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Chapter 50 : Loss of a Patatin-Like Phospholipase A Causes Reduced Infectivity of Legionella Pneumophila in Amoeba and Machrophage Infection Models
Loss of a Patatin-Like Phospholipase A Causes Reduced Infectivity of Legionella Pneumophila in Amoeba and Machrophage Infection Models, Page 1 of 2< Previous page Next page > /docserver/preview/fulltext/10.1128/9781555815660/9781555813901_Chap50-1.gif /docserver/preview/fulltext/10.1128/9781555815660/9781555813901_Chap50-2.gif
Legionella pneumophila possesses a large variety of lipolytic enzyme activities that affect phospholipids. In addition to the phospholipid-degrading phospholipase A (PLA) and lysophospholipase A (LPLA) activities, glycerophospholipid:cholesterol acyltransferase (GCAT) activity has been described in this chapter. First, the authors were interested in whether all of the 11 PLP genes are expressed in L. pneumophila Philadelphia-1 during growth in laboratory media. In order to assess expression of the PLP genes, mRNA was isolated at four growth phases (early logarithmic, mid-logarithmic, late logarithmic, and early stationary) in standard laboratory media and subsequently used for reverse transcriptase PCR with L. pneumophila Philadelphia-1 PLP gene-specific primers. L. pneumophila wild type and the patA/vipD mutants were grown to late exponential phase, and cell lysates and culture supernatants of the bacteria were tested for PLA, LPLA, and lipase activities. Importantly, in coinfection assays with amoebae and macrophages, the L. pneumophila patA/vipD mutant strains were severely impaired for intracellular replication. Thus, PatA/VipD is a new type IVB secreted phospholipase of L. pneumophila with essential importance during host cell infection.
Key Concept Ranking
- Type IVB Secretion System