Paulina Niedźwiedzka-Rystwej

Non-specific immunity in rabbits infected with 10 strains of the rabbit haemorrhagic disease virus with different biological properties

To determine the parameters of non-specific immunity in rabbits infected with 10 biologically different strains of the rabbit haemorrhagic disease (RHD) virus (BS89, Hagenow, Rainham, Frankfurt, Asturias, Vt97, Triptis, Hartmannsdorf, Pv97, 9905 RHDVa) the following indices were assessed: polimorphonuclear cell (PMN) adherence capacity, absorption index, percentage of absorbing cells, spontaneous, stimulated as well as spectrophotometric test for reduction of the nitroblue tetrazolium (NBT), metabolic activity coefficient of neutrophilic granulocytes, stimulation index, myeloperoxidase activity, lysozyme concentration and activity index. The symptoms and the percentage of mortality in animals infected were recorded. On the basis of the estimated parameters, the present study confirmed the existence of immunotypes among the strains of the RHD virus. However, the results did not indicate a connection between biological property of the RHD virus (haemagglutination capacity and generation of antigenic variants) and the immunological profile of the strains.

Apoptosis of peripheral blood leukocytes from rabbits infected with non-haemagglutinating strains of rabbit haemorrhagic disease virus (RHDV).

The report demonstrates that the induction of apoptosis in peripheral blood granulocytes and lymphocytes of rabbits infected with three non-haemagglutinating RHDV strains (English Rainham, German Frankfurt, and Spanish Asturias) is a crucial determinant of the pathogenesis of rabbit haemorrhagic disease. Apoptosis was measured by flow cytometric detection of caspase activity. These studies demonstrated that the investigated RHDV (rabbit haemorrhagic disease virus) viral strains affected leukocyte apoptosis to varying degrees. Enhanced leukocyte apoptosis was detected between 4 and 36 h after infection and was more pronounced in lymphocytes than in granulocytes. The data presented here thus provide a preliminary understanding of the kinetics of apoptosis in leukocytes of rabbits infected with RHDV.

Mechanisms of type I interferon action and its role in infections and diseases transmission in mammals

Interferons (IFNs) are pivotal regulators of immunological processes. This paper describes mainly type I interferons -α and -β and their recently recounted signaling pathways, especially connected with ISGs - interferon stimulated genes, having a crucial role in regulating IFN recruitment. Moreover, the paper shows the data on the role of interferons -α and -β in infections - not only commonly known viral infections, but also bacterial, fungal and parasitic.

Stress granules (SG) and processing bodies (PB) in viral infections.

During reaction to stress caused by viral infection, RNA granules are formed in order to protect mRNA. Stress granules (SG) and processing bodies (PB) provide cell homeostasis and mRNA stability. They are formed, for example, during polio virus and MRV (mammalian orthoreovirus) infections. Some viruses, such as influenza virus and HTLV-1 (Human T-lymphotropic virus 1), block the formation of granules. In addition, there are viruses like West Nile Virus, Hepatitis C Virus (HCV) or human Herpes viruses, which influence the functioning of the granules.

Immunological memory cells

This article reviews immunological memory cells, currently represented by T and B lymphocytes and natural killer (NK) cells, which determine a rapid and effective response against a second encounter with the same antigen. Among T lymphocytes, functions of memory cells are provided by their subsets: central memory, effector memory, tissue-resident memory, regulatory memory and stem memory T cells. Memory T and B lymphocytes have an essential role in the immunity against microbial pathogens but are also involved in autoimmunity and maternal-fetal tolerance. Furthermore, the evidence of immunological memory has been established for NK cells. NK cells can respond to haptens or viruses, which results in generation of antigen-specific memory cells. T, B and NK cells, which have a role in immunological memory, have been characterized phenotypically and functionally. During the secondary immune response, these cells are involved in the reaction against foreign antigens, including pathogens, and take part in autoimmune diseases, but also are crucial to immunological tolerance and vaccine therapy.

White and red blood cell picture in rabbits experimentally infected with strains of the rabbit haemorrhagic disease (RHD) virus without or with variable haemagglutination capacity.

