Borrelia burgdorferi and the macrophage: routine annihilation but occasional haven?

Borrelia burgdorferi, the agent for Lyme disease, has a typical pattern of bacterial interaction with phagocytes: attachment, stimulation o f release o f inflammatory mediators and, in most cases, ingestion and killing. Spirochetes are killed extracellulorly by antibody plus complement via the classical pathway, as well as by phagocytes through apparently nonoxidative means. Yet rare persistent spirochetes (mutants?) have been identified both in patients' tissues and in cells grown in vitro. Ruth Montgomery and Stephen Malawista here ask: are some Borrelia wolves in sheeps' clothing, evading macrophage anti-microbial action?

Exploitation of interleukin-8-induced neutrophil chemotaxis by the agent of human granulocytic ehrlichiosis

The agent of human granulocytic ehrlichiosis (HGE) is an obligate intracellular bacterium with a tropism for neutrophils; however, the mechanisms of bacterial dissemination are not yet understood. Interleukin-8 (IL-8) is a chemokine that induces neutrophil migration to sites of infection for host defense against pathogens. We now show that HGE bacteria, and the HGE-44 protein, induce IL-8 secretion in a promyelocytic (HL-60) cell line that has been differentiated along the neutrophil lineage with retinoic acid and in neutrophils. Infected HL-60 cells also demonstrate upregulation of CXCR2, an IL-8 receptor, but not CXCR1. Human neutrophils migrate towards Ehrlichia sp.-infected cells in a chemotaxis chamber assay, and this movement can be blocked with antibodies to IL-8. Finally, immunocompetent and severe combined immunodeficient mice administered CXCR2 antisera, and CXCR2(-/-) mice that lack the human IL-8 receptor homologue, are much less susceptible to granulocytic ehrlichiosis than are control animals. These results demonstrate that HGE bacteria induce IL-8 production by host cells and, paradoxically, appear to exploit this chemokine to enhance infection.

Inhibition of Borrelia burgdorferi-tick interactions in vivo by outer surface protein A antibody

Borrelia burgdorferi outer surface protein (Osp) A is preferentially expressed by spirochetes in the Ixodes scapularis gut and facilitates pathogen-vector adherence in vitro. Here we examined B. burgdorferi-tick interactions in vivo by using Abs directed against OspA from each of the three major B. burgdorferi sensu lato genospecies: B. burgdorferi sensu stricto, Borrelia afzelii, and Borrelia garinii. Abs directed against B. burgdorferi sensu stricto (isolate N40) destroy the spirochete and can protect mice from infection. In contrast, antisera raised against OspA from B. afzelii (isolate ACA-1) and B. garinii (isolate ZQ-1) bind to B. burgdorferi N40 but are not borreliacidal against the N40 isolate. Our present studies assess whether these selected OspA Abs interfere with B. burgdorferi-tick attachment in a murine model of Lyme disease with I. scapularis. We examined engorged ticks that had fed on B. burgdorferi N40-infected scid mice previously treated with OspA (N40, ACA-1, ZQ-1, or mAb C3.78) or control Abs. OspA-N40 antisera or mAb C3.78 destroyed B. burgdorferi N40 within the engorged ticks. In contrast, treatment of mice with OspA-ACA-1 and OspA-ZQ-1 antisera did not kill B. burgdorferi N40 within the ticks but did effectively interfere with B. burgdorferi-I. scapularis adherence, thereby preventing efficient colonization of the vector. These studies show that nonborreliacidal OspA Abs can inhibit B. burgdorferi attachment to the tick gut, highlighting the importance of OspA in spirochete-arthropod interactions in vivo.

