Novel Gluconobacter oxydans strains selected from Kombucha with potential postbiotic activity.

Gastric and colorectal cancer are among the most frequently diagnosed malignancies of the gastrointestinal tract. Searching for methods of therapy that complements treatment or has a preventive effect is desirable. Bacterial metabolites safe for human health, which have postbiotic effect, are of interest recently. The study aimed to preliminary assessment of the safety, antimicrobial, and anti-cancer activity of cell-free metabolites of Gluconobacter oxydans strains isolated from Kombucha beverages as an example of the potential postbiotic activity of acetic acid bacteria (AAB). The study material consisted of five AAB strains of Kombucha origin and three human cell lines (gastric adenoma-AGS, colorectal adenoma-HT-29, and healthy cells derived from the endothelium of the human umbilical vein-HUVEC). Results of the study confirms the health safety and functional properties of selected AAB strains, including their potential postbiotic properties. The best potential anticancer activity of the AAB cell-free supernatants was demonstrated against AGS gastric adenoma cells. The conducted research proves the postbiotic potential of selected acetic acid bacteria, especially the KNS30 strain. KEY POINTS: •The beneficial and application properties of acetic acid bacteria are poorly studied. •Gluconobacter oxydans from Kombucha show a postbiotic activity. •The best anticancer activity of the G. oxydans showed against gastric adenoma.

Ectromelia Virus Affects the Formation and Spatial Organization of Adhesive Structures in Murine Dendritic Cells In Vitro.

Ectromelia virus (ECTV) is a causative agent of mousepox. It provides a suitable model for studying the immunobiology of orthopoxviruses, including their interaction with the host cell cytoskeleton. As professional antigen-presenting cells, dendritic cells (DCs) control the pericellular environment, capture antigens, and present them to T lymphocytes after migration to secondary lymphoid organs. Migration of immature DCs is possible due to the presence of specialized adhesion structures, such as podosomes or focal adhesions (FAs). Since assembly and disassembly of adhesive structures are highly associated with DCs' immunoregulatory and migratory functions, we evaluated how ECTV infection targets podosomes and FAs' organization and formation in natural-host bone marrow-derived DCs (BMDC). We found that ECTV induces a rapid dissolution of podosomes at the early stages of infection, accompanied by the development of larger and wider FAs than in uninfected control cells. At later stages of infection, FAs were predominantly observed in long cellular extensions, formed extensively by infected cells. Dissolution of podosomes in ECTV-infected BMDCs was not associated with maturation and increased 2D cell migration in a wound healing assay; however, accelerated transwell migration of ECTV-infected cells towards supernatants derived from LPS-conditioned BMDCs was observed. We suggest that ECTV-induced changes in the spatial organization of adhesive structures in DCs may alter the adhesiveness/migration of DCs during some conditions, e.g., inflammation.

Adaptation of mitochondrial network dynamics and velocity of mitochondrial movement to chronic stress present in fibroblasts derived from patients with sporadic form of Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases. Only 10% of all cases are familial form, the remaining 90% are sporadic form with unknown genetic background. The etiology of sporadic AD is still not fully understood. Pathogenesis and pathobiology of this disease are limited due to the limited number of experimental models. We used primary culture of fibroblasts derived from patients diagnosed with sporadic form of AD for investigation of dynamic properties of mitochondria, including fission-fusion process and localization of mitochondria within the cell. We observed differences in mitochondrial network organization with decreased mitochondrial transport velocity, and a drop in the frequency of fusion-fission events. These studies show how mitochondrial dynamics adapt to the conditions of long-term mitochondrial stress that prevails in cells of sporadic form of AD.

Comprehensive Molecular Dissection of Dermatophilus congolensis Genome and First Observation of tet(Z) Tetracycline Resistance.

Dermatophilus congolensis is a bacterial pathogen mostly of ruminant livestock in the tropics/subtropics and certain temperate climate areas. It causes dermatophilosis, a skin disease that threatens food security by lowering animal productivity and compromising animal health and welfare. Since it is a prevalent infection in ruminants, dermatophilosis warrants more research. There is limited understanding of its pathogenicity, and as such, there is no registered vaccine against D. congolensis. To better understanding the genomics of D. congolensis, the primary aim of this work was to investigate this bacterium using whole-genome sequencing and bioinformatic analysis. D. congolensis is a high GC member of the Actinobacteria and encodes approximately 2527 genes. It has an open pan-genome, contains many potential virulence factors, secondary metabolites and encodes at least 23 housekeeping genes associated with antimicrobial susceptibility mechanisms and some isolates have an acquired antimicrobial resistance gene. Our isolates contain a single CRISPR array Cas type IE with classical 8 Cas genes. Although the isolates originate from the same geographical location there is some genomic diversity among them. In conclusion, we present the first detailed genomic study on D. congolensis, including the first observation of tet(Z), a tetracycline resistance-conferring gene.

Human mesenchymal stem cell (hMSC) differentiation towards cardiac cells using a new microbioanalytical method.

Stem cells (SCs) are more and more often applied in tissue engineering and cell therapies, e.g. in regenerative medicine. Standard methods of SC differentiation are time consuming and ineffective. Therefore, new bioanalytical methods (i.e. Lab-on-a-Chip systems) are develop to improve such type of studies. Although, microtechnology is a rapidly growing research area, there are so far not too many works which present SC differentiation into cardiomyocytes in the microsystems. Therefore, we present new microbioanalytical method of SC differentiation towards cardiac cells using a newly developed digitally controlled microdispenser integrated with a Heart-on-a-chip system. Seven-day culture of human mesenchymal stem cells (hMSCs) and their differentiation using biochemical factors such as 5-AZA (2 µM, 24 h) and VEGF (20 ng ml-1, 72 h) were investigated in the microsystem which was automatically operated using smartphone software. hMSC differentiation into the cardiac cells was confirmed using immunostaining of cardiac markers (α-actinin and troponin T). The usage of the microsystem allowed shortening the time of hMSC differentiation in comparison to macroscale method. We showed that the microsystem, in which the in vivo microenvironment is mimicked and dynamic conditions are provided by a microdispenser, favorably affect hMSC differentiation towards cardiac cells. Based on the presented research we can conclude that the developed digitally controlled microsystem could be successfully utilized as a new microbioanalytical method for stem cells differentiation and analysis of their function under dynamic conditions. In the future, this could be a helpful tool for scientists working on regenerative medicine.

Deficiency of Selected Cathepsins Does Not Affect the Inhibitory Action of ECTV on Immune Properties of Dendritic Cells.

Ectromelia virus (ECTV), an orthopoxvirus, undergoes productive replication in conventional dendritic cells (cDCs), resulting in the inhibition of their innate and adaptive immune functions. ECTV replication rate in cDCs is increased due to downregulation of the expression of cathepsins - cystein proteases that orchestrate several steps during DC maturation. Therefore, this study was aimed to determine if downregulation of cathepsins, such as B, L or S, disrupts cDC capacity to induce activating signals in T cells or whether infection of cDCs with ECTV further weakens their functions as antigen-presenting cells. Our results showed that cDCs treated with siRNA against cathepsin B, L and S synthesize similar amounts of pro-inflammatory cytokines and exhibit comparable ability to mature and stimulate alloreactive CD4+ T cells, as untreated wild type (WT) cells. Moreover, ECTV inhibitory effect on cDC innate and adaptive immune functions, observed especially after LPS treatment, was comparable in both cathepsin-silenced and WT cells. Taken together, the absence of cathepsins B, L and S has minimal, if any, impact on the inhibitory effect of ECTV on cDC immune functions. We assume that the virus-mediated inhibition of cathepsin expression in cDCs represents more a survival mechanism than an immune evasion strategy.

Bacterial and viral pathogen-associated molecular patterns induce divergent early transcriptomic landscapes in a bovine macrophage cell line.

