Fig. 6.

Structure of GFP-MxA bodies in the cytoplasm of Huh7 cells by CLEM and an interpretative schematic. Panel A. Huh7 cells plated sparsely on a gridded coverslip 35 mm plate were transfected with the GFP-MxA expression vector and fixed with paraformaldehyde two days later. The cells were first imaged by fluorescence light microscopy, and location of GFP-positive cells identified. The cultures were processed further for thin-section EM focusing on the GFP-positive cells. Panel A illustrates thin-section EM of a GFP-positive cell showing MxA “bodies” (solid arrows) associated with intermediate filaments (dotted arrows, and “IF”) as well as swollen mitochondria (“M”). Additional experiments confirm that the MxA-bodies correspond to GFP fluorescence (data not shown). Inset show one such “MxA body” at higher magnification. Scale bar = 1 μm. Panel B. Interpretive schematic of MxA at the plasma membrane and in variably-sized clusters of individual MxA vesiculo-tubular elements some of which associated with and stretched out alongside cytoskeletal elements (intermediate filaments and/or microtubules). The mechanism for cross-talk between MxA structures and mitochondria (leading to swelling and reduced function) remains open to further exploration