Murine Lyme disease: no evidence for active immune down-regulation in resolving or subclinical infection

Macrophages in vitro rapidly ingest and kill Borrelia burgdorferi, yet some spirochetes in vivo may survive in the host and lead to complications of Lyme disease. One strategy for such survival may be the down-regulation of the immune system. To test this, we evaluated the degree of macrophage activation in a site of active disease-the heart-by examining cytokine expression in murine macrophages from control and B. burgdorferi-infected animals. Using double-label immunofluorescent staining in situ, we showed that infiltrating macrophages in infected hearts produce interleukin (IL)-1. By semiquantitative reverse transcription-polymerase chain reaction analysis, increased levels of mRNA were measured for the proinflammatory cytokines IL-1, tumor necrosis factor-alpha, and IL-12 during peak and resolving disease. No increases in the anti-inflammatory cytokines IL-10 and transforming growth factor-beta were detected. In an infected site without active disease--the peritoneal cavity--no increases in levels of proinflammatory or anti-inflammatory cytokines were detected in local macrophages. Thus, there is no evidence of pressure toward the down-regulation of inflammatory activity in the regions tested.

Resolution of Lyme arthritis, acute or prolonged: a new look

I have presented a paradigm for the pathogenesis and resolution of Lyme arthritis founded upon the clinical facts that describe its natural history, and centered about a process of intermittent immune recognition of what may sometimes be an array of antigenic variants. The model applies both to acute and to prolonged (chronic) disease. If it proves to be correct, it represents a variation of the struggle between parasite and host that is probably not limited to Lyme disease.

Random locomotion and chemotaxis of human blood polymorphonuclear leukocytes from a patient with leukocyte adhesion deficiency-1: normal displacement in close quarters via chimneying

The beta2 integrins are known to be important in the motile function of leukocytes in general and in the adhesive response to inflammatory stimuli in particular. In the current study, under direct microscopic observation with concomitant time-lapse video recording, we examined the locomotion of human blood PMN from a patient with Leukocyte Adhesion Deficiency-1 (LAD), a disorder in which beta2 integrins on the cell surface are markedly deficient in number or function. In thin slide preparations such that the leukocytes were somewhat compressed between slide and cover slip, PMNLAD exhibited normal random locomotion and chemotaxis, apparently by using the opposing surfaces to generate the force for locomotion (chimneying). In thicker preparations, an adherence deficit was evident, but chemotaxis still occurred, even by PMNLAD anticoagulated in EDTA. Consistent with the paucity of beta2 integrins on the surface of the PMNLAD was their failure to aggregate in the presence of antibodies to beta2 integrins, even when they had been brought together by chemotaxis. We relate these findings to the reported independence from integrins of PMN in the lung vasculature in LAD, as well as in certain experimental conditions.

Geographic clustering of an outer surface protein A mutant of Borrelia burgdorferi. Possible implications of multiple variants for Lyme disease persistence

DNA sequences encoding full-length outer surface protein (Osp) A were amplified from four joint fluid samples over 4.5 months from a patient with chronic Lyme arthritis, with a variant from wild type only found in sample 3. Rather than a mutation in vivo, these findings suggested a mixed infection in which BORRELIA: containing the wild-type and mutant ospA were waxing and waning in the patient's joint. If so, we reasoned that the mutant should be present in the community. We therefore took the novel epitope resulting from the mutation, expressed as a fusion protein in Escherichia coli, and performed Western blots on 80 high-titred stored sera; however, all except that of our index patient were negative. We then collected 36 stored sera from patients with Lyme disease residing within 10 miles of where the index patient had lived. An additional two sera from this circumscribed area were positive (P = 0.038). These findings show that results from single samples can be misleading, and suggest that the OspAs expressed in force late in Lyme arthritis are the same ones introduced initially into the host. Moreover, they allow a speculative mechanism for disease persistence not previously considered, in which antigenically distinct B. burgdorferi variant proteins present themselves serially to the immune system.

Analysis of the PKC-gamma-related immunocrossreactive region of a novel leukocyte protein gamma-rp

The newly discovered gamma-PKC-related-protein of human leukocytes (gamma-rp) crossreacts with a polyclonal antibody preparation originally designed to be specific for PKC-gamma (gammaMb-Ab). As this antibody is currently the only suitable probe for gamma-rp, we sought to characterize the binding of the two proteins. We determined that the gamma Mg-Ab does not recognize the native form of gamma-rp. However, with denaturing immunoblots of gamma-rp, we found that 1) the crossreactive gamma-rp epitope differs somewhat from that of classic rat brain PKC-gamma, but probably only to the degree of the rat/human PKC species difference; 2) the previously reported doublet bands of gamma-rp represent a single protein with cell-stimulus inducible modifications; 3) antibodies present in the gammaMg-Ab pool bind to two separate sites within the gamma-rp epitope; 4) access to one binding site is conformationally restricted, even after protein denaturation; 5) agonist-induced modification of gamma-rp does not significantly affect the total amount of gamma Mg-Ab that it can bind, but 6) does significantly affect the rate of antibody binding to one site. This investigation defines the appropriate experimental use of our antibody, and the significance of these findings for the future study and cloning of gamma-rp is discussed.

