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) 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 Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Carey, B. Articles by Trapnell, B. C. Search for Related Content PubMed PubMed Citation Articles by Carey, B. Articles by Trapnell, B. C.

PU.1 Redirects Adenovirus to Lysosomes in Alveolar Macrophages, Uncoupling Internalization from Infection¹

Brenna Carey^*, Margaret K. Staudt^2,*, Dana Bonaminio^*, Johannes C. M. van der Loo and Bruce C. Trapnell^3,*,,

Divisions of ^* Pulmonary Biology, Pulmonary Medicine, and Experimental Hematology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229; and Division of Pulmonary, Critical Care and Sleep Medicine, University of Cincinnati College of Medicine, Cincinnati, OH 45267

Adenovirus is endocytosed and efficiently destroyed by human and murine alveolar macrophages (AMs) and rapidly cleared from the lungs of wild-type but not GM-CSF^–/– mice. We hypothesized that GM-CSF may regulate adenovirus clearance in AMs via the transcription factor PU.1 by redirecting virion trafficking from the nucleus to lysosomes. This hypothesis was tested in murine AM cell lines with altered GM-CSF and/or PU.1 expression including MH-S (GM-CSF^+/+PU.1^Pos), mAM (GM-CSF^–/–/PU.1^Neg), and mAM_PU.1+ (GM-CSF^–/–/PU.1^Pos; PU.1-transduced mAM cells) and A549 (an epithelial-like cell line) using a human adenovirus expressing a -galactosidase reporter. In PU.1^Neg mAM and A549 cells, adenovirus efficiently escaped from endosomes, translocated to the nucleus, and expressed the viral reporter in most cells. In marked contrast, in PU.1^Pos mAM_PU.1+ and MH-S cells, adenovirus failed to escape from endosomes, colocalized exclusively with endosome/lysosome markers (Rab5, Rab7, and Lamp1), and rarely expressed the reporter. Retroviral expression of PU.1 in A549 cells blocked endosomal escape, nuclear translocation and reporter expression. Inhibition of endosome acidification also blocked escape, nuclear translocation, and reporter expression in PU.1^Neg cells. The effect of PU.1 on viral trafficking and transduction could not be explained by an effect on endosome acidification or on differences in viral load. PU.1 reduced expression of integrin ₅, a host factor important for endosomal escape of adenovirus, suggesting that PU.1 redirects adenoviral trafficking by modulating integrin signaling. These results demonstrate that PU.1 uncouples infection from internalization in AMs, providing a mechanism for AMs to avoid infection by adenovirus during clearance.

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 Grants HL69549 and HL071823 (to B.C.T.).

² Current address: Laboratory of Neuro-Oncology, Rockefeller University, 1230 York Avenue, New York, NY 10021.

³ Address correspondence and reprint requests to Dr. Bruce Trapnell, Cincinnati Children’s Hospital Medical Center, Division of Pulmonary Biology, 3333 Burnet Avenue, Cincinnati, OH 45229. E-mail address: Bruce.Trapnell{at}cchmc.org

⁴ Abbreviations used in this paper: AM, alveolar macrophage; Lamp1, lysosome-associated membrane protein-1; -gal, -galactosidase; BAF, bafilomycin A₁.

This article has been cited by other articles:

				J. G. Smith, A. Cassany, L. Gerace, R. Ralston, and G. R. Nemerow Neutralizing Antibody Blocks Adenovirus Infection by Arresting Microtubule-Dependent Cytoplasmic Transport J. Virol., July 1, 2008; 82(13): 6492 - 6500. [Abstract] [Full Text] [PDF]