or tissue-specific antigens produced by normal tissue or by cancer cells could be used in cancer immunotherapy, to target the tumor. In our previous study, we induced T-cell-mediated, bladderspecific autoimmunity by targeting the bladder-specific protein Uroplakin 3A (UPK3A). UPK3A is a well-chosen target for developing an autoimmune response against bladder cancer since the antigen is also expressed in bladder tumors. To use this peptide, which was derived from the UPK3A protein in a bladder cancer vaccine study, it is necessary to induce a strong immune response. In this study, we aimed to develop a robust immune response in BALB/c mice using the well-characterized keyhole limpet hemocyanin (KLH)-conjugated peptide antigen (UPK3A 65-84) conjugated with an immunogenic carrier protein. In combination with the peptide, we used either Freund’s complete adjuvant (CFA) or CpG (cytosine-phosphate-guanine oligonucleotides) as effective adjuvants in order to overcome tumor tolerance.

Objectives

The immune response evoked by UPK3A 65-84 peptide, using two different adjuvants, was compared by detection of changes in the proliferative response of immune cells, in the cytokine profile, and in the immune cell populations.

Findings

We demonstrated that CpG, combined with KLH-UPK3A 65-84, promoted a more robust immune response, via induction of higher IL-2, IFN-γ, TNF-α, IL-17 production and activation of more immune cells (CD4⁺ T cells, CD8⁺ T cells, NK cells CD11b, CD45), than CFA and the KLHUPK3A 65-84.

Conclusion

CpG as an adjuvant combined with KLH-UPK3A 65-84 could be used in preclinical models of bladder cancer for the development of cancer immunotherapy strategies.

     

Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite

Organolead halide perovskites currently are the new front‐runners as light absorbers in hybrid solar cells, as they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution‐based fabrication routes. Long‐term stability remains a major obstacle for application on an industrial scale. Here, it is demonstrated that significant decomposition effects already occur during annealing of a methylammonium lead triiode perovskite at 85 °C even in inert atmosphere thus violating international standards. The observed behavior supports the view of currently used perovskite materials as soft matter systems with low formation energies, thus representing a major bottleneck for their application, especially in countries with high average temperatures. This result can trigger a broader search for new perovskite families with improved thermal stability.     

TbPIF1, a Trypanosoma brucei Mitochondrial DNA Helicase, Is Essential for Kinetoplast Minicircle Replication

Kinetoplast DNA, the trypanosome mitochondrial genome, is a network of interlocked DNA rings including several thousand minicircles and a few dozen maxicircles. Minicircles replicate after release from the network, and their progeny reattach. Remarkably, trypanosomes have six mitochondrial DNA helicases related to yeast PIF1 helicase. Here we report that one of the six, TbPIF1, functions in minicircle replication. RNA interference (RNAi) of TbPIF1 causes a growth defect and kinetoplast DNA loss. Minicircle replication intermediates decrease during RNAi, and there is an accumulation of multiply interlocked, covalently closed minicircle dimers (fraction U). In studying the significance of fraction U, we found that this species also accumulates during RNAi of mitochondrial topoisomerase II. These data indicate that one function of TbPIF1 is an involvement, together with topoisomerase II, in the segregation of minicircle progeny.     

Pentose phosphate pathway,glutathione-dependent enzymes and antioxidant defense during oxidative stress in diabetic rodent brain and peripheral organs: effects of stobadine and vitamin E

The aim of the present study was to investigate the effects of treatment with antioxidant stobadine (ST) on the activities of enzymes related with pentose phosphate pathway and glutathione-dependent metabolism and the other markers of oxidative stress in brain and peripheral organs of diabetic rats, and to compare the effects of ST treatment alone with the effects of treatments with another antioxidant vitamin E and ST plus vitamin E. Rats were made diabetic by the injection of streptozotocin (STZ; 55 mg/kg IP), and, 2 days later, some control and diabetic rats were left untreated or treated with ST (24.7 mg/kg/day, orally), vitamin E (400–500 U/kg/day, orally), or both substances together. In the brain, although 6-phosphogluconate dehydrogenase activity (6-PGD) did not change, glucose-6-phosphate dehydrogenase activity (G-6PD) was markedly increased in diabetic rats compared with controls; only combined treatment with ST and vitamin E produced a partial prevention on this alteration. The aorta G-6PD and 6-PGD of diabetic rats were 52% and 36% of control values, respectively. Neither single treatments with each antioxidant nor their combination altered the G-6PD and 6-PGD in aorta of diabetic rats. Glutathione peroxidase (GSHPx) activity was increased by STZ-diabetes in brain, heart, and kidney. In diabetic brain, vitamin E alone or combination with ST kept GSHPx at normal levels. Diabetes-induced stimulation in GSHPx did not decrease in response to the treatment with vitamin E in heart and kidney, but was greatly prevented by ST alone. The activity of glutathione reductase (GR) was decreased in brain and heart of diabetic rats. The treatment with each antioxidant or with a combination of both agents completely prevented this deficiency and resulted in further activation of GR in diabetic tissues. Glutathione S-transferase (GST) activity did not significantly change in diabetic brain and aorta. GST was stimulated by all treatment protocols in the brain of diabetic rats and was depressed in aorta of control rats. Catalase (CAT) was activated in diabetic heart but depressed in diabetic kidney. Diabetes-induced abnormalities in CAT activity did not respond to vitamin E alone in heart, was moderately ameliorated by the treatment with this vitamin in kidney, and was completely prevented by ST alone in both tissues. Superoxide dismutase (SOD) activity of brain and heart was unchanged by the diabetes but inhibited in diabetic kidney after the treatment ST alone or ST plus vitamin E. The lipid peroxidation (MDA) was increased in diabetic brain and heart. ST or vitamin E alone partly prevented diabetes-induced increase in MDA in brain and heart; however, antioxidant combination achieved a completely amelioration in MDA of these tissues of diabetic rats. Kidney MDA levels were similar in control and untreated diabetic animals. ST and vitamin E treatments, when applied separately or together, significantly reduced kidney MDA in both control and diabetic rats; and the combined effect of antioxidants was greater than that of each alone. These results are consistent with the degenerative role of hyperglycemia on cellular reducing equivalent homeostasis and antioxidant defense, and provide further evidence that pharmacological intervention of different antioxidants may have significant implications in the prevention of the prooxidant feature of diabetes and protects redox status of the cells.     

