James L. Coleman

Reciprocal upregulation of urokinase plasminogen activator and its inhibitor, PAI‐2, by Borrelia burgdorferi affects bacterial penetration and host‐inflammatory response

The mammalian plasminogen activation system (PAS) is a complex system involved in multiple physiological and pathological processes. Borrelia burgdorferi interacts with certain components of the PAS. Here we further investigate this interaction to determine its effect on bacterial dissemination and host cell migration in vitro. We show that stimulation of monocytic cells with B. burgdorferi induces the transient production and secretion of urokinase plasminogen activator (uPA), shortly followed by its physiological inhibitor, plasminogen activator inhibitor‐2 (PAI‐2). Mono Mac 6 (MM6) cells as well as peripheral blood monocytes enhanced transmigration of B. burgdorferi across a barrier coated with fibronectin mediated by uPA. Moreover, the induction of PAI‐2 or the addition of recombinant PAI‐2 did not have a significant effect on the uPA‐potentiated transmigration of B. burgdorferi. In contrast, the induction of PAI‐2 by B. burgdorferi resulted in significantly diminished invasion by monocytic cells across a reconstituted basement membrane (matrigel), which could be partially restored by treatment with purified uPA. These results show that the PAS plays a twofold role in the pathogenesis of B. burgdorferi infection, both by enhancing bacterial dissemination and by diminishing host‐cell inflammatory migration.

A Bactericidal Monoclonal Antibody Elicits a Change in Its Antigen, OspB of Borrelia burgdorferi, That Can Be Detected by Limited Proteolysis

mAb CB2, directed against outer surface protein B (OspB), causes bacteriolysis of Borrelia burgdorferi in the absence of complement. How this happens is unknown. We examined the effect of mAb binding on OspB tertiary structure by using limited proteolysis to probe changes in protein conformation. Truncated OspB (tOspB) that lacked N-terminal lipid was cleaved by four enzymes: trypsin, endoproteinase Arg-C, endoproteinase Asp-N, and endoproteinase Glu-C. CB2 affected the cleavage by trypsin and Arg-C, but not by AspN or Glu-C. None of the enzymes cleaved CB2 under these conditions. Both trypsin and Arg-C cleaved tOspB near the N-terminus; CB2 slowed the rate of cleavage, but did not affect the identity of the sites cleaved. Irrelevant mAb had no effect, indicating that the effect was specific. CB2 was active against tOspB of strain B31, but not against tOspB of strain BEP4, to which it does not bind, suggesting that binding was required to elicit the effect on cleavage. With trypsin, CB2 showed a maximal effect at 8 mol of tOspB to 1 mol of mAb. At this ratio, not enough CB2 was present to bind all the tOspB; therefore, either CB2 shows turnover or CB2 acts by binding tOspB and effecting a change in this tOspB such that it, in turn, propagates the effect in other molecules of tOspB. Regardless of the mechanism, these data show that CB2 elicits a change in tOspB that can be measured by its reduced susceptibility to protease cleavage.

A role for interleukin-1 in the pathogenesis of Lyme disease.

Summary Interleukin-1 (IL-1) is the major immunoregulatory molecule produced by macrophages in response to a variety of environmental insults including chemicals, phagocytosis, bacteria, and bacterial products. Macrophages stimulated by Borrelia burgdorferi produced large quantities of IL-1 when spirochetes were added to macrophages at a ratio of 10 spirochetes per macrophage. The release of IL-1 was dose dependent: a single spirochete per macrophage was sufficient to produce significant quantities of IL-1. Spirochetal lipopolysaccharide was not required for this activity in that polymyxin B in the spirochete-macrophage culture had no effect on IL-1 production. Normal murine fibroblasts cultured with this IL-1 were shown to have an increased rate of DNA synthesis and an increase in secreted collagenase. IL-1 was found in joint fluids from Lyme disease patients. When IL-1 was injected intradermally into the backs of rabbits, the injection sites became indurated, erythematous, and warm to the touch after 4 hrs and annular lesions much like those of erythema chronicum migrans were seen in some animals after 24 hrs. B. burgdorferi is a powerful inducer for IL-1 in vitro , and it is reasonable to presume that it acts similarly in Lyme disease patients. Our results suggest that IL-1 in turn, may play a role in many of the clinical manifestations of Lyme disease.

