TY - JOUR AU - V. Evert PY - 1970/01/01 Y2 - 2024/03/28 TI - General aspects of pathogenesis and mechanisms of development of immunopathological changes at circovirus infection of pigs JF - Theoretical and Applied Veterinary Medicine JA - TAVM VL - 5 IS - 3 SE - Articles DO - UR - https://bulletin-biosafety.com/index.php/journal/article/view/155 AB - To date, there has been a clear idea of the circovirus infection of pigs as a multi-symptomatic disease, which is based on complex processes of immunosuppression. Most known circoviruses cause severe illness in young of susceptible animals, and in adults the infection has a latent course. PCV-2 causes a different degree of depletion of lymphoid cells and changes the immunological status of animals. PCV-2 is also associated with a number of pathological conditions of pigs: syndrome after weaning multisystem exhaustion, dermatitis-nephropathy syndrome, proliferative-necrotizing pneumonia, congenital tremor and perinatal myocarditis with reproductive impairment. More often, circovirus infection is aggravated by concomitant infections, which causes a more severe course of the disease. In addition, the involvement of PCV-2 in the infectious process can change the clinical picture of the disease, which leads to difficulties at diagnosing. The purpose of the work is to elucidate the general aspects of pathogenesis and mechanisms of development of immunopathological changes at the circovirus infection of pigs. The pathogenesis of circovirus infection of pigs is a multifactorial and dynamic process, the defining aspect of which is the slow rate of the disease, due to the specific biological and pathogenic properties of the pathogen that determine the features of its penetration into target cells and subsequent reproduction. To date there is no exhaustive theory that explains and takes into account all aspects of pathogenesis. In infected animals, the virus is found in cells of the lymphoid system (macrophages, dendritic cells, T lymphocytes and B lymphocytes), which are considered target cells for PCV-2. The virus is mainly targeted at cardiomyocytes, hepatocytes and macrophages of fetus, and monocytes in the early postpartum period, which eventually leads to depletion of lymphoid cells and immunosuppression. The disease is complicated by immunostimulation or joint infection with other pathogens. PCV-2 is able to be in macrophages and dendritic cells, modulating their functions. In infected PCV-2 pigs, the regulation of IL 10 and inflammatory cytokines, which contributes to the development of infection, is intensified. The development of immunopathological changes at circovirus infection covers all major structures and links of the hematopoiesis and immune defense system. The dynamics of the development of pathological processes in the organs of the immune system at pigs with circovirus infection depends on the stage of the infectious process and the hierarchical position of the organs in the system of hematopoiesis and immune defense. Features of immunopathological changes are determined by a combination of specific properties of the pathogen (moderate virulence, tropism to immune system cells, ability to persistent persistence in the antigen-presenting cells) with the development of a complex of immunopathological reactions. ER -