Immune Response to Lactobacillus plantarum Expressing Borrelia burgdorferi OspA Is Modulated by the Lipid Modification of the Antigen (original) (raw)

Borrelia burgdorferi Changes Its Surface Antigenic Expression in Response to Host Immune Responses

Infection and Immunity, 2004

The Lyme disease spirochete, Borrelia burgdorferi , causes persistent mammalian infection despite the development of vigorous immune responses against the pathogen. To examine spirochetal phenotypes that dominate in the hostile immune environment, the mRNA transcripts of four prototypic surface lipoproteins, decorin-binding protein A (DbpA), outer surface protein C (OspC), BBF01, and VlsE, were analyzed by quantitative reverse transcription-PCR under various immune conditions. We demonstrate that B. burgdorferi changes its surface antigenic expression in response to immune attack. dbpA expression was unchanged while the spirochetes decreased ospC expression by 446 times and increased BBF01 and vlsE expression up to 20 and 32 times, respectively, under the influence of immune pressure generated in immunocompetent mice during infection. This change in antigenic expression could be induced by passively immunizing infected severe combined immunodeficiency mice with specific Borrelia ant...

Induction of pro- and anti-inflammatory cytokines by Borrelia burgdorferi lipoproteins in monocytes is mediated by CD14

Infection and Immunity, 1999

We previously showed that heat-killed Borrelia burgdorferi spirochetes and lipidated outer surface protein A (L-OspA) stimulated the in vitro production of interleukin-10 (IL-10) in peripheral blood mononuclear cells (PBMC) from uninfected humans and rhesus monkeys (G. Giambartolomei et al., Infect. Immun. 66:2691-2697, 1998). Here we demonstrate that uninfected human peripheral blood monocytes, but not B or T cells, are the cells that transcribe the IL-10 cytokine gene in response to heat-killed B. burgdorferi. B. burgdorferi similarly induced an upregulation of the IL-1␤ and IL-6 cytokine genes in monocytes and the production of IL-10 and IL-6 in culture supernatants of the human monocytic cell line THP-1. Purified L-OspA (but not unlipidated OspA [U-OspA] or U-OspC) also stimulated the production of both cytokines in THP-1 cells in a dosedependent fashion, suggesting that acylation of the OspA protein molecule is required for the production of both anti-and pro-inflammatory cytokines in naive monocytes. A lipohexapeptide that contained the tripalmitoyl-modified cysteine motif (Pam 3 Cys-Hex) of B. burgdorferi lipoproteins but with an arbitrary peptide sequence had the same effect. Monoclonal antibodies (MAbs) MY4 and 60bca, both of which bind to CD14 and are known to block lipopolysaccharide (LPS)-mediated cytokine production, were able to block L-OspAmediated IL-10 and IL-6 cytokine production. In contrast, MAb 26ic, which also binds to CD14 but does not block LPS function, failed to inhibit L-OspA-mediated cytokine production. These data suggest that activation of monocytes and production of both anti-and pro-inflammatory cytokines induced by lipoproteins proceeds via the CD14 receptor. LPS binding protein was not required for OspA-induced cytokine production. Our results demonstrate that pro-and anti-inflammatory cytokines induced by B. burgdorferi lipoproteins in PBMC are produced by monocytes and that lipoprotein and LPS signaling pathways share at least the initial signaling event that involves the CD14 receptor.

Borrelia burgdorferi Resistance to a Major Skin Antimicrobial Peptide Is Independent of Outer Surface Lipoprotein Content

Antimicrobial Agents and Chemotherapy, 2009

We hypothesize a potential role for Borrelia burgdorferi OspC in innate immune evasion at the initial stage of mammalian infection. We demonstrate that B. burgdorferi is resistant to high levels (>200 μg/ml) of cathelicidin and that this antimicrobial peptide exhibits limited binding to the spirochetal outer membrane, irrespective of OspC or other abundant surface lipoproteins. We conclude that the essential role of OspC is unrelated to resistance to this component of innate immunity.

Cholesterol Lipids of Borrelia burgdorferi Form Lipid Rafts and Are Required for the Bactericidal Activity of a Complement-Independent Antibody

Cell Host & Microbe, 2010

Borrelia burgdorferi, the agent of Lyme disease, is unusual as it contains free cholesterol and cholesterol glycolipids. It is also susceptible to complement-independent bactericidal antibodies, such as CB2, a monoclonal IgG1 against outer surface protein B (OspB). We find that the bactericidal action of CB2 requires the presence of cholesterol glycolipids and cholesterol. Ultrastructural, biochemical, and biophysical analysis revealed that the bacterial cholesterol glycolipids exist as lipid raft-like microdomains in the outer membrane of cultured and mouse-derived B. burgdorferi and in model membranes from B. burgdorferi lipids. The order and size of the microdomains are temperature sensitive and correlate with the bactericidal activity of CB2. This study demonstrates the existence of cholesterol-containing lipid raft-like microdomains in a prokaryote, and we suggest that the temperature dependence of B. burgdorferi lipid raft organization may have significant implications in the transmission cycle of the spirochetes which are exposed to a range of temperatures.

