Rigidity of circulating lymphocytes is primarily conferred by vimentin intermediate filaments.
Lymphocytes need rigidity while in circulation, but must abruptly become deformable to undergo transmigration into tissue. Previously, the control of leukocyte deformability has been attributed to microfilaments or microtubules, but the present studies demonstrate the greater importance of vimentin intermediate filaments (IFs). In circulating T lymphocytes, IFs form a distinctive spherical cage that undergoes a rapid condensation into a juxtanuclear aggregate during chemokine-induced polarization. Measurements of the resistance of peripheral blood T lymphocytes to global deformation demonstrate that their rigidity is primarily dependent on intact vimentin filaments. Microtubules, in contrast, are not sufficient to maintain rigidity. Thus, vimentin IFs are a primary source of structural support in circulating human lymphocytes, and their regulated collapse is likely to be an essential element in chemokine-induced transendothelial migration.
Brown
M J
MJ
Experimental Immunology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Hallam
J A
JA
Colucci-Guyon
E
E
Shaw
S
S
D000818:Animals; D001775:Blood Circulation / Q000276:immunology* / Q000502:physiology*; D002462:Cell Membrane / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D002467:Cell Nucleus / Q000502:physiology; D016764:Cell Polarity / Q000502:physiology; D002469:Cell Separation; D048429:Cell Size / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D007382:Intermediate Filaments / Q000187:drug effects / Q000502:physiology*; D007399:Interphase / Q000502:physiology; D008387:Marine Toxins; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D010080:Oxazoles / Q000494:pharmacology; D013314:Stress, Mechanical; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D014746:Vimentin / Q000096:biosynthesis / Q000097:blood / Q000235:genetics / Q000502:physiology*
D008387:Marine Toxins; D010080:Oxazoles; D014746:Vimentin; C059041:calyculin A