BACKGROUND: Pathogens stimulate immune functions of macrophages. Macrophages are a key sentinel cell regulating the response to pathogenic ligands and orchestrating the direction of the immune response. Our study aimed at investigating the early transcriptomic changes of bovine macrophages (Bomacs) in response to stimulation with CpG DNA or polyI:C, representing bacterial and viral ligands respectively, and performed transcriptomics by RNA sequencing (RNASeq). KEGG, GO and IPA analytical tools were used to reconstruct pathways, networks and to map out molecular and cellular functions of differentially expressed genes (DE) in stimulated cells. RESULTS: A one-way ANOVA analysis of RNASeq data revealed significant differences between the CpG DNA and polyI:C-stimulated Bomac. Of the 13,740 genes mapped to the bovine genome, 2245 had p-value ≤0.05, deemed as DE. At 6 h post stimulation of Bomac, poly(I:C) induced a very different transcriptomic profile from that induced by CpG DNA. Whereas, 347 genes were upregulated and 210 downregulated in response to CpG DNA, poly(I:C) upregulated 761 genes and downregulated 414 genes. The topmost DE genes in poly(I:C)-stimulated cells had thousand-fold changes with highly significant p-values, whereas in CpG DNA stimulated cells had 2-5-fold changes with less stringent p-values. The highest DE genes in both stimulations belonged to the TNF superfamily, TNFSF18 (CpG) and TNFSF10 (poly(I:C)) and in both cases the lowest downregulated gene was CYP1A1. CpG DNA highly induced canonical pathways that are unrelated to immune response in Bomac. CpG DNA influenced expression of genes involved in molecular and cellular functions in free radical scavenging. By contrast, poly(I:C) highly induced exclusively canonical pathways directly related to antiviral immune functions mediated by interferon signalling genes. The transcriptomic profile after poly(I:C)-stimulation was consistent with induction of TLR3 signalling. CONCLUSION: CpG DNA and poly(I:C) induce different early transcriptional landscapes in Bomac, but each is suited to a specific function of macrophages during interaction with pathogens. Poly(I:C) influenced antiviral response genes, whereas CpG DNA influenced genes important for phagocytic processes. Poly(I:C) was more potent in setting the inflammatory landscape desirable for an efficient immune response against virus infection.

Ectromelia virus suppresses expression of cathepsins and cystatins in conventional dendritic cells to efficiently execute the replication process.

BACKGROUND: Cathepsins are a group of endosomal proteases present in many cells including dendritic cells (DCs). The activity of cathepsins is regulated by their endogenous inhibitors - cystatins. Cathepsins are crucial to antigen processing during viral and bacterial infections, and as such are a prerequisite to antigen presentation in the context of major histocompatibility complex class I and II molecules. Due to the involvement of DCs in both innate and adaptive immune responses, and the quest to understand the impact of poxvirus infection on host cells, we investigated the influence of ectromelia virus (ECTV) infection on cathepsin and cystatin levels in murine conventional DCs (cDCs). ECTV is a poxvirus that has evolved many mechanisms to avoid host immune response and is able to replicate productively in DCs. RESULTS: Our results showed that ECTV-infection of JAWS II DCs and primary murine GM-CSF-derived bone marrow cells down-regulated both mRNA and protein of cathepsin B, L and S, and cystatin B and C, particularly during the later stages of infection. Moreover, the activity of cathepsin B, L and S was confirmed to be diminished especially at later stages of infection in JAWS II cells. Consequently, ECTV-infected DCs had diminished ability to endocytose and process a soluble antigen. Close examination of cellular protein distribution showed that beginning from early stages of infection, the remnants of cathepsin L and cystatin B co-localized and partially co-localized with viral replication centers (viral factories), respectively. Moreover, viral yield increased in cDCs treated with siRNA against cathepsin B, L or S and subsequently infected with ECTV. CONCLUSIONS: Taken together, our results indicate that infection of cDCs with ECTV suppresses cathepsins and cystatins, and alters their cellular distribution which impairs the cDC function. We propose this as an additional viral strategy to escape immune responses, enabling the virus to replicate effectively in infected cells.

