Fig. 5.

Role of α-tubulin in leukocyte uptake. α-Tubulin is stained using a specific primary antibody and Alexa Fluor 488 secondary antibody. CyTRAK orange is the live dye used to stain peripheral blood mononuclear cells before co-incubation with BEAS-2B as host cells. The nuclei are stained with DAPI. The figure displays several stages of engulfment of leukocytes by BEAS-2B, as a representative sample of > 150 CIC structures analysed: A α-tubulin cytoskeleton of a BEAS-2B host cell and a leukocyte before internalisation. B Establishment of a link between target and host cell; arrow marks ring-like condensation around leukocyte. C Host cell nucleus deformation; arrow demonstrates connection between α-tubulin ring and cytoskeleton of recipient cell. D Complete engulfment of the leukocyte by a BEAS-2B cell; arrow indicates ring-like structure still present around engulfed leukocyte. E Merged X-Y-Z scan of a representative cell-in-cell structure shows complete engulfment of leukocyte. Scale bars indicate 10 μm