Limits...
Borrelia valaisiana resist complement-mediated killing independently of the recruitment of immune regulators and inactivation of complement components.

Schwab J, Hammerschmidt C, Richter D, Skerka C, Matuschka FR, Wallich R, Zipfel PF, Kraiczy P - PLoS ONE (2013)

Bottom Line: Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum.In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3.Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany.

ABSTRACT
Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B. valaisiana, a genospecies with the potential to cause Lyme disease in Europe as well as in Asia. Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum. Analyzing complement activation, complement components C3, C4 and C6 were deposited on the surface of isolates VS116 and Bv9, and similarly the membrane attack complex was formed on their surface. In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3. While further investigating the protective role of bound complement regulators in mediating complement resistance, we discovered that none of the B. valaisiana isolates analyzed bound complement regulators Factor H, Factor H-like protein 1, C4b binding protein or C1 esterase inhibitor. In addition, B. valaisiana also lacked intrinsic proteolytic activity to degrade complement components C3, C3b, C4, C4b, and C5. Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum. The molecular mechanism utilized by B. valaisiana to inhibit bacteriolysis appears not to involve binding of the key host complement regulators of the alternative, classical, and lectin pathways as already known for serum-resistant Lyme disease or relapsing fever borreliae.

Show MeSH

Related in: MedlinePlus

Serum susceptibility testing of B. valaisiana.A colorimetric growth survival assay was used to investigate susceptibility to human serum of B. valaisiana Bv9, VS116, ZWU3 Ny3, B. garinii G1, and B. burgdorferi LW2. Spirochetes were incubated in either 50% NHS (diamonds) or 50% hiNHS (rectangles) over an incubation period of 9 days at 33°C. Color changes were monitored by measurement of the absorbance at 562/630 nm. All experiments were performed three times with at least three replicates, obtaining very similar results. For clarity, data of a representative experiment are shown. Error bars represent ± SD.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3539980&req=5

pone-0053659-g001: Serum susceptibility testing of B. valaisiana.A colorimetric growth survival assay was used to investigate susceptibility to human serum of B. valaisiana Bv9, VS116, ZWU3 Ny3, B. garinii G1, and B. burgdorferi LW2. Spirochetes were incubated in either 50% NHS (diamonds) or 50% hiNHS (rectangles) over an incubation period of 9 days at 33°C. Color changes were monitored by measurement of the absorbance at 562/630 nm. All experiments were performed three times with at least three replicates, obtaining very similar results. For clarity, data of a representative experiment are shown. Error bars represent ± SD.

Mentions: To further evaluate the serum resistance pattern of B. valaisiana to human complement, three isolates collected from ticks at different geographical locations were incubated in 50% active NHS or in 50% hiNHS for up to 9 days and cell growth was monitored in a colorimetric growth survival assay [47], [48]. Growth of viable spirochetes results in a continuous decrease of the absorbance values due to accumulation of secondary metabolites in the BSK-H medium. As demonstrated in figure 1, growth of B. valaisiana isolate Bv9, B. valaisiana type strain VS116, and serum-sensitive control strain B. garinii G1 when challenged with 50% NHS was completely inhibited as evidenced by only minor changes of absorbance values. Under identical experimental conditions, B. valaisiana ZWU3 Ny3 as well as serum-resistant B. burgdorferi LW2 showed growth in NHS as indicated by continuous decrease of absorbance values. As expected, hiNHS did not affect growth of the five borrelial strains analyzed. In contrast to previous findings, only B. valaisiana strain ZWU3 Ny3 resist complement-mediated killing by human serum.


Borrelia valaisiana resist complement-mediated killing independently of the recruitment of immune regulators and inactivation of complement components.

