Identification and functional characterization of Toll-like receptor 2-1 in geese

Understanding eco-immunology of bacterial zoonoses and alternative therapeutics toward "One Health"

The current review identifies key bacterial zoonoses, the understanding of comparative immunology, evolutionary trade-offs between emerging bacterial pathogens and their dynamics on both arms of immunity. The several gaps in the literature limit our understanding of spread of prominent bacterial zoonotic diseases and the host-pathogen interactions that may change in response to environmental and social factors. Gaining a more comprehensive understanding of how anthropogenic activities affects the spread of emerging zoonotic diseases, is essential for predicting and mitigating future disease emergence through fine-tuning of surveillance and control measures with respect to different pathogens. This review highlights the urgent need to increase understanding of the comparative immunity of animal reservoirs, design of vaccines according to the homology in host-pathogen interactions, and the alternative strategies to counter the risk of bacterial pathogenic spillover to humans with eventual spread of zoonotic diseases.

Redox Homeostasis in Poultry: Regulatory Roles of NF-κB

Redox biology is a very quickly developing area of modern biological sciences, and roles of redox homeostasis in health and disease have recently received tremendous attention. There are a range of redox pairs in the cells/tissues responsible for redox homeostasis maintenance/regulation. In general, all redox elements are interconnected and regulated by various means, including antioxidant and vitagene networks. The redox status is responsible for maintenance of cell signaling and cell stress adaptation. Physiological roles of redox homeostasis maintenance in avian species, including poultry, have received limited attention and are poorly characterized. However, for the last 5 years, this topic attracted much attention, and a range of publications covered some related aspects. In fact, transcription factor Nrf2 was shown to be a master regulator of antioxidant defenses via activation of various vitagenes and other protective molecules to maintain redox homeostasis in cells/tissues. It was shown that Nrf2 is closely related to another transcription factor, namely, NF-κB, responsible for control of inflammation; however, its roles in poultry have not yet been characterized. Therefore, the aim of this review is to describe a current view on NF-κB functioning in poultry with a specific emphasis to its nutritional modulation under various stress conditions. In particular, on the one hand, it has been shown that, in many stress conditions in poultry, NF-κB activation can lead to increased synthesis of proinflammatory cytokines leading to systemic inflammation. On the other hand, there are a range of nutrients/supplements that can downregulate NF-κB and decrease the negative consequences of stress-related disturbances in redox homeostasis. In general, vitagene-NF-κB interactions in relation to redox balance homeostasis, immunity, and gut health in poultry production await further research.

Mycoplasmas-Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation

Mycoplasmas are the smallest and simplest self-replicating prokaryotes. Located everywhere in nature, they are widespread as parasites of humans, mammals, reptiles, fish, arthropods, and plants. They usually exhibiting organ and tissue specificity. Mycoplasmas belong to the class named Mollicutes (mollis = soft and cutis = skin, in Latin), and their small size and absence of a cell wall contribute to distinguish them from other bacteria. Mycoplasma species are found both outside the cells as membrane surface parasites and inside the cells, where they become intracellular residents as "silent parasites". In humans, some Mycoplasma species are found as commensal inhabitants, while others have a significant impact on the cellular metabolism and physiology. Mollicutes lack typical bacterial PAMPs (e.g., lipoteichoic acid, flagellin, and some lipopolysaccharides) and consequently the exact molecular mechanisms of Mycoplasmas' recognition by the cells of the immune system is the subjects of several researches for its pathogenic implications. It is well known that several strains of Mycoplasma suppress the transcriptional activity of p53, resulting in reduced apoptosis of damaged cells. In addition, some Mycoplasmas were reported to have oncogenic potential since they demonstrated not just accumulation of abnormalities but also phenotypic changes of the cells. Aim of this review is to provide an update of the current literature that implicates Mycoplasmas in triggering inflammation and altering critical cellular pathways, thus providing a better insight into potential mechanisms of cellular transformation.

