Cell/cell interactions are a paradigm in cell biology since they establish, through biochemical and mechanical contacts, the structures of the living matter, allowing the cells core functions to take place, with broad impacts in tissue structure and function. While the biochemical aspects of these interactions have been intensively studied for decades, the mechanical aspects, known as mechano-transduction, have only more recently attracted the interest of biologists. Its importance is increasingly recognized as being instrumental to finely regulate cellular functions. Lymphocytes, either T or B, live and function as single cells, and do not assemble in a continuous tissue, while they need to transiently contact each other in a one-to-one manner to allow their efficient activation and subsequent action. These contacts are at the origin of some of the forces, and forces can strongly affect, and even potentiate, the effector functions of immune cells. In the present review, we will present the actors and scales, and discuss the modes of operations of this mechanobiology in the particular frame of immunological cells.