Furthermore, it is suggested that multiple strains should be used to fully understand the infection and pathogenic mechanisms involved in Lyme disease manifestations since some invasive strains may possess or express specific virulence factors differentially. Methods Bacterial strains and cell lines B315A4 clones were obtained from the laboratory of Steven Norris at University of Texas, Houston. The N40D10/E9 strain was originally cloned and provided by John Leong at Tufts University Medical School, Boston. Low passage (less than six) B. Selleckchem KPT-330 burgdorferi strains B31 and N40 (from original clone D10/E9)

were grown in Barbour-Stoenner-Kelly-II (BSK-II) medium [112] supplemented with 6% rabbit serum at 33°C. Various mammalian Selleck Fedratinib cell lines for this study were cultured according to recommended conditions originally provided by the suppliers. Vero (monkey kidney epithelial) cells were cultured in RPMI 1640 supplemented with 10% NuSerum IV (BD Biosciences, Franklin Lakes, NJ). EA.hy926 (human endothelial)

cells were cultured in DMEM supplemented with 10% fetal bovine serum (FBS) and 1% HAT nutrient supplement (Invitrogen, Carlsbad, CA). C6 (rat) glial cells were cultured in RPMI 1640 supplemented with 8% FBS. T/C-28a2 (human chondrocyte) cells [69] were cultured in a 1:1 mix of DMEM and Ham’s 12 medium supplemented with 10% FBS. AZD8186 in vitro All mammalian cells were grown at 37°C in 5% CO2 atmosphere. Radioactive labeling of B. burgdorferi B. burgdorferi strains were labeled with 35 S isotope as previously described [38]. Briefly, B. burgdorferi was cultured in BSK-II medium supplemented with 6% rabbit serum and 100 μCi/ml 35 S] -cysteine and -methionine protein labeling mix (Perkin-Elmer, Waltham, MA) at 33°C until the density was between 5 × 107 and 1 × 108 spirochetes per ml. The

bacteria were harvested U0126 order by centrifugation at 5000 × g for 20 minutes, and then washed three times with PBS supplemented with 0.2% BSA. Labeled B. burgdorferi were resuspended in BSK-H medium (Sigma-Aldrich, St. Louis, MO) containing 20% glycerol, with a final spirochete density of 1-2 × 108 per ml, and stored in aliquots at −80°C. Attachment of radiolabeled B. burgdorferi to mammalian cells Binding of B. burgdorferi to mammalian cells was quantified according to procedures described previously [62]. One or two days prior to the assay, mammalian cells were lifted and plated in 96-well break-apart microtiter plates coated with 2 μg/ml Yersinia pseudotuberculosis recombinant purified invasin protein [113]. On the day of the experiment, frozen aliquots of radiolabeled B. burgdorferi were thawed and resuspended in 1.8 ml of BSK-H medium without serum and then incubated for 2 hours at room temperature to allow for physiologic recovery of the bacteria. B. burgdorferi were then diluted 1:3 in 10 mM HEPES, 10 mM glucose, 50 mM NaCl (pH 7.0).