The specific ways in which T cells self-regulate their migratory behaviors during various physiological processes, including immune activation, interstitial migration or immune synapses, greatly depend on cell mechanical properties and the mechanical constraints of the extracellular environment. During aging, changes across immune T cells overall contribute to a decrease in immunological competence, a progression broadly referred to as immunosenescence. The aging-dependent decline of T-cell competence has been mostly studied in terms of differentiation, proliferation, receptor expression, genetic and epigenetic alterations or metabolism. Yet, the question of how Resumen v Abbreviations and notation vii Abbreviations and notation The following abbreviations are used in this thesis: AFM Atomic force microscopy A. nidulans Aspergillus nidulans AFs Actin filaments APCs Antigen-presenting cells AT Acoustic tweezers BCRs B-cell receptors CD11 Integrin alpha L CD18 Integrin beta chain-2 CD4 + T cell T lymphocyte that recognizes peptides on MHC class II molecules, also known as helper T cell CD62L -CD44 + Surface-protein phenotype expressed by mouse memory T lymphocytes CD62L + CD44 -Surface-protein phenotype expressed by mouse naive T lymphocytes CD8 + T cell T lymphocyte that recognizes peptides on MHC class I molecules, also known as cytotoxic T cell CMV Cytomegalovirus CTLs Cytotoxic T lymphocytes CV Coefficient of variation (i.e. mean/ standard deviation x 100 %)