Ectromelia virus induces tubulin cytoskeletal rearrangement in immune cells accompanied by a loss of the microtubule organizing center and increased α-tubulin acetylation.

Ectromelia virus (ECTV) is an orthopoxvirus that productively replicates in dendritic cells (DCs), but its influence on the microtubule (MT) cytoskeleton in DCs is not known. Here, we show that ECTV infection of primary murine granulocyte-macrophage colony stimulating factor-derived bone marrow cells (GM-BM) downregulates numerous genes engaged in MT cytoskeleton organization and dynamics. In infected cells, the MT cytoskeleton undergoes dramatic rearrangement and relaxation, accompanied by disappearance of the microtubule organizing centre (MTOC) and increased acetylation and stabilization of MTs, which are exploited by progeny virions for intracellular transport. This indicates a strong ability of ECTV to subvert the MT cytoskeleton of highly specialized immune cells.

ECTV Abolishes the Ability of GM-BM Cells to Stimulate Allogeneic CD4 T Cells in a Mouse Strain-Independent Manner.

Ectromelia virus (ECTV) is the etiological agent of mousepox, an acute and systemic disease with high mortality rates in susceptible strains of mice. Resistance and susceptibility to mousepox are triggered by the dichotomous T-helper (Th) immune response generated in infected animals, with strong protective Th1 or nonprotective Th2 profile, respectively. Th1/Th2 balance is influenced by dendritic cells (DCs), which were shown to differ in their ability to polarize naïve CD4+ T cells in different mouse strains. Therefore, we have studied the inner-strain differences in the ability of conventional DCs (cDCs), generated from resistant (C57BL/6) and susceptible (BALB/c) mice, to stimulate proliferation and activation of Th cells upon ECTV infection. We found that ECTV infection of GM-CSF-derived bone marrow (GM-BM) cells, composed of cDCs and macrophages, affected initiation of allogeneic CD4+ T cells proliferation in a mouse strain-independent manner. Moreover, infected GM-BM cells from both mouse strains failed to induce and even inhibited the production of Th1 (IFN-γ and IL-2), Th2 (IL-4 and IL-10) and Th17 (IL-17A) cytokines by allogeneic CD4+ T cells. These results indicate that in in vitro conditions ECTV compromises the ability of cDCs to initiate/polarize adaptive antiviral immune response independently of the host strain resistance/susceptibility to lethal infection.

Long actin-based cellular protrusions as novel evidence of the cytopathic effect induced in immune cells infected by the ectromelia virus.

The aim of the study was to evaluate the influence of ectromelia virus (ECTV) infection on actin cytoskeleton rearrangement in immune cells, such as macrophages and dendritic cells (DCs). Using scanning electron and fluorescence microscopy analysis we observed the presence of long actin-based cellular extensions, formed by both types of immune cells at later stages of infection with ECTV. Such extensions contained straight tubulin filaments and numerous punctuate mitochondria. Moreover, these long cellular projections extended to a certain length and formed convex structures termed "cytoplasmic packets". These structures contained numerous viral particles and presumably were sites of progeny virions' release via budding. Further, discrete mitochondria and separated tubulin filaments that formed a scaffold for accumulated mitochondria were visible within cytoplasmic packets. ECTV-induced long actin-based protrusions resemble "cytoplasmic corridors" and probably participate in virus dissemination. Our data demonstrate the incredible capacity for adaptation of ECTV to its natural host immune cells, in which it can survive, replicate and induce effective mechanisms for viral spread and dissemination.

[MAVS protein and its interactions with hepatitis A, B and C viruses]. / Bialko MAVS i jego interakcje z wirusami zapalenia watroby typu A, B i C.

