title: Modulation of Borrelia burgdorferi stringent response and gene expression during extracellular growth with tick cells.
abstract: Borrelia burgdorferi N40 multiplied extracellularly when it was cocultured with tick cells in L15BS medium, a medium which by itself did not support B. burgdorferi N40 growth. Growth of B. burgdorferi N40 in the presence of tick cells was associated with decreased production of (p)ppGpp, the stringent response global regulator, a fourfold decrease in relA/spoT mRNA, an eightfold net decrease in bmpD mRNA, and a fourfold increase in rpsL-bmpD mRNA compared to growth of B. burgdorferi in BSK-H medium. As a result, the polycistronic rpsL-bmpD mRNA level increased from 3 to 100% of the total bmpD message. These observations demonstrate that there are reciprocal interactions between B. burgdorferi and tick cells in vitro and indicate that the starvation-associated stringent response mediated by (p)ppGpp present in B. burgdorferi growing in BSK-H medium is ameliorated in B. burgdorferi growing in coculture with tick cell lines. These results suggest that this system can provide a useful model for identifying genes controlling interactions of B. burgdorferi with tick cells in vitro when it is coupled with genetic methods to isolate and complement B. burgdorferi mutants.
authors: Department of Microbiology, New York Medical College, Valhalla, New York 10595, USA.
authors: Julia
authors: J
authors: Bugrysheva
authors: Elena Y
authors: EY
authors: Dobrikova
authors: Henry P
authors: HP
authors: Godfrey
authors: Marina L
authors: ML
authors: Sartakova
authors: Felipe C
authors: FC
authors: Cabello
mesh_terms: D000818:Animals; D025065:Borrelia burgdorferi / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D002460:Cell Line; D005110:Extracellular Space; D001277:GTP Pyrophosphokinase / Q000378:metabolism*; D015870:Gene Expression; D015964:Gene Expression Regulation, Bacterial; D011755:Pyrophosphatases / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics*; D013987:Ticks
chemical_list: D012269:Ribosomal Proteins; C034212:ribosomal protein S12; D001277:GTP Pyrophosphokinase; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases