Project description:Transfer RNA (tRNA) modifications play a crucial role in maintaining translational fidelity and efficiency, and they may function as regulatory elements in stress response and virulence. Despite their pivotal roles, a comprehensive mapping of tRNA modifications and their associated synthesis genes is still limited, with a predominant focus on free-living bacteria. In this study, we employed a multidisciplinary approach, incorporating comparative genomics, mass spectrometry, and next-generation sequencing, to predict the set of tRNA modification genes responsible for tRNA maturation in two intracellular pathogens—Bartonella henselae Houston I and Bartonella quintana Toulouse, which are causative agents of cat-scratch disease and trench fever, respectively. This analysis presented challenges, particularly because of host RNA contamination, which served as a potential source of error. However, our approach predicted 26 genes responsible for synthesizing 23 distinct tRNA modifications in B. henselae and 22 genes associated with 23 modifications in B. quintana. Notably, akin to other intracellular and symbiotic bacteria, both Bartonella species have undergone substantial reductions in tRNA modification genes, mostly by simplifying the hypermodifications present at positions 34 and 37. B. quintana exhibited the additional loss of four modifications and these were linked to examples of gene decay, providing snapshots of reductive evolution.
Project description:Myeloid Angiogenic Cells (MACs) were infected with the intracellular, bacterial pathogen Bartonella henselae (B.h.). Infected cells were seeded onto Matrigel coated plates. While uninfected cells showed no phenotypic changes and died over time, infected cells showed strong phenotypic changes and developed into complex 2D chord networks over the course of long term culture (eg 49d). To examine the changes in gene expression associated with the development of the B.h.dependent chord formation phenotype, RNA was isolated from MACs shortly after isolation (d4) and from cells of the chord structures (+B.h. Matrigel). As primary endothelial cells are also know to form chord networks when cultured on Matrigel, a sample of human umbilical vein endothelial cells (HUVECs) cultured on Matrigel for 12hr was also included in the analysis as a control.
Project description:Myeloid Angiogenic Cells (MACs) were infected with the intracellular, bacterial pathogen Bartonella henselae (B.h.). Infected cells were seeded onto Matrigel coated plates. While uninfected cells showed no phenotypic changes and died over time, infected cells showed strong phenotypic changes and developed into complex 2D chord networks over the course of long term culture (eg 49d). To examine the changes in gene expression associated with the development of the B.h.dependent chord formation phenotype, RNA was isolated from MACs shortly after isolation (d4) and from cells of the chord structures (+B.h. Matrigel). As primary endothelial cells are also know to form chord networks when cultured on Matrigel, a sample of human umbilical vein endothelial cells (HUVECs) cultured on Matrigel for 12hr was also included in the analysis as a control. myeloid angiogenic cells (MACs) from three donors were compared d4 after isolation with MACs infected with Bartonella henselae and cultured on Matrigel coated plates for up to 49 days, 1 sample from human umbilical cord vein endothelial cells (HUVECs) cultured for 12hr on Matrigel coated plates were also included as a control.
Project description:The genomic diversity of 38 Bartonella henselae isolates was studied by comparative genomic hybridizations. In addition, the effect of growth time (5 or 10 days) was studied for 5 strains.