Effects of Mycoplasmas on the Host Cell Signaling Pathways

Mycoplasmas are the smallest free-living organisms. Reduced sizes of their genomes put constraints on the ability of these bacteria to live autonomously and make them highly dependent on the nutrients produced by host cells. Importantly, at the organism level, mycoplasmal infections may cause pathological changes to the host, including cancer and severe immunological reactions. At the molecular level, mycoplasmas often activate the NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) inflammatory response and concomitantly inhibit the p53-mediated response, which normally triggers the cell cycle and apoptosis. Thus, mycoplasmal infections may be considered as cancer-associated factors. At the same time, mycoplasmas through their membrane lipoproteins (LAMPs) along with lipoprotein derivatives (lipopeptide MALP-2, macrophage-activating lipopeptide-2) are able to modulate anti-inflammatory responses via nuclear translocation and activation of Nrf2 (the nuclear factor-E2-related anti-inflammatory transcription factor 2). Thus, interactions between mycoplasmas and host cells are multifaceted and depend on the cellular context. In this review, we summarize the current information on the role of mycoplasmas in affecting the host’s intracellular signaling mediated by the interactions between transcriptional factors p53, Nrf2, and NF-κB. A better understanding of the mechanisms underlying pathologic processes associated with reprogramming eukaryotic cells that arise during the mycoplasma-host cell interaction should facilitate the development of new therapeutic approaches to treat oncogenic and inflammatory processes.

Mycoplasma anserisalpingitidis sp. nov., isolated from European domestic geese (Anser anser domesticus) with reproductive pathology

In 1983, Mycoplasma sp. strain 1220 was isolated in Hungary from the phallus lymph of a gander with phallus inflammation. Between 1983 and 2017, Mycoplasma sp. 1220 was also identified and isolated from the respiratory tract, liver, ovary, testis, peritoneum and cloaca of diseased geese in several countries. Seventeen studied strains produced acid from glucose and fructose but did not hydrolyse arginine or urea, and all grew under aerobic, microaerophilic and anaerobic conditions at 35 to 37 ˚C in either SP4 or pleuropneumonia-like organism medium supplemented with glucose and serum. Colonies on agar showed a typical fried-egg appearance and transmission electron microscopy revealed a typical mycoplasma cellular morphology. Molecular characterization included analysis of the following genetic loci: 16S rRNA, 23S rRNA, 16S-23S rRNA ITS, rpoB, rpoC, rpoD, uvrA, parC, topA, dnaE, fusA and pyk. The genome was sequenced for type strain 1220^T. The 16S rRNA gene sequences of studied strains of Mycoplasma sp. 1220 shared 99.02-99.19 % nucleotide similarity with M. anatis strains but demonstrated ≤95.00-96.70 % nucleotide similarity to the 16S rRNA genes of other species of the genus Mycoplasma. Phylogenetic, average nucleotide and amino acid identity analyses revealed that the novel species was most closely related to Mycoplasma anatis. Based on the genetic data, we propose a novel species of the genus Mycoplasma, for which the name Mycoplasma anserisalpingitidis sp. nov. is proposed with the type strain 1220^T (=ATCC BAA-2147^T=NCTC 13513^T=DSM 23982^T). The G+C content is 26.70 mol%, genome size is 959110 bp.

Molecular cloning and functional analysis of TRAF6 from Yangzhou great white goose Anser anser

TNF receptor-associated factor 6 (TRAF6) is an adaptor protein and an E3 ubiquitin ligase mediating multiple cell signaling pathway activation in a context-dependent manner. TRAF6 plays critical roles in innate immune response and regulates function of antigen-presenting cells. Here, we cloned the goose TRAF6 (goTRAF6) gene from a healthy Yangzhou great white goose (Anser anser), which had a typical TRAF structure and shared a high-sequence identity with TRAF6 of other birds. Quantitative real-time PCR revealed that goTRAF6 mRNA was broadly expressed in all the studied tissues, with highest expression in the heart and pectoral muscle. Overexpression of goTRAF6 caused NF-κB activation in a dose-dependent manner and substantially upregulated IFN-β expression in HEK293T cells. Following Toll-like receptor (TLR) ligand stimulation of goose peripheral blood mononuclear cells, goTRAF6 and downstream inflammatory cytokine mRNA levels considerably up-regulated, especially at early stages. Salmonella Enteritidis challenge caused overexpression of goTRAF6 and cytokine mRNA in all the examined organs. These findings demonstrated that goTRAF6 played a substantial role in TLR-TRAF6 signaling cascade, and further contributed to the antibacterial-responses in host.