Schizosacchromyces pombe Dpb2 binds to origin DNA early in S phase and is required for chromosomal DNA replication

Genetic evidence suggests that DNA polymerase epsilon (Pol epsilon) has a noncatalytic essential role during the early stages of DNA replication initiation. Herein, we report the cloning and characterization of the second largest subunit of Pol epsilon in fission yeast, called Dpb2. We demonstrate that Dpb2 is essential for cell viability and that a temperature-sensitive mutant of dpb2 arrests with a 1C DNA content, suggesting that Dpb2 is required for initiation of DNA replication. Using a chromatin immunoprecipitation assay, we show that Dpb2, binds preferentially to origin DNA at the beginning of S phase. We also show that the C terminus of Pol epsilon associates with origin DNA at the same time as Dpb2. We conclude that Dpb2 is an essential protein required for an early step in DNA replication. We propose that the primary function of Dpb2 is to facilitate assembly of the replicative complex at the start of S phase. These conclusions are based on the novel cell cycle arrest phenotype of the dpb2 mutant, on the previously uncharacterized binding of Dpb2 to replication origins, and on the observation that the essential function of Pol epsilon is not dependent on its DNA synthesis activity.     

Kinome Profiling of Regulatory T Cells: A Closer Look into a Complex Intracellular Network

Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and function of Treg is still limited and based on single kinase cascades so far. To gain a more comprehensive insight into the pathways determining Treg function we performed kinome profiling using a phosphorylation-based kinome array in human Treg at different activation stages compared to Teff. Here we have determined intriguing quantitative differences in both populations. Resting and activated Treg showed an altered pattern of CD28-dependent kinases as well as of those involved in cell cycle progression. Additionally, significant up-regulation of distinct kinases such as EGFR or CK2 in activated Treg but not in Teff not only resemble data we obtained in previous studies in the murine system but also suggest that those specific molecular activation patterns can be used for definition of the activation and functional state of human Treg. Taken together, detailed investigation of kinome profiles opens the possibility to identify novel molecular mechanisms for a better understanding of Treg biology but also for development of effective immunotherapies against unwanted T cell responses in allergy, autoimmunity and cancer.     

Direct repeats of the F plasmid incC region express F incompatibility

The nucleotide sequence of the incompatibility region incC, located at 45.8--46.4 kb on the F plasmid map, was determined. This region consists of 543 bp and contains sufficient information to code for only two small polypeptides of 34 and 30 amino acids each. Deletion of the ATG start codons for these two polypeptides has no effect on expression of incC incompatibility. A prominent feature of this sequence is the presence of five 22 bp direct repeats. A 58 bp segment of the incC region that contains two of these direct repeats was inserted into plasmid pACYC184, which is compatible with the F plasmid. The pACYC184 plasmid containing the direct-repeat sequences now expresses incompatibility with the F'lac plasmid and replication-proficient derivatives of the mini-F plasmid.     

The molecular basis of β-thalassemia in Turkey

Summary By using oligonucleotide hybridization, restriction endonuclease analysis and direct sequencing of amplified genomic DNA, we have been able to characterize 18 different mutations in the -globin genes of 161 thalassemia homozygotes and 107 -thalassemia heterozygotes from Turkey (429 -thalassemia chromosomes). Previous studies dealing with -thalassemia in Mediterranean countries have shown that, in most Mediterranean populations, only a few mutations are prevalent. In contrast, -thalassemia in Turkey does not seem to be associated with a few predominant mutations. The six most frequent alleles, IVS-I-110 (GA), IVS-I-6(TC), FSC-8 (-AA), IVS-I-1(GA), -30(TA) and FSC-5 (CT), account for only 69.3% of the disease genes; indeed, all 26 mutations assayed represent 85.8% of the disease genes, confirming the considerable molecular heterogeneity of -thalassemia among Turks, and indicating the possible presence of rare, previously undefined, mutations in the population. Two mutations observed in this study, IVS-I-116 (TG) and Cd44(-C), have not been reported in the Turkish population to date. Since preventive medical services, such as genetic counseling and prenatal diagnosis, are greatly improved by detailed knowledge of the molecular pathology of thalassemia, we strongly believe that the presented data will facilitate the intended establishment of a prenatal diagnosis center, based on DNA analysis, in Turkey.