Isolation of the outer envelope from Borrelia burgdorferi

Borrelia burgdorferi consists of an inner protoplasmic cylinder, containing the genome and cytoplasmic elements, surrounded by a number of axial filaments, all completely encased within a multiple-layered outer envelope structure (OE). In this study, a sodium dodecyl sulfate-mediated technique was used to isolate the OE from Borrelia burgdorferi in an attempt to better understand this structure in terms of its antigenic reactivity to Lyme disease patient sera. Electron microscopic evidence suggested that the OE product was relatively free of other spirochete cellular components. SDS-PAGE analysis indicated that the electrophoretic pattern of the OE was consistent with that of the remaining protoplasmic cylinder (PC) and whole spirochete controls. Antigenic determinants in the OE were recognized by sera from Lyme disease patients in Western blots. Chemical analysis of the OE revealed a composition of 45.90% protein, 50.75% lipid and 3.33% carbohydrate. The OE comprised 16.5% by lyophilized dry weight of the whole spirochete. Antigenic determinants located within or associated with this structure are likely to play a significant role in the development of immunity in the infected host.

Clinical and geographic characteristics of Lyme disease in New York.

The clinical and geographic characteristics of 679 patients who met the clinical definition of Lyme disease and who had antibody titers of greater than or equal to 1: 128 to Borrelia burgdorferi for a two year period, 1983-1984, are described. Males outnumbered females 60% to 40% for the two year period and nearly half of all cases were children and young adults nineteen years old or younger. Forty percent of the patients reported single or multiple tick bites prior to the onset of illness and tick bites were clustered in the summer months. Skin lesions (ECM) were reported in 63% of all the patients. Joint involvement as the only manifestation of Lyme disease was reported in 21% and 22% of all the patients in 1983 and 1984 respectively. A 2: 1 ratio of males to females was noted on this subgroup and 63% of these were 19 years old or less. Onset of joint manifestations were most frequent in the last three months of the year. Neurological manifestations were noted in 20% of the patients with facial palsy being the most frequent. Twenty nine patients had neurological disorders as the only manifestation of Lyme disease. Cardiovascular symptoms were reported in 26 patients (4%). The secondary manifestations of Lyme disease were of summer and early fall onset. Lyme disease in New York is restricted to suburbs north of New York City in Westchester County, and in suburbs to the east of New York City in Suffolk County, Long Island. Incidence for the two year period can range from 0.01 cases per 1000 in some communities to 28 cases per 1000 in highly endemic areas.

Borrelia burgdorferi lipopolysaccharide and its role in the pathogenesis of lyme disease

Lipopolysaccharides (LPS) are a constitutive part of the outer wall of gram negative bacteria. Because many of the symptoms of Lyme disease could be explained by a spirochetal LPS we have subjected Borrelia burgdorferi to standard LPS extraction techniques which yielded a LPS which accounted for 1.5-4% of the dry weight. The LPS was very similar to classical gram negative bacterial LPS both chemically and in its biological activities which included pyrogenicity, mitogenicity for lymphocytes and the induction of Interleukin 1 production by macrophages. In addition, the LPS produced an acute inflammatory reaction when injected intradermally into rabbit skin. It could also prepare a skin site for the production of the local Shwartzman reaction. These results show that the Lyme disease spirochete contains a hitherto unknown LPS that is biologically active in vitro and in vivo. It is likely that this molecule plays an important role in the pathogenesis of Lyme disease.

An IgE response to spirochete antigen in patients with lyme disease

Most but not all Lyme disease patients produce specific IgE antibodies to Borrelia burgdorferi. Development of IgE antibodies paralleled that of other immunologic classes and appeared to be directed against a polypeptide with a molecular weight of 41,000. Total serum IgE levels in Lyme disease patients were usually within the normal range in all stages of the disease. However, highly elevated total serum IgE in certain patients were not correlated to any particular disease stage nor to specific antibody titers. Spirochetes and spirochetal sonicates in high concentration induced release of histamine from basophils derived from both patients and controls. At lower antigen concentrations, histamine release could be induced only from basophils derived from patients. Synovial fluids from patients with Lyme arthritis contained IgE but only negligible amounts of histamine.