Non-chemotactic influence of CXCL7 on human phagocytes. Modulation of antimicrobial activity against L. pneumophila.

Authors: González-Cortés C, Diez-Tascón C, Guerra-Laso JM, González-Cocaño MC, Rivero-Lezcano OM Abstract We have investigated the role of CXCL7 in the immune response of human phagocytes against the intracellular bacteria Mycobacterium tuberculosis and Legionella pneumophila. We have observed that polymorphonuclear neutrophil (PMN) chemotaxis induced by the supernatants of infected monocyte derived macrophages (MDM) may be attributed to CXCL8 rather than CXCL7, although both chemokines are present in large quantities. We have also found that CXCL7 is present not only in the supernatants of MDM, but also in the supernatants of PMN of some, but not all, individuals. Western blot analysis revealed that, in both MDM and PMN supernatants appeared two bands with molecular weights c...

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Modulation of Rab GTPase function by a protein phosphocholine transferase

Authors: Shaeri Mukherjee, Xiaoyun Liu, Kohei Arasaki, Justin McDonough, Jorge E. Galán & Craig R. RoyThe intracellular pathogen Legionella pneumophila modulates the activity of host GTPases to direct the transport and assembly of the membrane-bound compartment in which it resides. In vitro studies have indicated that the Legionella protein DrrA post-translationally modifies the GTPase Rab1 by a process called AMPylation. Here we used mass spectrometry to investigate post-translational modifications to Rab1 that occur during infection of host cells by Legionella. Consistent with in vitro studies, DrrA-mediated AMPylation of a conserved tyrosine residue in the switch II region of Rab1 was detected during infection. In addition, a modification to an adjacent serine residue in Rab1 ...

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