HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Data Supplement Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Google Scholar Articles by Sanborn, K. B. Articles by Orange, J. S. PubMed PubMed Citation Articles by Sanborn, K. B. Articles by Orange, J. S.

Myosin IIA Associates with NK Cell Lytic Granules to Enable Their Interaction with F-Actin and Function at the Immunological Synapse¹

Keri B. Sanborn^*, Gregory D. Rak, Saumya Y. Maru, Korey Demers^¶, Analisa Difeo, John A. Martignetti, Michael R. Betts^¶, Rémi Favier^||, Pinaki P. Banerjee and Jordan S. Orange^2,*,,

^* Immunology Graduate Group, University of Pennsylvania School of Medicine, Philadelphia, PA 19104; Cell Biology and Physiology Graduate Program, University of Pennsylvania School of Medicine, Philadelphia, PA 19104; Joseph Stokes Jr. Research Institute of the Children’s Hospital of Philadelphia, Philadelphia, PA 19104; Department of Genetics and Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029; ^¶ Department of Microbiology, University of Pennsylvania, Philadelphia, PA 19104; and ^|| Assistance Publique-Hôpitaux de Paris, Centre de Référence des Pathologies Plaquettaires, Armand Trousseau Children’s Hospital, 75012; INSERM U790, Villejuif, France

NK cell cytotoxicity requires the formation of an actin-rich immunological synapse (IS) with a target cell and the polarization of perforin-containing lytic granules toward the IS. Following the polarization of lytic granules, they traverse through the actin-rich IS to join the NK cell membrane in order for directed secretion of their contents to occur. We examined the role of myosin IIA as a candidate for facilitating this prefinal step in lytic NK cell IS function. Lytic granules in and derived from a human NK cell line, or ex vivo human NK cells, were constitutively associated with myosin IIA. When isolated using density gradients, myosin IIA-associated NK cell lytic granules directly bound to F-actin and the interaction was sensitive to the presence of ATP under conditions of flow. In NK cells from patients with a truncation mutation in myosin IIA, NK cell cytotoxicity, lytic granule penetration into F-actin at the IS, and interaction of isolated granules with F-actin were all decreased. Similarly, inhibition of myosin function also diminished the penetration of lytic granules into F-actin at the IS, as well as the final approach of lytic granules to and their dynamics at the IS. Thus, NK cell lytic granule-associated myosin IIA enables their interaction with actin and final transit through the actin-rich IS to the synaptic membrane, and can be defective in the context of naturally occurring human myosin IIA mutation.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ This work was supported by National Institutes of Health Grant R01-AI067946 (to J.S.O.). K.B.S. was supported by National Institutes of Health Training Grant T32-GM07229.

² Address correspondence and reprint requests to Dr. Jordan S. Orange, Children’s Hospital of Philadelphia, Division of Immunology, Abramson Research Center 1014H, 3615 Civic Center Boulevard, Philadelphia, PA 19104. E-mail address: orange{at}mail.med.upenn.edu

³ Abbreviations used in this paper: IS, immunological synapse; eNK, ex vivo NK cell; TIRF, total internal reflection fluorescence; EM, electron microscopy; MTOC, microtubule organizing center.

⁴ The online version of this article contains supplementary material.