Joanna Działo’s research while affiliated with University of Szczecin and other places

RHD virus (RHDV), which causes rabbit hemorrhagic disease, is the object of phylogenetic studies. The results of these studies provide valuable information on this pathogen. The purpose of present review is to summarize current knowledge about the phylogenetic position of this virus. The paper discusses the results of previous phylogenetic studies of RHDV, including factors affecting the shape of the phylogeny of this species and the diversity of RHDV strains in different parts of the world. It also presents the results of phylogenetic analysis of RHDV enriched with non-pathogenic and low pathogenic strains of rabbit lagoviruses, as well as phylogenetic analyses performed using modern Bayesian methods. The paper also highlights the unclear situation of Lagovirus taxonomy and shows selected data on the evolution of RHDV, gathered using phylogenetic methods. Finally, the possibility of using rabbit lagoviruses as a model for the study of the evolution of mammalian ssRNA(+) viruses has been shown.

The paper describes the assessment of B lymphocytes with CD19+ receptor, as well as T lymphocytes with receptor CD5+, and their subpopulations - T lymphocytes with CD4+, CD8+, CD25+ receptors, in rabbits infected with seven haemagglutinating strains of RHDV from various European countries. The aim of the study was to find out if the newly observed strains carry the same or similar immunological properties as the RHDV strains analysed previously. The study was performed on 70 mixed-breed rabbits divided into 7 groups of infected animals (consisting of 5 animals each), corresponding to the analyzed RHDV strains. For each of seven groups of infected animals a corresponding group of control animals was assigned (consisting of 5 animals each). The dynamics of the chosen lymphocytes and their subpopulations was assessed with the use of flow cytometry and monoclonal antibodies. The results of the study enable the authors to conclude that those 7 strains resemble Czech strains and may be qualified as strains with medium immunogenicity, forming one immunotype.

Cell death is one of the processes that are currently extensively studied. Beside the commonly used terminology regarding cell death, i.e. apoptosis, autophagy, necrosis, and cornification, in recent years there has been a growing number of additional definitions of this process, such as mitotic catastrophe, anoikis, entosis, paraptosis, pyroptosis, pyronecrosis, excitotoxicity, and Wallerian degeneration, which are described in 2009 by the Nomenclature Committee on Cell Death as atypical. The recent report of that Committee significantly alter the classification and nomenclature of the cell death processes, in which excitotoxicity and Wallerian degeneration have not been taken into account. Thus the present review describes excitotoxicity, and Wallerian degeneration, as two processes associated to cell death phenomena characteristic for nervous system. Excitotoxicity is a neuronal death caused by excessive, or prolonged activation of receptors for the excitatory amino acids. Depending on the intensity of the initiating stimulus, the excitotoxicity may overlap with other types of cell death such as apoptosis and necrosis. Wallerian degeneration is a process that results when a nerve fiber is cut or crushed, in which the part of the axon separated from the neuron's cell body degenerates distal to the injury. Wallerian degeneration is not a typical cell death mechanism, since neurons undergoing this process remain alive.

The pathogenicity of RHDV (rabbit haemorrhagic disease virus) is mainly associated with its affinity to blood vessels, with causing disseminated intravascular coagulations (DIC), and with the stimulation of the host immune system. Moreover, there are implications suggesting that apoptosis may be a pivotal process in understanding the basis of viral haemorrhagic disease in rabbits - a serious infectious disease causing mortality to wild and domestic rabbits. The aim of this study is to evaluate, by means of flow cytometry, the dynamics of apoptosis in peripheral blood granulocytes and lymphocytes in rabbits experimentally infected with seven different strains of RHDV and so-called antigenic variants of RHDV denominated as RHDVa, i.e.: Hungarian 24V/89, 1447V/96, 72V/2003; Austrian 01-04, 237/04, V-412 and French 05-01. The results showed that all of the RHDV and RHDVa strains cause an increase in the number of apoptotic cells throughout the infection, which might indicate the need for further analysis of the importance of this process.

The paper concerns the use of a novel, very effective diagnostic method, a real-time PCR for diagnosis of a viral agent causing viral haemorrhagic disease in rabbits - RHDV. Until now, the method was widely used for detecting many different viruses, both DNA, and RNA, but as far as RHDV is concerned, there are not many records of such use. This study aimed at the detection of 17 different strains from different European regions, differing in biological features and mortality. The study confirmed that real-time PCR is an applicable and effective method for diagnosis of RHDV, irrespective of the stains' features.

The paper describes non-specific immunity mediated by parameters of cell and humoral immunity in rabbits experimentally infected with seven haemagglutinating strains of the rabbit haemorrhagic disease (RHD) virus, including one which is an antigenic variant of RHDV, originating from various European countries and with a different isolation time. In addition to the studies performed earlier on different strains of RHDV, this paper also shows that the immunological differences between the strains may be the core of the existence of immunotypes among RHDV.

Neutrophils are one of the first cells of the immune system recruited to the site of infection, representing the host's most effective and numerous front-line defenders. Recently, a novel antimicrobial mechanism of neutrophils has been described: upon activation, they release DNA and a subset of their granule content, forming neutrophil extracellular traps (NETs). These extracellular, chromatin structures, which contain histones and neutrophil granule proteins, can trap and kill a broad spectrum of microbes, including Gram-positive and Gram-negative bacteria, fungi, protozoa and viruses. Some of the pathogens, which are trapped and exposed to high local concentrations of antimicrobial compounds, employ strategies against NET binding, including surface modification and/or degradation of NET by DNases. It has been suggested that NETs are formed during active cell death, recently named NETosis. New data indicate that this novel mechanism of cell death requires interaction between three processes--reactive oxygen species generation, histone citrullination and autophagy--and significantly differs from previously known types of cell death, including apoptosis and necrosis. Moreover, the release of nuclear chromatin was also described for other types of cells--mast cells and eosinophils. Mast cells, like neutrophils, under certain conditions release nuclear chromatin and may undergo a similar active cell death program, while eosinophils release only mitochondrial chromatin, and its release does not lead to the death of these cells.

Helminths are multicellular eukaryotic parasites infecting many mammals, including humans. The mammalian immune system is a highly evolved network of cells and molecules that protects macroorganisms from invading pathogens. Immune processes involved in helminth infections are poorly understood. This paper presents the current view on the immune response in helminth infections. We also present new data on this subject, especially the interaction of helminths with PRR receptors and the role of newly discovered immune cells, such as nuocytes, MMPtype2 cells, nTh2 cells, Ih2 cells the sources of interleukin 13, which play a very important role in helminth infections.

MALT is the system of pivotal meaning to mucosal structures of the organisms of mammals. These structures comprise a huge area and are constantly being exposed to antigens. Within MALT there are lymphoid tissues that protect different parts of the organism. One of the well-known elements of MALT is GALT tissue, which takes care of mucosal structures of the gastrointestinal tract. In the respiratory system (in continuous contact with antigens), there are two types of MALT tissue. One is NALT - it protects the upper part of respiratory tract, and the other one is BALT - it protects the lower parts, especially bronchus. Those structures constitute an important element of the immunity system against endless number of antigens, on the effect of which the organism is still exposed. This paper describes GALT, NALT and BALT as crucial factors of the proper functioning of the organism.