Mechanical Communication at the Immunological Synapse

Abstract

Summary T and B lymphocytes communicate by forming immunological synapses with antigen-presenting target cells. These highly dynamic contacts are characterized by continuous cytoskeletal remodeling events, which not only structure the interface but also exert a considerable amount of mechanical force. In recent years, it has become increasingly clear that synaptic forces influence information transfer both into and out of the lymphocyte. Here, we review our current understanding of synapse mechanics, focusing on its role as an avenue for intercellular communication.

Cytoskeletal control of B cell responses to antigens

“…Sensing of the mechanical stress in the synapse provides feedback for signalling and cytoskeletal rearrangements, and has also been implicated in antigen discrimination 132 .…”

On how the immune system preferentially interacts with antigen‐specific molecules bound to antigen over unbound molecules, with emphasis on B cell receptor signalling

“…The greater complexity of the latter situation is evident, given that antigen is presented by an antigen presenting cell, and so even “signal 1” for T cells involves cell/cell interactions. We have suggested above that TcR‐mediated signals cannot be mediated by allosteric mechanisms, contrary to suggestions in the literature . We intend to discuss elsewhere ideas on how the generation of signal 1 might be initiated by T cells.…”

“…Therefore, we conclude that allosteric mechanisms are not plausible. Such allosteric conformational changes have been invoked as a signalling mechanism for mIg and for TcRs . The references for BcR signalling are very old.…”

Shigellaimpairs human T lymphocyte responsiveness by hijacking actin cytoskeleton dynamics and T cell receptor vesicular trafficking

“…The experiments were performed under brightfield illumination with brief use of standard fluorescence illumination between acquisitions to monitor the number of bacteria in the analysed Jurkat cells. Micropipettes used to hold Jurkat cells were prepared as described previously by others (Basu & Huse, ; Guillou et al, ; Guillou, Dahl, J‐MG, et al, ; Sawicka et al, ). Microindenters were prepared from the bead micropipettes, as described previously (Guillou, Babataheri, et al, ).…”

“…Cells were put into a Petri dish (Fluorodish, WPI, Sarasota, FL, USA) in a 4-ml medium and placed on the stage of an inverted microscope (TE300, Nikon Instruments, Tokyo, Japan) equipped with a 100× oil immersion, 1.3 NA objective (Nikon Instruments) on an air suspension The experiments were performed under brightfield illumination with brief use of standard fluorescence illumination between acquisitions to monitor the number of bacteria in the analysed Jurkat cells. Micropipettes used to hold Jurkat cells were prepared as described previously by others (Basu & Huse, 2017;Guillou, Dahl, J-MG, et al, 2016;Sawicka et al, 2017). Microindenters were prepared from the bead micropipettes, as described previously (Guillou, Babataheri, et al, 2016).…”