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

J. Biol. Chem., Vol. 280, Issue 1, 9-17, January 7, 2005

This Article Full Text Full Text (PDF) All Versions of this Article: 280/1/9    most recent M411570200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Piboonpocanun, S. Articles by Voelker, D. R. Search for Related Content PubMed PubMed Citation Articles by Piboonpocanun, S. Articles by Voelker, D. R. Social Bookmarking                      What's this?

Surfactant Protein A Binds Mycoplasma pneumoniae with High Affinity and Attenuates Its Growth by Recognition of Disaturated Phosphatidylglycerols^*

Surapon Piboonpocanun, Hirofumi Chiba, Hiroaki Mitsuzawa, Wesley Martin, Robert C. Murphy, Ronald J. Harbeck, and Dennis R. Voelker¶

From the Program in Cell Biology, Department of Medicine and Department of Pediatrics, National Jewish Medical and Research Center, Denver, Colorado 80206 and the Department of Pharmacology, University of Colorado School of Medicine, Denver, Colorado 80262

Surfactant Protein A (SP-A) is an abundant, multifunctional lectin that resides within the bronchoalveolar compartment of the lung and plays an important role in the innate immunity of the organ. Mycoplasma pneumoniae is a human pathogen that resides in the same compartment as SP-A, and we examined the interaction between the two. Preparations of human and rat SP-A recognized the mycoplasma with high affinity in the presence of Ca²⁺, exhibiting apparent K^'_d values in the nanomolar range. Membranes prepared from the microbe also bound human and rat SP-A with similar characteristics and affinity to the intact cells. The ligand for SP-A was insensitive to proteolysis. Lipid extracts prepared from the mycoplasma, bound SP-A with high affinity when examined by ligand blot analysis. These lipid extracts were also potent competitive inhibitors (IC₅₀ = 0.2 nM) of human SP-A binding to mycoplasma membranes. The major lipid ligands for the protein identified by mass spectrometry are a group of disaturated phosphatidylglycerols. The addition of SP-A to cultures of M. pneumoniae markedly attenuated the growth of the organism assessed by colony formation, metabolic activity, and DNA replication. The bacteriostatic effects of SP-A were reversed by dipalmitoylphosphatidylglycerol. These findings demonstrate that human SP-A can play a direct role in antibody-independent immunity to M. pneumoniae by interacting with lipid ligands expressed on the surface of the organism and implicate SP-A in the immediate host response to the bacteria.

Received for publication, October 12, 2004

^* This work was supported by National Institutes of Health Grants HL45286, PO1-HL073907, and ALA-ARC 95. 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.

^¶ To whom correspondence should be addressed: Dept. of Medicine, National Jewish Medical and Research Center, 1400 Jackson St., Denver, CO 80206. Tel.: 303-398-1300; Fax: 303-398-1806; E-mail: voelkerd{at}njc.org.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				Y.-Z. Wu, Y. Manevich, J. L. Baldwin, C. Dodia, K. Yu, S. I. Feinstein, and A. B. Fisher Interaction of Surfactant Protein A with Peroxiredoxin 6 Regulates Phospholipase A2 Activity J. Biol. Chem., March 17, 2006; 281(11): 7515 - 7525. [Abstract] [Full Text] [PDF]

				X. Xu, D. Zhang, N. Lyubynska, P. J. Wolters, N. P. Killeen, P. Baluk, D. M. McDonald, S. Hawgood, and G. H. Caughey Mast Cells Protect Mice from Mycoplasma Pneumonia Am. J. Respir. Crit. Care Med., January 15, 2006; 173(2): 219 - 225. [Abstract] [Full Text] [PDF]