[Functions of neutrophil motility of human blood: locomotion and chemotaxis in simplified systems]

Polymorphonuclear leukocytes (PMN, granulocytes) employ their plasma membranes and subjacent microfilament-rich peripheral cytoplasm for such motile functions as adherence and spreading, random locomotion, chemotaxis (directed locomotion), and phagocytosis. All of these functions are preserved in certain anucleate, granule-poor, cytoplasmic fragments (cytoplasts) derived from PMN. Thus, the sensing, transduncing, and effector capacities involved in these functions remain integrated without control from nuclei or from the other cellular organelles left behind when the cytoplast forms. More recently, we have begun to examine in intact PMN the role of divalent cations, which have been thought to be essential for motile function of leukocytes in general, and for the function of critical adhesion molecules in particular. In slide preparations under direct microscopic observation, EDTA (10 mM; to chelate divalent cations) did not impair either random locomotion or chemotaxis, nor did specific antibodies to beta-2 (CD 18) integrins or to other PMN integrins. Motile behavior appeared to benefit from the close approximation of slide and coverslip ("chimneying"). Thus, in "close quarters", PMN can generate the force for locomotion even when adhesion molecules are lacking or disabled. We relate these findings to the reported independence from integrins of PMN in certain experimental and diseases states.

A vaccine consisting of recombinant Borrelia burgdorferi outer-surface protein A to prevent Lyme disease. Recombinant Outer-Surface Protein A Lyme Disease Vaccine Study Consortium

BACKGROUND

Lyme disease is a multisystem inflammatory disease caused by infection with the tick-borne spirochete Borrelia burgdorferi and is the most common vector-borne infection in the United States. We assessed the efficacy of a recombinant vaccine consisting of outer-surface protein A (OspA) without adjuvant in subjects at risk for Lyme disease.

METHODS

For this double-blind trial, 10,305 subjects 18 years of age or older were recruited at 14 sites in areas of the United States where Lyme disease was endemic; the subjects were randomly assigned to receive either placebo (5149 subjects) or 30 microg of OspA vaccine (5156 subjects). The first two injections were administered 1 month apart, and 7515 subjects also received a booster dose at 12 months. The subjects were observed for two seasons during which the risk of transmission of Lyme disease was high. The primary end point was the number of new clinically and serologically confirmed cases of Lyme disease.

RESULTS

The efficacy of the vaccine was 68 percent in the first year of the study in the entire population and 92 percent in the second year among the 3745 subjects who received the third injection. The vaccine was well tolerated. There was a higher incidence of mild, self-limited local and systemic reactions in the vaccine group, but only during the seven days after vaccination. There was no significant increase in the frequency of arthritis or neurologic events in vaccine recipients.

CONCLUSIONS

In this study, OspA vaccine was safe and effective in the prevention of Lyme disease.

An apparently novel protein of human leukocytes, reactive with an antibody to protein kinase C-gamma, is rapidly modified upon cell activation: initial characterization in neutrophils and their cytoplasts

On immunoblots of human neutrophil cytoplasts (U-CYT), a previously undescribed 97 kDa protein was revealed by intense and selective reaction with an antibody that was initially raised to recognize PKC-gamma. Denoted "gamma-rp" for gamma-related protein, this acidic cytosolic protein somewhat resembled the classic forms of PKC in several biochemical respects. Appearing as a doublet on low-percentage SDS-PAGE gels, both its mobility and staining pattern were rapidly altered by treatment of U-CYT with either phorbol ester or chemotactic peptide. Whole neutrophil gamma-rp was detectable only after TCA precipitation of intact cells. It was also detectable in human platelets, lymphocytes, and neutrophil-like differentiated HL60 cells, but not in fibroblasts, erythrocytes, monocytes, or monocyte-like differentiated HL60 cells. Our data suggest that gamma-rp merits further study as a potential participant in cellular activation, and as a possible structural or functional relative of PKC.