Schwab J, Hammerschmidt C, Richter D, Skerka C, Matuschka FR, Wallich R, Zipfel PF, Kraiczy P - PLoS ONE (2013)

Serum susceptibility testing of B. valaisiana.A colorimetric growth survival assay was used to investigate susceptibility to human serum of B. valaisiana Bv9, VS116, ZWU3 Ny3, B. garinii G1, and B. burgdorferi LW2. Spirochetes were incubated in either 50% NHS (diamonds) or 50% hiNHS (rectangles) over an incubation period of 9 days at 33°C. Color changes were monitored by measurement of the absorbance at 562/630 nm. All experiments were performed three times with at least three replicates, obtaining very similar results. For clarity, data of a representative experiment are shown. Error bars represent ± SD.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3539980&req=5

pone-0053659-g001: Serum susceptibility testing of B. valaisiana.A colorimetric growth survival assay was used to investigate susceptibility to human serum of B. valaisiana Bv9, VS116, ZWU3 Ny3, B. garinii G1, and B. burgdorferi LW2. Spirochetes were incubated in either 50% NHS (diamonds) or 50% hiNHS (rectangles) over an incubation period of 9 days at 33°C. Color changes were monitored by measurement of the absorbance at 562/630 nm. All experiments were performed three times with at least three replicates, obtaining very similar results. For clarity, data of a representative experiment are shown. Error bars represent ± SD.
Mentions: To further evaluate the serum resistance pattern of B. valaisiana to human complement, three isolates collected from ticks at different geographical locations were incubated in 50% active NHS or in 50% hiNHS for up to 9 days and cell growth was monitored in a colorimetric growth survival assay [47], [48]. Growth of viable spirochetes results in a continuous decrease of the absorbance values due to accumulation of secondary metabolites in the BSK-H medium. As demonstrated in figure 1, growth of B. valaisiana isolate Bv9, B. valaisiana type strain VS116, and serum-sensitive control strain B. garinii G1 when challenged with 50% NHS was completely inhibited as evidenced by only minor changes of absorbance values. Under identical experimental conditions, B. valaisiana ZWU3 Ny3 as well as serum-resistant B. burgdorferi LW2 showed growth in NHS as indicated by continuous decrease of absorbance values. As expected, hiNHS did not affect growth of the five borrelial strains analyzed. In contrast to previous findings, only B. valaisiana strain ZWU3 Ny3 resist complement-mediated killing by human serum.

Bottom Line: Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum.In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3.Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Microbiology and Infection Control, University Hospital of Frankfurt, Frankfurt, Germany.

ABSTRACT
Spirochetes belonging to the Borrelia (B.) burgdorferi sensu lato complex differ in their resistance to complement-mediated killing, particularly in regard to human serum. In the present study, we elucidate the serum and complement susceptibility of B. valaisiana, a genospecies with the potential to cause Lyme disease in Europe as well as in Asia. Among the investigated isolates, growth of ZWU3 Ny3 was not affected while growth of VS116 and Bv9 was strongly inhibited in the presence of 50% human serum. Analyzing complement activation, complement components C3, C4 and C6 were deposited on the surface of isolates VS116 and Bv9, and similarly the membrane attack complex was formed on their surface. In contrast, no surface-deposited components and no aberrations in cell morphology were detected for serum-resistant ZWU3 Ny3. While further investigating the protective role of bound complement regulators in mediating complement resistance, we discovered that none of the B. valaisiana isolates analyzed bound complement regulators Factor H, Factor H-like protein 1, C4b binding protein or C1 esterase inhibitor. In addition, B. valaisiana also lacked intrinsic proteolytic activity to degrade complement components C3, C3b, C4, C4b, and C5. Taken together, these findings suggest that certain B. valaisiana isolates differ in their capability to resist complement-mediating killing by human serum. The molecular mechanism utilized by B. valaisiana to inhibit bacteriolysis appears not to involve binding of the key host complement regulators of the alternative, classical, and lectin pathways as already known for serum-resistant Lyme disease or relapsing fever borreliae.

Show MeSH
Related in: MedlinePlus