Modified live vaccine strains of porcine reproductive and respiratory syndrome virus cause immune system dysregulation similar to wild strains.

Introduction: Porcine reproductive and respiratory syndrome virus (PRRSV) emerged about 30 years ago and continues to cause major economic losses in the pork industry. The lack of effective modified live vaccines (MLV) allows the pandemic to continue.

Background And Objective: We have previously shown that wild strains of PRRSV affect the nascent T cell repertoire in the thymus, deplete T cell clones recognizing viral epitopes essential for neutralization, while triggering a chronic, robust, but ineffective antibody response.

The mechanism of immune dysregulation caused by porcine reproductive and respiratory syndrome virus (PRRSV).

PRRSV is capable of evading the effective immune response, thus persisting in piglets and throughout the swine herd. We show here that PRRSV invades the thymus and causes depletion of T-cell precursors and alteration of the TCR repertoire. Developing thymocytes are affected during negative selection when they transit from the triple-negative to triple-positive stages at the corticomedullary junction just before entering the medulla.

The immune system of the ferret () - A review.

The basic information dealing with the anatomy of the ferret's immune system, cross-reactivity of the ferret leukocytes with polyclonal and monoclonal antibodies   and immune response to the mitogens and various infections are presented. The leukocyte numbers in the peripheral blood in the ferrets are lower compared to other species and only one subclass of IgG has been identified in ferrets so far. Lymphocytes make up 12-67% of all the leukocytes in the peripheral blood of the healthy adult ferrets.

A ferret model of immunosuppression induced with dexamethasone.

Ferrets are nowadays frequently used as animal models for biomedical purposes; in many cases, immunosuppression of experimental animals is necessary. The aim of this study was to evaluate the effect of intramuscular dexamethasone administration (2 mg/kg as the initiation dose continued with 1 mg/kg q 12 h applied 5 times) on ferret's immune system. In comparison with ferrets which received the saline (n = 5), significantly lower total counts of leukocytes (P < 0.

Dynamics and Differences in Systemic and Local Immune Responses After Vaccination With Inactivated and Live Commercial Vaccines and Subsequent Subclinical Infection With PRRS Virus.

The goals of our study were to compare the immune response to different killed and modified live vaccines against PRRS virus and to monitor the antibody production and the cell mediated immunity both at the systemic and local level. In the experiment, we immunized four groups of piglets with two commercial inactivated (A1-Progressis, A2-Suivac) and two modified live vaccines (B3-Amervac, B4-Porcilis). Twenty-one days after the final vaccination, all piglets, including the control non-immunized group (C5), were i.

Monocyte derived macrophages as an appropriate model for porcine cytomegalovirus immunobiology studies.

Porcine cytomegalovirus (PCMV) causes lifelong latent infections in swine. The pathogen is occasionally associated with inclusion body rhinitis and pneumonia in piglets, reproductive disorders in pregnant sows and respiratory disease complex in older pigs. Immunosuppressive potential of PCMV infection is discussed.

Effects of adjuvants on the immune response of pigs after intradermal administration of antigen.

The ability of different adjuvants to enhance immune responses to intradermal (ID) immunisation with a model antigen was studied in pigs. Immune responses were evaluated with respect to the intensity of systemic and mucosal antibody formation, their isotype characterisation and rate of cell-mediated immunity. These findings were compared with the intensity of adverse local reactions.

Changes in lymphocyte function and subsets in dogs with naturally occurring chronic renal failure.

Chronic renal failure (CRF) causes immunosuppresion in humans and is thought to be one of the causes of noninfectious secondary immunosuppression in dogs. Hematological, biochemical, and immunological examinations were performed on blood samples obtained from dogs in various stages of CRF. The number of dogs with lymphopenia increased with the progression of clinical signs.

The structure and functional analysis of canine T-cell receptor beta region.

VDJ recombination is a key process in T-cell receptor (TCR) and immunoglobulin (Ig) molecules development. Comparison of ENSEMBL and GenBank database information revealed major differences in dog T-cell receptor beta (TRB) region annotations. ENSEMBL based genomic alignment of dog TRB sequence with human sequence and annotation showed a very similar structure of TRB.

Selected markers of cardiovascular disease in a population exposed to arsenic from drinking water.

This study examined prevalence and serum levels of selected markers of cardiovascular disease in 34 subjects from a Croatian rural population exposed to high levels of arsenic (As) from drinking water (611.89±10.06μg/l).

Flow cytometric analysis of bone marrow leukocytes in neonatal dogs.

Dogs represent both an important veterinary species and a convenient model for allogeneic hematopoietic stem cell transplantation. Even though anti-canine CD34 antibodies have recently become available, little is known about hematopoietic lineages in dogs, partially because CD34- cells have been ignored in all analyses performed so far. In this study, we have focused on the bone marrow mononuclear compartment to provide an additional piece of information on the phenotype of CD34+ progenitors and to identify the dominant CD34- population.