The outer surface protein A (OspA) ofBorrelia burgdorferi: A vaccine candidate and bioactive mediator

Infection, 1996

In the search for a suitable vaccine candidate for Lyme borreliosis the principles of protective immunity were studied in a murine model of Borrelia burgdorferilnfection. It was found that the spirochetal outer surface protein A (iipOspA) in its native and recombinant iipidated form induces monospecific immune sera, which in passive transfer experiments protect SCID mice against experimental and tick-borne infection and disease. These and similar findings of independent groups led to the development of a vaccine formulation containing lipOspA. When tested in clinical phase I/lI safety trials the recombinant lipOspA vaccine was shown to be safe, immnnogenic and able to elicit borreliacidal antibodies. At present, clinical phase III efficacy trials are being conducted. B. burgdorferi infection involves the dissemination of the spirochetes from the site of the tick bite, infection of distant organs, and induction of a chronic inflammatory process. Recent studies indicate that the spirochetes may utilize host-derived enzyme systems to increase their virulence/pathogenicity. It was found that lipOspA serves as a surface receptor for the hostderived proteolytic enzyme plasmin(ogen), the central component of the so-called plasminogen activator system. Moreover, it was found that spirochetes are able to activate endothelial cells and blood-derived ieukocytes, such as monocytes/macrophages, B cells and T cells, to express functions and/or secrete molecules, which are known to promote inflammatory responses. Part of these activities were exerted by the isolated lipOspA. The studies indicate an important role of lipOspA, both for the induction of a protective immune response by the host, as well as for the pathogenic processes elicited during B. burgdorferi infection. Recently, a vaccine consisting of freeze-dried whole Borrelia organisms (Bacterin) has been developed for the prevention of disease in dogs [19]. However, it is questionable

Tripalmitoyl-S-Glyceryl-Cysteine-Dependent OspA Vaccination of Toll-Like Receptor 2-Deficient Mice Results in Effective Protection from Borrelia burgdorferi Challenge

Infection and Immunity, 2003

Toll-like receptor 2 (TLR2) is a transmembrane signal transducer for tripalmitoyl-S-glyceryl-cysteine (Pam 3 Cys)-modified lipoproteins, including OspA from the Lyme disease spirochete Borrelia burgdorferi. The Pam 3 Cys modification provides adjuvant activity for inducing humoral responses, suggesting that TLR2 could function as the adjuvant receptor for the OspA vaccine. The importance of TLR2 in the humoral response to OspA was confirmed, because overall levels of immunoglobulin G (IgG) were reduced in TLR2-deficient mice, when compared with those in wild-type mice. However, the levels of production of IgG1 were similar in both mouse strains, and the levels of induction of protective immunity were comparable. Unlipidated OspA was not immunogenic in wild-type or TLR2-deficient mice, indicating the lipid modification was active in the absence of TLR2. These findings indicate that the Pam 3 Cys modification of bacterial lipoprotein has adjuvant properties independent of TLR2 signaling.

Molecular cloning and immunological characterization of a novel linear-plasmid-encoded gene, pG, of Borrelia burgdorferi expressed only in vivo

Infection and Immunity, 1995

Previously we have found that sera from immunocompetent mice infected either naturally by ticks or experimentally with low numbers of Borrelia burgdorferi ZS7 bacteria lack OspA-and OspB-specific antibodies but confer optimal protection on severe combined immunodeficiency mice against challenge with spirochetes (U. E. Schaible, L. Gern, R. Wallich, M. D. Kramer, M. Prester, and M. M. Simon, Immunol. Lett. 36:219-226, 1993). We have now used the latter immune sera to identify new spirochetal structures with relevance for protection from an expression library of the virulent European strain B. burgdorferi ZS7. Here we report the cloning and characterization of a novel lipoprotein, designated pG, the gene for which is located on a 48-kb linear plasmid. Sequence analysis of the pG gene revealed an open reading frame encoding a putative lipoprotein of 196 amino acids with a calculated molecular mass of 22 kDa and a consensus cleavage sequence (Leu-X-Y-Z-Cys) recognized by signal peptidase II. Restriction fragment length polymorphism analyses of pG derived from independent B. burgdorferi isolates from different geographic areas revealed that the gene is species specific, with, however, extensive genotypic heterogeneity. Comparison of the protein sequence of pG with those of other known B. burgdorferi outer surface lipoproteins (OspA to OspF and P27) demonstrated that pG is most related to OspF. Furthermore, the upstream region of pG exhibited extensive sequence homology (>94%) with the ospEF promoter region. Mouse immune sera to recombinant pG did not recognize a corresponding molecule in lysates of in vitro-propagated ZS7 spirochetes. However, experimental or natural infection of mice with ZS7 resulted in the induction of antibodies with reactivity for pG and the potential to delay the development of clinical arthritis. Together with the finding that sera from Lyme disease patients also contain antibodies to pG, our data suggest that the pG gene is preferentially expressed in the mammal environment.

Immunochemical characterization of and isolation of the gene for a Borrelia burgdorferi immunodominant 60-kilodalton antigen common to a wide range of bacteria

Infection and Immunity, 1988

By crossed immunoelectrophoresis and Western blotting (immunoblotting), it was shown that Borrelia burgdorferi expresses the 60-kilodalton Common Antigen (CA) that is cross-reactive with an equivalent antigen in a wide range of remotely related bacteria. B. burgdorferi CA is strongly immunogenic. A B. burgdorferi genomic library was constructed by using a plasmid cloning system. Escherichia coli recombinants were screened for expression of immunodominant B. burgdorferi antigens. One of the recombinant clones expressed the 60-kilodalton CA of B. burgdorferi. The DNA region encoding B. burgdorferi CA was localized on a 2.3-kilobase fragment of the plasmid pKHl. CA may have pathogenetic implications in Lyme borreliosis, since the CA of mycobacteria recently has been shown to play a role in the etiology of experimental autoimmune arthritis. The extensive cross-reactivity of this antigen may account for the low diagnostic specificity of the currently used serological tests in Lyme borreliosis.