Random locomotion and chemotaxis of human blood polymorphonuclear leukocytes (PMN) in the presence of EDTA: PMN in close quarters require neither leukocyte integrins nor external divalent cations

Divalent cations are thought essential for motile function of leukocytes in general, and for the function of critical adhesion molecules in particular. In the current study, under direct microscopic observation with concomitant time-lapse video recording, we examined the effects of 10 mM EDTA on locomotion of human blood polymorphonuclear leukocytes (PMN). In very thin slide preparations, EDTA did not impair either random locomotion or chemotaxis; motile behavior appeared to benefit from the close approximation of slide and coverslip ("chimneying"). In preparations twice as thick, PMN in EDTA first exhibited active deformability with little or no displacement, then rounded up and became motionless. However, on creation of a chemotactic gradient, the same cells were able to orient and make their way to the target, often, however, losing momentarily their purchase on the substrate. In either of these preparations without EDTA, specific antibodies to beta2 integrins did not prevent random locomotion or chemotaxis, even when we added antibodies to beta1 and alphavbeta3 integrins and to integrin-associated protein, and none of these antibodies added anything to the effects of EDTA. In the more turbulent environment of even more media, effects of anti-beta2 integrins became evident: PMN still could locomote but adhered to substrate largely by their uropods and by uropod-associated filaments. We relate these findings to the reported independence from integrins of PMN in certain experimental and disease states. Moreover, we suggest that PMN locomotion in close quarters is not only integrin-independent, but independent of external divalent cations as well.

Chemotaxis by human neutrophils and their cytokineplasts treated with inhibitors of nitric oxide synthase: no suppression of orientation or trajectory

Inhibitors of nitric oxide (NO) synthase are reported to inhibit both the adherence of polymorphonuclear leukocytes (PMN) to substrate and chemotaxis (directed locomotion) of PMN as determined in Boyden chamber assays. In the current study, we examined both human blood PMN and granule-poor motile cytoplasts derived from them (cytokineplasts, CKP), under direct microscopic observation with concomitant time-lapse video recording, for their ability to respond chemotactically to an erythrocyte destroyed by laser microirradiation. In this system we can observe directly and continuously the orientation and trajectory of PMN before, during, and after establishment of a chemotactic gradient. For both PMN and CKP we employed three different inhibitors of NO synthase (N(omega)-methyl-L-arginine, N-iminoethyl-L-ornithine, and diphenyleneiodonium) in at least twice the concentrations employed to inhibit chemotaxis of PMN in Boyden chambers or killing of bacteria in CKP. Although small differences in adhesion might not have been appreciated, treated PMN and CKP were each indistinguishable from untreated controls in their ability to orient in a newly created chemotactic gradient and in their trajectories toward the chemotactic target.

Microbial killing by human neutrophil cytokineplasts: similar suppressive effects of reversible and irreversible inhibitors of nitric oxide synthase

Employing anucleate, granule-poor, motile fragments from human blood neutrophils (cytokineplasts; CKP), we previously provided evidence for a new staphylococcal killing pathway for human neutrophils involving reactive nitrogen intermediates: the NO synthase inhibitor N(omega)-monomethyl-L-arginine (NMMA), an analogue of L-arginine (L-Arg), substantially decreased the killing capacity of CKP for Staphylococcus aureus (Staph), an effect reversible by excess L-Arg but not D-Arg. We have extended these findings to two irreversible NO synthase inhibitors: the first, N-iminoethyl-L-ornithine (L-NIO), is an L-Arg analogue; the other, diphenyleneiodonium (DPI), is not. After 60 min of incubation with bacteria, despite having taken up somewhat fewer staphylococci than did controls, cytoplasts treated with NO synthase inhibitors had many more live, CKP-associated bacteria: for NMMA, 6.9 times more (40.0% of the inoculum vs. 5.8%; n = 8, P = 0.003); for L-NIO, 3.6 times more (25.5 vs. 7%; n = 4, P = 0.004); for DPI, 5.8 times more (37.4 vs. 6.4%; n = 7, P = 0.002). Results were similar after only 20 min of incubation. In two experiments in which the Gram-negative bacterium, Serratia marcescens, was employed instead of Staph, the results were again similar. In contrast, killing of either bacterium by intact neutrophils (PMN) was not inhibited by NMMA, by L-NIO, or by DPI, a failure most likely attributable to their granule content. The irreversible inhibitors of NO synthase will be especially useful in analyzing particular effects on CKP employed in multicellular systems.

