Structural modifications of macrophages initiated by tick-borne encephalitis virus

Macrophages are cells of natural immunity and play a key role in pathogenesis of viral infections. Results of ultrastructural research on macrophages infected with tick-borne encephalitis virus (TBEV), an agent that causes dangerous infections affecting nervous system in human beings and belongs to the Flaviviridae family, were shown here. Using virology methods, it was ascertained that the TBEV is consumed by macrophages and multiplies in them. Ultrastructural research showed that the virus penetrates into the cytoplasm by means of local plasmalemma lysis and newly synthesized virus particles escape from the cell by the same path. At the same time, induration of the perinuclear space of cytoplasm was observed, where ribosomes, microfilaments, ribonucleoprotein threats, and virus-specific structures, namely, nucleocapsids, tube formations, and viroplasts, were found in large quantities. On the surface of viroplasts, newly synthesized virus particles were visualized. Thus, evidence was presented that microphages can play certain role in spreading of TBEV and are the target of the virus. Like active antigen-presenting cells, such macrophages can modulate the protective response of an organism and affect the pathogenesis of tick-borne encephalitis.