Host HDL biogenesis machinery is recruited to the inclusion of Chlamydia trachomatis-infected cells and regulates chlamydial growth

Authors

  • John V. Cox,

    Corresponding author
    • Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
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  • Nirun Naher,

    1. Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
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  • Yasser M. Abdelrahman,

    1. Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
    2. Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
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  • Robert J. Belland

    1. Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, USA
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For correspondence. E-mail jcox@uthsc.edu; Tel. (+1) 901 448 7080; Fax (+1) 901 448 7360.

Summary

Chlamydia trachomatis is an obligate intracellular bacterial pathogen that is the most common cause of sexually transmitted bacterial infections and is the etiological agent of trachoma, the leading cause of preventable blindness. The organism infects epithelial cells of the genital tract and eyelid resulting in a damaging inflammatory response. Chlamydia trachomatis grows within a vacuole termed the inclusion, and its growth depends on numerous host factors, including lipids. Although a variety of mechanisms are involved in the acquisition of host cell cholesterol and glycosphingolipids by C. trachomatis, none of the previously documented pathways for lipid acquisition are absolutely required for growth. Here we demonstrate that multiple components of the host high-density lipoprotein (HDL) biogenesis machinery including the lipid effluxers, ABCA1 and CLA 1, and their extracellular lipid acceptor, apoA-1, are recruited to the inclusion of C. trachomatis-infected cells. Furthermore, the apoA-1 that accumulates within the inclusion colocalizes with pools of phosphatidylcholine. Knockdown of ABCA1, which mediates the cellular efflux of cholesterol and phospholipids to initiate the formation of HDL in the serum, prevents the growth of C. trachomatis in infected HeLa cells. In addition, drugs that inhibit the lipid transport activities of ABCA1 and CLA 1 also inhibit the recruitment of phospholipids to the inclusion and prevent chlamydial growth.These results strongly suggest that C. trachomatis co-opts the host cell lipid transport system involved in the formation of HDL to acquire lipids, such as phosphatidylcholine, that are necessary for growth.

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