Entry of Borrelia burgdorferi into macrophages is end-on and leads to degradation in lysosomes

The Lyme disease spirochete, Borrelia burgdorferi, is ingested rapidly by mouse macrophages in vitro. Spirochetes attach by their ends and become progressively coiled as they move deeper into cells. From the earliest measurements, spirochetes colocalize with a marker of endosomes and lysosomes, and degradation of spirochetes occurs within lysosomes.

Paradoxical effects of colchicine on the activation of human neutrophilis by chemotactic factors and inflammatory microcrystal

Neutrophil activation by chemotactic factors and by inflammatory microcrystals is accompanied by increases in protein tyrosine phosphorylation and by the activation of the NADPH oxidase. The addition of colchicine inhibited both responses induced by triclinic monosodium urate or calcium pyrophosphate crystals. On the other hand, colchicine enhanced the tyrosine phosphorylation of specific protein in neutrophils stimulated by chemotactic factor and augmented the production of superoxide anions induced by these same agonists. The effects of colchicine were shared by other anti-microtubule agents (nocodazole and vinblastine) but not by its inactive analogue beta-lumicolchicine, trimethylcolchicinic acid, indomethacin, or phenylbutazone. Furthermore, the (enhancing as well as inhibitory) effects of colchicine on tyrosine phosphorylation and superoxide anion production were reversed by taxol. Finally, in human cytoplasts colchicine again inhibited microcrystal-stimulated tyrosine phosphorylation but did not change chemotactic factor-stimulated phosphorylation. These data strongly support the hypothesis that microtubule-related mechanisms are involved in the modulation of the tyrosine phosphorylation response in human neutrophils, and suggest that a relationship may exist between the augmentation of tyrosine phosphorylation and of the stimulation of the NADPH oxidase induced by chemotactic factors.

Direct demonstration of antigenic substitution of Borrelia burgdorferi ex vivo: exploration of the paradox of the early immune response to outer surface proteins A and C in Lyme disease

The outer surface proteins (Osps) of Borrelia burgdorferi, the etiologic agent of Lyme disease, are principle targets of protective immune responses against this organism. Whereas most North American strains of B. burgdorferi in culture express an abundant amount of Osp A, antibodies to this protein are either absent or only weakly detected in the sera of naturally infected patients or experimentally infected mice. In contrast, Osp C, which has variable expression on cultured organisms; elicits an early, strong humoral response. To examine this paradox, we have studied the in vivo adaptation of a cloned population of B. burgdorferi strain N40 during the early course of experimental murine borreliosis. As in human disease, antibodies to Osp A were only weakly present in the early immune repertoire after murine inoculation with low dose (10(3)) spirochetes. In contrast, antibodies to Osp C were prominent, even though on cultured spirochetes Osp C mRNA and protein expression could not be detected by reverse transcription polymerase chain reaction (RT-PCR) or indirect immunofluorescence, respectively. These observations led us to investigate the expression of Osp A and Osp C in vivo. By direct fluorescent staining of uncultured spirochetes ex vivo and by PCR amplification of spirochetal mRNA, we show that Osp C is indeed expressed by some spirochetes after infection in the mouse. Spirochetes expressing Osp A could also be detected within the first 2 wk of infection, but not at 30 d. Osp A mRNA, although present at day 14 of infection, could not be amplified by RT-PCR at day 30, suggesting that the expression of this Osp is transient. This further implies that the late burst in Osp A antibodies in both mice and humans may be anamnestic. These results indicate that either Osp C is upregulated on spirochetes after infection, or Osp C-expressing spirochetes expand preferentially over those expressing Osp A during infection. These results have important implications for vaccine design and offer one explanation for the failure of Osp A antibodies to eradicate spirochetes from the infected host.

An ospA frame shift, identified from DNA in Lyme arthritis synovial fluid, results in an outer surface protein A that does not bind protective antibodies

Passive immunization with murine or human Abs to outer surface protein A (OspA) can protect mice against Borrelia burgdorferi, but OspA Abs elicited during natural infection in mice or humans are unable to clear the spirochete from the infected host. To examine Ab binding by OspA during the course of human infection, we amplified the operon encoding full-length ospA and ospB from synovial fluids of a patient with chronic Lyme arthritis, the first such recoveries from human material, at four separate time points over 4.5 mo, and expressed OspA in Escherichia coli. OspA mAbs that passively protected mice from infection did not bind one of the expressed OspAs, because of a deletion in ospA that resulted in a frame shift and premature stop codon near the carboxyl terminus. However, expressed OspA from a later synovial fluid sample did not contain this deletion. Thus, although altered forms of OspA, which potentially can influence host immune effectiveness, do occur in the human host, they cannot be the only factors responsible for microbial persistence.

An ospA frame shift, identified from DNA in Lyme arthritis synovial fluid, results in an outer surface protein A that does not bind protective antibodies

Passive immunization with murine or human Abs to outer surface protein A (OspA) can protect mice against Borrelia burgdorferi, but OspA Abs elicited during natural infection in mice or humans are unable to clear the spirochete from the infected host. To examine Ab binding by OspA during the course of human infection, we amplified the operon encoding full-length ospA and ospB from synovial fluids of a patient with chronic Lyme arthritis, the first such recoveries from human material, at four separate time points over 4.5 mo, and expressed OspA in Escherichia coli. OspA mAbs that passively protected mice from infection did not bind one of the expressed OspAs, because of a deletion in ospA that resulted in a frame shift and premature stop codon near the carboxyl terminus. However, expressed OspA from a later synovial fluid sample did not contain this deletion. Thus, although altered forms of OspA, which potentially can influence host immune effectiveness, do occur in the human host, they cannot be the only factors responsible for microbial persistence.

Cytoplasts generate oxidants but require added neutrophil granule constituents for fungicidal activity against Candida albicans hyphae

Killing of Candida albicans hyphae requires oxidant generation by neutrophils (PMNL), but it is uncertain whether hyphal killing is mediated by PMNL oxidants alone or requires contributions by granule constituents. This was assessed using U-cytoplasts (U-CYT), anucleate PMNL fragments depleted of cytoplasmic granules but retaining motility and respiratory burst activity. Granule-depleted U-CYT killed Staphylococcus aureus, but hyphae remained viable despite targeted generation of putatively fungicidal oxidants by avidly adherent U-CYT. Hyphal killing occurred by combining U-CYT with sublethal concentrations of purified PMNL granule extracts approximating those present in equivalent numbers of intact PMNL. Contributions of granule constituents were not entirely attributable to purified granule constituents with known antimicrobial activity (lactoferrin, cathepsin G, myeloperoxidase, and human neutrophil peptide defensins 1-3) individually or combined. Thus, oxidant generation by intact PMNL may be necessary but not always sufficient to mediate hyphal killing without complementary nonoxidative mechanisms.

Chronic granulomatous disease and glutathione peroxidase deficiency, revisited

We have restudied two kindreds that formed the basis of the original report of autosomal recessive chronic granulomatous disease (CGD) associated with leukocyte glutathione peroxidase deficiency. Case 1 from the original study and the surviving brother of the originally reported case 2 both have severe CGD, with no detectable respiratory burst activity in purified intact neutrophils. However, their leukocytes exhibit normal glutathione peroxidase enzyme activity and gene expression. Examination of phagocyte nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase components known to be defective in CGD reveals no detectable cytochrome b558 nor any membrane activity in a cell-free NADPH oxidase assay system. Molecular analysis of the genes encoding cytochrome b558 subunits shows, in case 1, a C-->T substitution at nucleotide 688 of the gene encoding the gp91-phox subunit of cytochrome b558, resulting in a termination signal in place of Arginine-226. Levels of gp91-phox mRNA are markedly decreased despite normal levels of gene transcription, indicating a post-transcriptional effect of the nonsense mutation on mRNA processing or stability. The X-linked form of CGD developed in this cytogenetically normal female due to the uniform inactivation of the normal X chromosome in her granulocytes, indicated by the expression in her granulocyte mRNA of only one allele of a glucose-6-phosphate dehydrogenase polymorphisms for which she is heterozygous in genomic DNA. Case 2 (of the present study) has distinct mutations in each allele of the p22-phox gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Fate of Borrelia burgdorferi DNA in tissues of infected mice after antibiotic treatment

