ABSTRACT
Induction of autophagy by ectromelia virus (ECTV) in primary cultures of bone marrow-derived macrophages (BMDMs) was investigated. The results showed that ECTV infection of BMDMs resulted in increased formation of autophagosomes, increased level of LC3-II protein present in aggregates and extensive cytoplasmic vacuolization. These data indicate an increased autophagic activity in BMDMs during ECTV infection.
Subject(s)
Autophagy , Ectromelia virus/physiology , Ectromelia, Infectious/physiopathology , Macrophages/cytology , Animals , Cell Line , Cells, Cultured , Ectromelia, Infectious/metabolism , Ectromelia, Infectious/virology , Macrophages/metabolism , Macrophages/virology , Mice , Mice, Inbred BALB C , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolismABSTRACT
Autophagy is a self-degradation process of cellular components. It plays both antiviral and pro-viral roles in the life cycle of different viruses and the pathogenesis of different viral diseases. In this study, we evaluated autophagy induction in splenocytes of ectromelia virus (ECTV)-resistant C57BL/6 and ECTV-susceptible BALB/c mice during infection with the Moscow strain of the ectromelia virus (ECTV-MOS). Autophagy was analyzed using the Western blot method by assessing type II microtubule-associated protein 1 (MAP1) light chain 3 (LC3) and Beclin 1 expression levels relative to beta-actin. Results indicated an increased ratio of LC3-II to beta-actin in splenocytes of C57BL/6 mice only at 7 day post infection (d.p.i.) compared to uninfected animals. LC3-II/beta-actin and Beclin 1/beta-actin ratios in splenocytes of BALB/c mice increased at 5 d.p.i. and remained high until day 14 and 7 p.i., respectively. We confirmed the formation of autophagosome structures in the spleen of BALB/c mice by transmission electron microscopy (TEM). Moreover, autophagy accompanied necrosis in the splenocytes of infected animals. Results suggest that ECTV-MOS induced autophagy, especially in the spleen of the susceptible mouse strain, may support viral replication and promote cell necrosis.
Subject(s)
Autophagy/physiology , Ectromelia virus , Ectromelia, Infectious/pathology , Spleen/cytology , Animals , Male , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Spleen/pathologySubject(s)
CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Ectromelia virus/pathogenicity , Ectromelia, Infectious/immunology , Flow Cytometry/methods , Interleukin-17/metabolism , Animals , Ectromelia virus/immunology , Ectromelia, Infectious/virology , Interleukin-17/genetics , Interleukin-17/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , T-LymphocytesABSTRACT
AIMS: The objective of this study was to access APC-effector cell cluster formation in genetically susceptible BALB/c (H-2(d) ) mice infected with highly virulent Moscow strain of ectromelia virus (ECTV-MOS) and estimate of lymphocyte activation based upon expression of CD62L and CD44 molecules. METHODS AND RESULTS: APC-effector cell clusters were obtained by enzymatic digestion from draining lymph nodes (DLNs) and spleens of BALB/c mice. We found that APCs infected with ECTV-MOS form unstable clusters with effector cells, and thus may diminish T-cell activation at the early stage of mousepox. Different types of effector cells including T-cell subsets (CD4(+) and CD8(+) ), B cells and polymorphonuclear cells colocalize within individual clusters. Increase in CD19(+) B cells within APC-effector cell clusters during severe clinical mousepox may reflect B-cell activation. CONCLUSIONS: Our studies indicated vigorous changes in APC-effector cell cluster formation in genetically susceptible BALB/c mice during mousepox (up to 2 weeks). ECTV-MOS can modulate APC interactions with effector cells and consequently may impair T-cell activation probably owing to unstable cluster formation and/or subsequent weak stimulation by infected APCs at the early stages of mousepox. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of APC-effector cell cluster formation in BALB/c mice during mousepox. It gives us a new light on the mutual cell-cell interactions and development of the immune response during ECTV-MOS infection.
Subject(s)
Antigen-Presenting Cells/immunology , Ectromelia virus/immunology , Ectromelia, Infectious/immunology , Lymphocytes/immunology , Animals , Antigen-Presenting Cells/cytology , B-Lymphocytes/immunology , B-Lymphocytes/pathology , Disease Models, Animal , Ectromelia, Infectious/pathology , Gene Expression Regulation/immunology , Hyaluronan Receptors/genetics , L-Selectin/genetics , Lymphocyte Activation/immunology , Lymphocytes/pathology , Male , Mice , Mice, Inbred BALB C , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/pathologyABSTRACT
We describe here a contribution of virus-induced actin tails and filopodia in transmission of Ectromelia virus (ECTV) infection in permissive cells detected by the immunofluorescence and confocal microscopy. Immunoblot analysis revealed profoundly decreased beta-actin levels during ECTV replicative cycle in the infected cells 24 hrs post infection (p.i.). These results provided a basis for the further analysis of ECTV motion in the infected cells as well as for impact of ECTV infection on the cytoskeletal proteins.
