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Lymphoadenopathy during lyme borreliosis is caused by spirochete migration-induced specific B cell activation.

Tunev SS, Hastey CJ, Hodzic E, Feng S, Barthold SW, Baumgarth N - PLoS Pathog. (2011)

Bottom Line: The induced B cell response does appear, however, to be largely antigen-specific.Finally, neither the quality nor the magnitude of the B cell responses was altered in mice lacking the Toll-like receptor adaptor molecule MyD88.Together, these findings suggest a novel evasion strategy for B. burgdorferi: subversion of the quality of a strongly induced, potentially protective borrelia-specific antibody response via B. burdorferi's accumulation in lymph nodes.

View Article: PubMed Central - PubMed

Affiliation: Center for Comparative Medicine, University of California Davis, Davis, California, United States of America.

ABSTRACT
Lymphadenopathy is a hallmark of acute infection with Borrelia burgdorferi, a tick-borne spirochete and causative agent of Lyme borreliosis, but the underlying causes and the functional consequences of this lymph node enlargement have not been revealed. The present study demonstrates that extracellular, live spirochetes accumulate in the cortical areas of lymph nodes following infection of mice with either host-adapted, or tick-borne B. burgdorferi and that they, but not inactivated spirochetes, drive the lymphadenopathy. The ensuing lymph node response is characterized by strong, rapid extrafollicular B cell proliferation and differentiation to plasma cells, as assessed by immunohistochemistry, flow cytometry and ELISPOT analysis, while germinal center reactions were not consistently observed. The extrafollicular nature of this B cell response and its strongly IgM-skewed isotype profile bear the hallmarks of a T-independent response. The induced B cell response does appear, however, to be largely antigen-specific. Use of a cocktail of recombinant, in vivo-expressed B. burgdorferi-antigens revealed the robust induction of borrelia-specific antibody-secreting cells by ELISPOT. Furthermore, nearly a quarter of hybridomas generated from regional lymph nodes during acute infection showed reactivity against a small number of recombinant Borrelia-antigens. Finally, neither the quality nor the magnitude of the B cell responses was altered in mice lacking the Toll-like receptor adaptor molecule MyD88. Together, these findings suggest a novel evasion strategy for B. burgdorferi: subversion of the quality of a strongly induced, potentially protective borrelia-specific antibody response via B. burdorferi's accumulation in lymph nodes.

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Lymph nodes of B. burgdorferi-infected mice contain large numbers borrelia-specific B cells.Shown are the results of three independent hybridoma fusion experiments. (A) Shown are stacked bars with the total number of antibody-secreting cells (black) and the number of lines generating B. burgdorferi-specific antibody as assessed by ELISA with four recombinant B. Burgdorferi antigens. Cells for the fusion were from indicated lymph nodes and times after infection with host-adapted spirochetes. (B) Indicated are the Ig-isotype distribution among all B. burgdorferi-specific hybridoma lines generated.
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ppat-1002066-g006: Lymph nodes of B. burgdorferi-infected mice contain large numbers borrelia-specific B cells.Shown are the results of three independent hybridoma fusion experiments. (A) Shown are stacked bars with the total number of antibody-secreting cells (black) and the number of lines generating B. burgdorferi-specific antibody as assessed by ELISA with four recombinant B. Burgdorferi antigens. Cells for the fusion were from indicated lymph nodes and times after infection with host-adapted spirochetes. (B) Indicated are the Ig-isotype distribution among all B. burgdorferi-specific hybridoma lines generated.

Mentions: The ELISPOT results suggested that a significant fraction of the induced B cell response was specific and directed against B. burgdorferi. However, given that we probed with only some of the many other Borrelia proteins that are potentially expressed selectively in vivo, assessment of the relative contribution of the specific over the non-specific response was difficult. Therefore, another series of experiments was conducted in which hybridomas were generated from the regional lymph nodes to assess the fraction of hybridomas directed against Borrelia-specific antigens with an expanded list of recombinant Borrelia proteins. Three successful fusions were conducted, including one on lymph nodes at day 8 of infection, and two on day 18. The overall results from these three fusions were similar (Figure 6A). Initial screening of roughly 1000 wells per fusion identified between 150–350 wells that showed antibody-secretion. Further screening of the antibody-secreting lines indicated that between 14–24% of the hybridoma lines generated antibodies that could be identified to react against an expanded list of recombinant Borrelia antigens (DbpA, OspC, Arp, BmpA, P23, P29, P32, P61 (defined in Supplemental Table S1) [41] and/or Borrelia lysate from cultured spirochetes.


