Dynamic polarization of the microtubule cytoskeleton during CTL-mediated killing.
Efficient unidirectional killing by cytotoxic T lymphocytes (CTL) requires translocation of the microtubule organizing center (MTOC) to the target cell contact site. Here we utilize modulated polarization microscopy and computerized 3D reconstruction of tubulin and LFA-1 immunofluorescence images to investigate how this is accomplished. The results show that the MTOC is drawn vectorially to the contact site by a microtubule sliding mechanism. Once the MTOC arrives at the contact site, it oscillates laterally. Microtubules loop through and anchor to a ring-shaped zone (pSMAC) defined by the dense clustering of LFA-1 at the target contact site. Microtubules that run straight between the MTOC and pSMAC and then turn sharply may indicate the action of a microtubule motor such as dynein.
Kuhn
Jeffrey R
JR
Division of Molecular Cell and Developmental Biology, 141 Patterson Labs, University of Texas at Austin, Austin, TX 78712, USA.
Poenie
Martin
M
D000818:Animals; D003599:Cytoskeleton / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D051379:Mice; D008808:Mice, Inbred CBA; D008859:Microscopy, Polarization; D008870:Microtubules / Q000737:chemistry / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D016169:Lymphocyte Function-Associated Antigen-1