The aim of the study was to establish if haemagglutination of rabbit haemorrhagic disease virus (RHDV) affects haematological picture of peripheral blood in rabbits and the pathogenicity of the virus. The study analyzed white and red blood cell picture in rabbits experimentally infected with two non-haemagglutinating (HA-) RHDV strains (Frankfurt and Asturias) and one strain with variable haemagglutination capacity (HA+/-) (Hagenow). Studies with HA- and HA +/- are rare and relate only to 4 HA- strains (2 RHDV: BLA and Rainham; 2 RHDVa: Pv97 and 9905) and 1 HA+/- RHDV strain: ŻD, where less changes in haematological indices and less pathogenicity were observed. We found that changes caused by HA- Frankfurt strain were related to the number of neutrophils and thrombocytes, while in HA- strain Asturias, in thrombocytes and leukocytes. Changes evoked by HA+/- Hagenow strain pertained to the number of eosinophils, thrombocytes, leukocytes, monocytes, and concentration of hemoglobin. Mortality caused by the Frankfurt strain was 100% between 36 and 48 h post infection (p.i.), while that caused by Asturias strain was 100% between 24 and 36 h p.i., and that observed in case of Hagenow strain was 90% between 36 and 48 h p.i. The changes in haematological picture caused by the HA- and HA+/- RHDV strains were less intensive than those found in case of the HA+ RHDV strains, which cannot be confirmed for pathogenicity, and is not in line with the existing hypothesis suggesting higher pathogenicity in HA+ viruses.

Values of B and T cells and their subpopulations in peripheral blood of rabbits

1 Department of Immunology, Faculty of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland, e-mail: kuki001@interia.pl 2 Domestic Animal Clinic, Łubinowa 17, Szczecin, Poland 3 Department of Microbiology, Faculty of Biology, University of Szczecin, Felczaka 3c, 71-412 Szczecin, Poland. 4 Center of Molecular Biology and Biotechnology, Faculty of Biology, University of Szczecin, Szczecin, Poland

Hematological parameters in Polish mixed breed rabbits with addition of meat breed blood in the annual cycle.

In the paper we studied haematologic values, such as haemoglobin concentration, haematocrit value, thrombocytes, leucocytes: lymphocytes, neutrophils, basophils, eosinophils and monocytes in the pheral blood in Polish mixed-breeds with addition of meat breed blood in order to obtain the reference values which are until now not available for this animals. In studying this indices we took into consideration the impact of the season (spring, summer, autumn, winter), and sex of the animals. The studies have shown a high impact of the season of the year on those rabbits, but only in spring and summer. Moreover we observed that the sex has mean impact on the studied values of haematological parameters in those rabbits. According to our knowledge, this is the first paper on haematologic values in this widely used group of rabbits, so they may serve as reference values.

B and T cell values in peripheral blood in Polish mixed breed rabbits.

Due to the lack of reference values for immunological parameters in Polish mixed breed rabbits, the study was aimed at developing standards for B-cells with CD19+ receptor, and T-cells with CD5+ receptor, and their subpopulations, namely T-cells with receptors CD4+, CD8+ and CD25+ in peripheral blood of Polish mixed breed rabbits, as well as at assessing the impact of four seasons and sex of the animals on such values. The results of the study not only are the source of reference values, but also revealed that the season of the year and sex of the rabbits affect the percentage of B- and T-cells and their subpopulations in peripheral blood.

Characteristics of T lymphocyte subpopulations

The paper describes the characteristics, receptor profile and functions of T lymphocyte subpopulations (helper, cytotoxic, regulatory, memory and others). Among T helper cells one can enumerate Th0, Th1, Th2, Th9, Th17, Th22, T(FH) and nTh2, while T cytotoxic cells include Tc, NKT, Tγδ, and T CD8αα (IEL). Among regulatory cells there are nTreg, iTreg, T(R)1, and iT(R)35, as well as T lymphocytes with CD8, such as CD8+CD122+, CD8+CD28-, and CD11c+CD8+. And among memory T cells there are Tcm and Tem. Moreover, there are some so-called other T cells, such as Tn (T αβ CD4+ and T αβ CD8+), T exhausted and T anergic.