Abstract
Previous studies have shown that L. pneumophila multiplies intracellularly in human monocytes and alveolar macrophages within a membrane-bound cytoplasmic vacuole studded with ribosomes. In this paper, the formation of this novel vacuole is examined. After entry into monocytes, L. pneumophila resides in a membrane-bound vacuole. During the first hour after entry, vacuoles containing L. pneumophila are found surrounded by smooth vesicles fusing with or budding off from the vacuolar membrane and by mitochondria closely apposed to the vacuolar membrane. By 4 h, vacuoles are found less frequently surrounded by these cytoplasmic organelles, but now ribosomes and rough vesicles are found gathered about the vacuole. By 8 h, the ribosome- lined vacuole has formed. Erythromycin, at concentrations that completely inhibit the intracellular multiplication of L. pneumophila, has no effect on vacuole formation. Formalin-killed L. pneumophila also reside in a membrane-bound vacuole after entry into monocytes. In contrast to the situation with live L. pneumophila, cytoplasmic organelles are not found surrounding vacuoles containing formalin- killed L. pneumophila at any time after entry. Formalin-killed bacteria are rapidly digested, and by 4 h, few remain intact. The L. pneumophila- containing vacuole has certain features in common with other intracellular organisms that inhibit phagosome-lysosome fusion; these organisms may share a common mechanism for vacuole formation and inhibition of phagosome-lysosome fusion.
Full Text
The Full Text of this article is available as a PDF (1.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Friis R. R. Interaction of L cells and Chlamydia psittaci: entry of the parasite and host responses to its development. J Bacteriol. 1972 May;110(2):706–721. doi: 10.1128/jb.110.2.706-721.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Glavin F. L., Winn W. C., Jr, Craighead J. E. Ultrastructure of lung in Legionnaires' disease. Observations of three biopsies done during the Vermont epidemic. Ann Intern Med. 1979 Apr;90(4):555–559. doi: 10.7326/0003-4819-90-4-555. [DOI] [PubMed] [Google Scholar]
- Hirsch J. G., Fedorko M. E. Ultrastructure of human leukocytes after simultaneous fixation with glutaraldehyde and osmium tetroxide and "postfixation" in uranyl acetate. J Cell Biol. 1968 Sep;38(3):615–627. doi: 10.1083/jcb.38.3.615. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Horwitz M. A., Silverstein S. C. Influence of the Escherichia coli capsule on complement fixation and on phagocytosis and killing by human phagocytes. J Clin Invest. 1980 Jan;65(1):82–94. doi: 10.1172/JCI109663. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Horwitz M. A., Silverstein S. C. Intracellular multiplication of Legionnaires' disease bacteria (Legionella pneumophila) in human monocytes is reversibly inhibited by erythromycin and rifampin. J Clin Invest. 1983 Jan;71(1):15–26. doi: 10.1172/JCI110744. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Horwitz M. A., Silverstein S. C. Legionnaires' disease bacterium (Legionella pneumophila) multiples intracellularly in human monocytes. J Clin Invest. 1980 Sep;66(3):441–450. doi: 10.1172/JCI109874. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones T. C., Hirsch J. G. The interaction between Toxoplasma gondii and mammalian cells. II. The absence of lysosomal fusion with phagocytic vacuoles containing living parasites. J Exp Med. 1972 Nov 1;136(5):1173–1194. doi: 10.1084/jem.136.5.1173. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lawn A. M., Blyth W. A., Taverne J. Interactions of TRIC agents with macrophages and BHK-21 cells observed by electron microscopy. J Hyg (Lond) 1973 Sep;71(3):515–528. doi: 10.1017/s0022172400046507. [DOI] [PMC free article] [PubMed] [Google Scholar]
- REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]