Mitochondrial antiviral signaling protein (MAVS) transmits activation signal of type I interferon (IFN) gene transcription in the molecular intracellular pathway, which depends on the protein encoded by retinoic acid inducible gene I (RIG-I) or melanoma differentiation-associated protein-5 (MDA-5). MAVS, as a signal molecule, performs an essential function in the development of an antiviral immune response. The molecule of MAVS consists of two domains: the N-terminal domain and the C-terminal domain. The N-terminal end of MAVS contains the caspase activation and recruitment domain (CARD). CARD is responsible for MAVS interaction with RIG-I and MDA-5, which act as cytosolic sensors detecting foreign viral genetic material in the host cell. After binding to viral RNA, RIG-I or MDA-5 activates MAVS and transmits the signal of IFN type I gene expression. The C-terminal transmembrane domain (TM) of MAVS anchors the protein to the outer mitochondrial membrane. In this paper interactions between MAVS and hepatitis virus type A (HAV), type B (HBV) and type C (HCV) are presented. Mechanisms of indirect activation of MAVS by viral DNA and RNA, as well as the strategies of HAV, HBV and HCV for blocking of the intracellular signaling pathway at the level of MAVS, are described.

Strategies of NF-κB signaling modulation by ectromelia virus in BALB/3T3 murine fibroblasts.

Nuclear factor κB (NF-κB) is a pleiotropic transcription factor that regulates the expression of immune response genes. NF-κB signaling can be disrupted by pathogens that prevent host immune response. In this work, we examined the influence of ectromelia (mousepox) virus (ECTV) on NF-κB signaling in murine BALB/3T3 fibroblasts. Activation of NF-κB via tumor necrosis factor (TNF) receptor 1 (TNFR1) in these cells induces proinflammatory cytokine secretion. We show that ECTV does not recruit NF-κB to viral factories or induce NF-κB nuclear translocation in BALB/3T3 cells. Additionally, ECTV counteracts TNF-α-induced p65 NF-κB nuclear translocation during the course of infection. Inhibition of TNF-α-induced p65 nuclear translocation was also observed in neighboring cells that underwent fusion with ECTV-infected cells. ECTV inhibits the key step of NF-κB activation, i.e. Ser32 phosphorylation and degradation of inhibitor κBα (IκBα) induced by TNF-α. We also observed that ECTV prevents TNF-α-induced Ser536 of p65 phosphorylation in BALB/3T3 cells. Studying TNFR1 signaling provides information about regulation of inflammatory response and cell survival. Unraveling poxviral immunomodulatory strategies may be helpful in drug target identification as well as in vaccine development.

Modulation of proinflammatory NF-κB signaling by ectromelia virus in RAW 264.7 murine macrophages.

Macrophages are antigen-presenting cells (APCs) that play a crucial role in the innate immune response and may be involved in both clearance and spread of viruses. Stimulation of macrophages via Toll-like receptors (TLRs) results in activation of nuclear factor κB (NF-κB) and synthesis of proinflammatory cytokines. In this work, we show modulation of proinflammatory NF-κB signaling by a member of the family Poxviridae, genus Orthopoxvirus--ectromelia virus (ECTV)--in RAW 264.7 murine macrophages. ECTV interfered with p65 NF-κB nuclear translocation induced by TLR ligands such as lipopolysaccharide (LPS) (TLR4), polyinosinic-polycytidylic acid (poly(I:C)) (TLR3) and diacylated lipopeptide Pam2CSK4 (TLR2/6). We observed that ECTV modulates phosphorylation of Ser32 of inhibitor of κB (IκBα) and Ser536 of p65. Interference of ECTV with TLR signaling pathways implied that proinflammatory cytokine synthesis was inhibited. Our studies provide new insights into the strategies of proinflammatory signaling modulation by orthopoxviruses during their replication cycle in immune cells. Understanding important immune interactions between viral pathogens and APCs might contribute to the identification of drug targets and the development of vaccines.

[Participation of heat shock proteins in modulation of NF-кB transcription factor activation during bacterial infections]. / Udzial bialek szoku cieplnego w modulacji aktywacji czynnika transkrypcyjnego NF-кB podczas zakazen bakteryjnych.

