Additional file 13 of Lumpy skin disease virus suppresses the antiviral response of bovine peripheral blood mononuclear cells that support viral dissemination

Additional file 13. LSDV GFP viruses disseminated to permissive cells from infected PBMCs by direct contact. PBMCs (A) or primary fibroblasts (B) infected with LSDV-GFP strains were co-cultured with MDBK-Ruby cells constitutively expressing the red fluorescent protein mRuby3. Images were acquired at 4 dpi (A) or at the indicated times (B). White arrowheads depict infected fibroblasts (GFP-positive, Ruby negative), which disseminate at 2 dpi to MDBK-Ruby cells (white stars, double positive for GFP and Ruby). (C) To evaluate the contribution of indirect versus direct LSDV-GFP transmission from infected PBMCs, MDBK cells were either seeded into a transwell inset (0.4 µ membrane pore size) placed into a well containing infected PBMCs (C, left) or directly overlaid on the infected PBMCs (C, right). At 4 dpi, cells were fixed, counterstained with Hoechst (DNA stain) and imaged to reveal GFP-positive cells infected by LSDV-GFP. Scale bar 100 µm (A, B), 500 µm (C).