Lymphoadenopathy during lyme borreliosis is caused by spirochete migration-induced specific B cell activation.

Tunev SS, Hastey CJ, Hodzic E, Feng S, Barthold SW, Baumgarth N - PLoS Pathog. (2011)

Lymph nodes of B. burgdorferi-infected mice contain large numbers borrelia-specific B cells.Shown are the results of three independent hybridoma fusion experiments. (A) Shown are stacked bars with the total number of antibody-secreting cells (black) and the number of lines generating B. burgdorferi-specific antibody as assessed by ELISA with four recombinant B. Burgdorferi antigens. Cells for the fusion were from indicated lymph nodes and times after infection with host-adapted spirochetes. (B) Indicated are the Ig-isotype distribution among all B. burgdorferi-specific hybridoma lines generated.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3102705&req=5

ppat-1002066-g006: Lymph nodes of B. burgdorferi-infected mice contain large numbers borrelia-specific B cells.Shown are the results of three independent hybridoma fusion experiments. (A) Shown are stacked bars with the total number of antibody-secreting cells (black) and the number of lines generating B. burgdorferi-specific antibody as assessed by ELISA with four recombinant B. Burgdorferi antigens. Cells for the fusion were from indicated lymph nodes and times after infection with host-adapted spirochetes. (B) Indicated are the Ig-isotype distribution among all B. burgdorferi-specific hybridoma lines generated.
Mentions: The ELISPOT results suggested that a significant fraction of the induced B cell response was specific and directed against B. burgdorferi. However, given that we probed with only some of the many other Borrelia proteins that are potentially expressed selectively in vivo, assessment of the relative contribution of the specific over the non-specific response was difficult. Therefore, another series of experiments was conducted in which hybridomas were generated from the regional lymph nodes to assess the fraction of hybridomas directed against Borrelia-specific antigens with an expanded list of recombinant Borrelia proteins. Three successful fusions were conducted, including one on lymph nodes at day 8 of infection, and two on day 18. The overall results from these three fusions were similar (Figure 6A). Initial screening of roughly 1000 wells per fusion identified between 150–350 wells that showed antibody-secretion. Further screening of the antibody-secreting lines indicated that between 14–24% of the hybridoma lines generated antibodies that could be identified to react against an expanded list of recombinant Borrelia antigens (DbpA, OspC, Arp, BmpA, P23, P29, P32, P61 (defined in Supplemental Table S1) [41] and/or Borrelia lysate from cultured spirochetes.

Bottom Line: The induced B cell response does appear, however, to be largely antigen-specific.Finally, neither the quality nor the magnitude of the B cell responses was altered in mice lacking the Toll-like receptor adaptor molecule MyD88.Together, these findings suggest a novel evasion strategy for B. burgdorferi: subversion of the quality of a strongly induced, potentially protective borrelia-specific antibody response via B. burdorferi's accumulation in lymph nodes.

View Article: PubMed Central - PubMed

Affiliation: Center for Comparative Medicine, University of California Davis, Davis, California, United States of America.

ABSTRACT
Lymphadenopathy is a hallmark of acute infection with Borrelia burgdorferi, a tick-borne spirochete and causative agent of Lyme borreliosis, but the underlying causes and the functional consequences of this lymph node enlargement have not been revealed. The present study demonstrates that extracellular, live spirochetes accumulate in the cortical areas of lymph nodes following infection of mice with either host-adapted, or tick-borne B. burgdorferi and that they, but not inactivated spirochetes, drive the lymphadenopathy. The ensuing lymph node response is characterized by strong, rapid extrafollicular B cell proliferation and differentiation to plasma cells, as assessed by immunohistochemistry, flow cytometry and ELISPOT analysis, while germinal center reactions were not consistently observed. The extrafollicular nature of this B cell response and its strongly IgM-skewed isotype profile bear the hallmarks of a T-independent response. The induced B cell response does appear, however, to be largely antigen-specific. Use of a cocktail of recombinant, in vivo-expressed B. burgdorferi-antigens revealed the robust induction of borrelia-specific antibody-secreting cells by ELISPOT. Furthermore, nearly a quarter of hybridomas generated from regional lymph nodes during acute infection showed reactivity against a small number of recombinant Borrelia-antigens. Finally, neither the quality nor the magnitude of the B cell responses was altered in mice lacking the Toll-like receptor adaptor molecule MyD88. Together, these findings suggest a novel evasion strategy for B. burgdorferi: subversion of the quality of a strongly induced, potentially protective borrelia-specific antibody response via B. burdorferi's accumulation in lymph nodes.

Show MeSH
Related in: MedlinePlus