Nuclear factor kappa-light-chain enhancer of activated B-cells (NF-кB) is a pleiotropic transcription factor, which regulates processes of immune response and inflammation. NF-кB can undergo activation as a result of bacterial infections via Toll-like receptors (TLR), which recognize pathogen-associated molecular patterns (PAMP), such as lipopolysaccharides (LPS). Stimulation of the cells results in phosphorylation of inhibitor кB (IкB) and the translocation of NF-кB to the nucleus, where the transcription of genes encoding molecules, such as proinflammatory cytokines and chemokines takes place. Activation of NF-кB undergoes modulation upon heat shock, which induces the expression of heat shock proteins (HSP). NF-кB, in turn, is involved in the regulation of transcription of genes encoding HSP, while members of HSP family are modulators of NF-кB activation, which occurs as a result bacterial infections and leads to the development of inflammation. HSP90 is a major chaperone, which is associated with IкB kinase (IKK) subunits. HSP90 inhibitors enable dissociation of such complexes, thus blocking NF-кB and inflammatory process during bacterial infections. HSP72 and HSP70, in turn, modulate the expression of NF-кB controlled genes during sepsis and play a protective role, whereas exogenous HSP70 may enhance the inflammatory response. Bacterial HSP, such as HSP60 of Chlamydia pneumophila and Helicobacter pylori, or GroL of Porphyromonas gingivalis, as well as HSP65 and HSP70 of Mycobacterium tuberculosis and DnaK of Francisella tularensis activate NF-κB and inflammation. Knowledge of these interactions is extremely helpful in the development of therapeutic strategies.

[Th17 lymphocytes in bacterial infections]. / Limfocyty Th17 w zakazeniach bakteryjnycH.

Th17 cells are a relatively newly discovered subpopulation of helper CD4+ T lymphocytes. It has been shown that these cells may contribute to tissue damage during certain inflammatory and autoimmune diseases and also play an important role in antitumor and antimicrobial, particularly antibacterial, immunity. Bacteria stimulate the Th17 response through several Toll-like (TLR), NOD-like (NLR) and C-type lectin (CLR) receptors. When activated, Th17 lymphocytes produce several cytokines, mainly interleukin (IL)-17 and chemokines, that further attract and activate phagocytes to mediate bacterial clearance. Thus Th17 cells contribute to induction of host protective immunity, particularly against extracellular bacterial pathogens: Staphylococcus aureus, Streptococcus pneumoniae and Klebsiella pneumoniae. Furthermore, numerous studies indicate the importance of Th17 lymphocytes in immunity against intracellular bacteria such as Francisella tularensis and Chlamydia muridarum. In this case, the protective immune response is mediated mainly through stimulation of local dendritic cell (DC) function for establishing a Th1 immune response, indispensable for controlling intracellular infectious agents. However, deregulation of the Th17/IL17 response during bacterial infections may lead to profound pathologies. As a result, Th17 cells participate in chronic inflammatory diseases, leading to tissue destruction and favoring tumor development. This article summarizes current understanding of the bacteriainduced Th17 response in the context of the protective immune response and immunopathology.

Modulation of NF-кB transcription factor activation by Molluscum contagiosum virus proteins.

Molluscum contagiosum virus is a human and animal dermatotropic pathogen, which causes a severe disease in immunocompromised individuals. MCV belongs to the Poxviridae family whose members exert immunomodulatory effects on the host antiviral response. Poxviruses interfere with cell signaling pathways that lead to the activation of nuclear factor кB, a pleiotropic transcription factor which is crucial for regulation of the immune response, the cell cycle and apoptosis. In resting cells, NF-κB is present in the cytoplasm, where it is associated with inhibitor κB. Upon stimulation by activators, such as proinflammatory cytokines and bacterial or viral products, the inhibitory protein undergoes phosphorylation and proteasomal degradation. NF-κB, in turn, translocates to the nucleus, where it regulates the transcription of various genes that are essential for processes mentioned above. Since poxviruses replicate exclusively in the cell cytoplasm, NF-кB became a good target for poxviral immunomodulation. MCV encodes various proteins which interfere with the signaling pathways that lead to the activation of NF-κB. Ligand inhibitor encoded by MCV, MC54, binds interleukin-18 and inhibits interferon-γ production. Other MCV proteins, MC159 and MC160, belong to intracellular inhibitors of NF-κB and are members of viral FLICE-inhibitory proteins (vFLIPs). MC159 protein encoded by MCV was shown to inhibit apoptosis of virus-infected cells. Such interactions serve immune evasion and are responsible for the persistence of MCV.

