Background: Modulated electro-hyperthermia (mEHT), a non-invasive intervention using 13.56 MHz radiofrequency, can selectively target cancers due to their elevated glycolysis (Warburg-effect), extracellular ion concentration and conductivity compared to normal tissues. We showed earlier that mEHT alone can provoke apoptosis and damage associated molecular pattern (DAMP) signals in human HT29 colorectal cancer xenografts of immunocompromised mice.Materials: Here we tested the mEHT induced stress and immune responses in C26 colorectal cancer allografts of immunocompetent (BALB/c) mice between 12-72 h post-treatment. The right side of the symmetrical tumors grown in both femoral regions of mice were treated for 30 minutes, while the left side tumors served for untreated controls.Results: Loco-regional mEHT treatment induced an ongoing and significant tumor damage with the blockade of cell cycle progression indicated by the loss of nuclear Ki67 protein. Nuclear shrinkage, apoptotic bodies and DNA fragmentation detected using TUNEL assay confirmed apoptosis. Cleaved/activated-caspase-8 and -caspase-3 upregulation along with mitochondrial translocation of bax protein and release of cytochrome-c were consistent with the activation of both the extrinsic and intrinsic caspase-dependent programmed cell death pathways. The prominent release of stress-associated Hsp70, calreticulin and HMGB1 proteins, relevant to DAMP signaling, was accompanied by the significant tumor infiltration by S100 positive antigen presenting dendritic cells and CD3 positive T-cells with only scant FoxP3 positive regulatory T-cells. In addition, mEHT combined with a chlorogenic acid rich T-cell promoting agent induced significant cell death both in the treated and the untreated contralateral tumors indicating a systemic anti-tumor effect.Conclusions: mEHT induced caspase-dependent programmed cell death and the release of stress associated DAMP proteins in colorectal cancer allografts can provoke major immune cell infiltration. Accumulating antigen presenting dendritic cells and T-cells are likely to contribute to the ongoing tumor destruction by an immunogenic cell death mechanism both locally and through systemic effect at distant tumor sites.
Microsporidiosis (nosema disease) of the European honeybee (Apis mellifera L.) is present in bee colonies worldwide. Until recently, Nosema apis had been regarded as the causative agent of the disease, which may have many negative effects on the colony and cause heavy economic losses in apicultures. Another microsporidium species, Nosema ceranae, was reported to infest the Asian honeybee (Apis ceranae), but both honeybee species are susceptible to both microsporidia. In the European honeybee N. ceranae was first detected in Spain in the year 2006. As it is difficult to distinguish N. ceranae and N. apis morphologically, a rapid and accurate assay has been developed to differentiate N. apis and N. ceranae based on polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the partial large subunit ribosomal RNA. The assay was tested on 38 Nosema-infested bee samples, which were collected from geographically distant Hungarian bee colonies representing all regions of the country. Only one sample contained N. apis, and in the other 37 samples N. ceranae was detected, which indicates the dominance of N. ceranae in Hungarian apiaries. This is the first report on the presence of N. ceranae in Hungary.
Heat stress is one of the most important issues in broiler flocks impairing animal health and productivity. On a cellular level, excess heat exposure can trigger heat shock response acting for the restoration of cell homeostasis by several mechanisms, such as affecting heat shock protein synthesis, redox homeostasis and pro-inflammatory cytokine production. The major aim of this study was to establish a novel avian hepatocyte—nonparenchymal cell co-culture as a model for investigating the cellular effects of heat stress and its interaction with inflammation in chicken liver. Cell fractions were isolated by differential centrifugation from a freshly perfused chicken liver, and hepatocyte mono-cultures as well as hepatocyte–nonparenchymal cell co-cultures (with cell ratio 6:1, hepatocytes to nonparenchymal cells, mimicking a milder hepatic inflammation) were prepared. Isolated and cultured cells were characterized by flow cytometry and immunocytochemistry applying hepatocyte- and macrophage-specific antibodies. Confluent cell cultures were exposed to 43 °C temperature for 1 or 2 h, while controls were cultured at 38.5 °C. The metabolic activity, LDH enzyme activity, reactive oxygen species (H2O2) production, extracellular concentration of heat shock protein 70 (HSP70), and that of the pro-inflammatory cytokines interleukin (IL-)6 and IL-8 were assessed. Shorter heat stress applied for 1 h could strongly influence liver cell function by significantly increasing catabolic metabolism and extracellular H2O2 release, and by significantly decreasing HSP70, IL-6, and IL-8 production on both cell culture models. However, all these alterations were restored after 2 h heat exposure, indicating a fast recovery of liver cells. Hepatocyte mono-cultures and hepatocyte—nonparenchymal cell co-cultures responded to heat stress in a similar manner, but the higher metabolic rate of co-cultured cells may have contributed to a better capability of inflamed liver cells for accommodation to stress conditions. In conclusion, the established new primary cell culture models provide suitable tools for studying the hepatic inflammatory and stress response. The results of this study highlight the impact of short-term heat stress on the liver in chickens, underline the mediatory role of oxidative stress in acute stress response, and suggest a fast cellular adaptation potential in liver cells.
1Phylogenetic analysis of 22 Black queen cell virus (BQCV) genotypes collected from 2 honeybee colonies in Poland, Austria and Hungary was performed on a partial helicase 3 enzyme coding region (ORF1) and on a partial structural polypeptide coding region (ORF2). 4While the phylogeny based on the ORF2 region showed -with the exception of one strain 5 from Poland -clustering of the genotypes corresponding to their geographic origin, the 6 ORF1-based tree exhibited a completely different distribution of the Polish strains: three of 7 them clustered within a branch clearly separated from all other central European BQCVs, 8 while four other Polish strains remained well within the central European BQCV genotypes. 9In order to investigate this discrepancy in more detail, the nearly complete genome sequences 10 of the 3 differing Polish strains were determined, together with one Hungarian sample. The 11 sequences were aligned to each other and to the reference strain from South-Africa. 12Comparison of the different genome regions revealed that the 5'-UTR and the intergenic 13 regions of the BQCV genome are highly conserved with longer homologous sections. ORF1 14 (non-structural protein coding region) was found more variable compared to ORF2 (structural 15 protein coding region). The 5'-proximal third of ORF1 was particularly variable and contained 16 several deletions / insertions. The sudden changes in the similarity levels of BQCV strains in 17 different genomic regions are indicative of preceding recombination events.
The effect of oxidative stress on barrier integrity and localization of transmembrane serine proteinase 2 (TMPRSS2) were studied using porcine epithelial IPEC-J2 cells on membrane inserts. Increased paracellular permeability of FITC-dextran 4 kDa (fluorescence intensity 43,508 ± 2,391 versus 3,550 ± 759) and that of gentamicin (3.41 ± 0.06 % increase to controls) were measured parallel with the reduced transepithelial electrical resistance (23.3 ± 4.06 % decrease) of cell layers 6 h after 1 h 1 mM H2O2 treatment. The immunohistochemical localization of adherens junctional β-catenin was not affected by reactive oxygen species (ROS) up to 4 mM H2O2. Peroxide-triggered enhanced paracellular permeability of IPEC-J2 cell layer was accompanied by predominantly cytoplasmic occurrence of TMPRSS2 embedded in cell membrane under physiological conditions. These results support that ROS can influence paracellular gate opening via multifaceted mode of action without involvement of β-catenin redistribution in adherens junction. Altered distribution pattern of TMPRSS2 and relocalized transmembrane serine protease activity may contribute to weakening of epithelial barrier integrity under acute oxidative stress.
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