[Cooperation between heat shock proteins in organizing of proteins spatial structure]. / Wspóldzialanie bialek szoku cieplnego w organizowaniu struktury przestrzennej bialek.

Heat shock proteins (Hsps) are a class of proteins with highly conserved amino acid sequences. They are widespread in nature; they are found in archeons, true bacteria and eukaryotic organisms. Hsps from various families, commonly interact to execute essential cellular tasks, such as molecular regulation of newly synthesized protein-folding or restoration of the appropriate conformation of denatured and aggregated proteins. In this review we discuss mechanisms of spatial organization of protein structure mediated by Hsp10, Hsp40, Hsp60, Hsp70, Hsp104 (Hsp100) and Hsp110. Interactions between Hsps of different molecular weights are described.

Lack of in vitro effect of aglepristone on IFN-γ and IL-4 production by resting and mitogen-activated T cells of luteal bitches.

BACKGROUND: Aglepristone (RU534) is an antiprogestin used for pregnancy termination, parturition induction and conservative pyometra treatment in bitches. Its molecular structure is similar to mifepristone, an antiprogestin used in human medicine. Mifepristone has been shown to suppress proliferation and cytokine production by T cells, whereas the effect of aglepristone on T cell function remains elusive. The purpose of this project was to investigate the in vitro influence of RU534 on IFN-γ and IL-4 synthesis by peripheral blood T cells isolated from healthy bitches (N = 16) in luteal phase. The peripheral blood mononuclear cells (PBMCs) were incubated with three different dosages of aglepristone, or dimethyl sulfoxide (DMSO), with or without mitogen. The production of cytokines by resting or mitogen-activated T cells was determined by intercellular staining and flow cytometry analysis or ELISA assay, respectively. RESULTS: Our results showed no statistically significant differences in the percentage of IFN-γ and IL-4-synthesizing CD4+ or CD8+ resting T cells between untreated and aglepristone-treated cells at 24 and 48 hours post treatment. Moreover, mitogen-activated PBMCs treated with RU534 displayed similar concentration of IFN-γ and IL-4 in culture supernatants to those observed in mitogen-activated DMSO-treated PBMCs. Presented results indicate that administration of aglepristone for 48 hours has no influence on IFN-γ and IL-4 synthesis by resting and mitogen-activated T cells isolated from diestral bitches. CONCLUSIONS: We conclude that antiprogestins may differentially affect T cell function depending on the animal species in which they are applied.

Orthopoxvirus Zoonoses-Do We Still Remember and Are Ready to Fight?

The eradication of smallpox was an enormous achievement due to the global vaccination program launched by World Health Organization. The cessation of the vaccination program led to steadily declining herd immunity against smallpox, causing a health emergency of global concern. The smallpox vaccines induced strong, humoral, and cell-mediated immune responses, protecting for decades after immunization, not only against smallpox but also against other zoonotic orthopoxviruses that now represent a significant threat to public health. Here we review the major aspects regarding orthopoxviruses' zoonotic infections, factors responsible for viral transmissions, as well as the emerging problem of the increased number of monkeypox cases recently reported. The development of prophylactic measures against poxvirus infections, especially the current threat caused by the monkeypox virus, requires a profound understanding of poxvirus immunobiology. The utilization of animal and cell line models has provided good insight into host antiviral defenses as well as orthopoxvirus evasion mechanisms. To survive within a host, orthopoxviruses encode a large number of proteins that subvert inflammatory and immune pathways. The circumvention of viral evasion strategies and the enhancement of major host defenses are key in designing novel, safer vaccines, and should become the targets of antiviral therapies in treating poxvirus infections.