Persistence of Borrelia burgdorferi DNA in tissues following antibiotic treatment was evaluated in C3H mice inoculated intradermally with 10(3) B. burgdorferi N40 or sterile medium. Half of the infected mice and all of the uninfected mice were treated with ceftriaxone 15 days after inoculation for 5 days. Ear and urinary bladder samples were collected on days 20, 30, and 60 after inoculation for culture and for extraction of DNA and amplification of specific spirochetal DNA by polymerase chain reaction (PCR). PCR primers were specific for a 280-bp portion of a highly conserved region of the gene encoding outer surface protein (Osp) A of B. burgdorferi and for a 328-bp part of the OspB gene. There was excellent concordance between culture and PCR for ears (35/36 mice) and bladders (33/36). Both tissues became uniformly negative at the earliest interval tested after antibiotic treatment. Thus, the ability to amplify B. burgdorferi DNA quickly disappeared from tissues that had become culture-negative after antibiotic treatment, suggesting that serial study of PCR-positive tissues and fluids may be useful for evaluating the efficacy of antibiotic therapy in human Lyme disease.

Detection of Borrelia burgdorferi DNA in museum specimens of Peromyscus leucopus

To determine whether Borrelia burgdorferi was enzootic within the United States at the beginning of the 20th century, ear skin samples taken from museum specimens of the white-footed mouse (Peromyscus leucopus) were examined for evidence of spirochetal DNA. In total, 280 samples from mice collected between 1870 and 1919 were analyzed by a nested polymerase chain reaction protocol. Of these, 2 specimens from the vicinity of Dennis, Massachusetts, during 1894 were reproducibly positive for B. burgdorferi OspA sequences. The remaining 278, representing both currently endemic and nonendemic sites, were negative for spirochetal DNA. These studies suggest that the agent of Lyme disease was present in a suitable reservoir host in the United States before the turn of the century and provide evidence against a hypothesis of recent introduction of this zoonotic agent to North America.

Fc- and non-Fc-mediated phagocytosis of Borrelia burgdorferi by macrophages

The Fc receptor (FcR) for immunoglobulin has been assigned a major role in the ingestion of Borrelia burgdorferi, the Lyme disease spirochete, by macrophages. Yet macrophages readily take up and kill B. burgdorferi that have not been opsonized. By use of doubly-labeled macrophages infected with spirochetes and analyzed by confocal fluorescence microscopy, simultaneous localization of both FcR and spirochetes (opsonized and unopsonized) was quantified. After infection with unopsonized spirochetes, bacterial surface antigen and the FcR remained distinct, confirming the expectation that unopsonized uptake of B. burgdorferi is largely independent of the FcR. A similar lack of colocalization was seen when opsonized spirochetes were ingested by macrophages whose FcRs were sequestered by an immune complex-coated substrate. Furthermore, comparable efficiency of uptake was observed whether or not the FcR was engaged.

Acrodermatitis chronica atrophicans in the United States: clinical and histopathologic features of six cases

Acrodermatitis chronica atrophicans is a chronic cutaneous disease caused by the Lyme disease spirochete Borrelia burgdorferi. Acrodermatitis chronica atrophicans is endemic in some regions of Europe but is only rarely seen in the United States. This report describes the clinical and histopathologic findings in six cases of acrodermatitis chronica atrophicans seen at the Mayo Clinic between 1912 and 1961. Histologic differences between early and late phases of the disease were observed, and multisystemic symptoms consistent with chronic Lyme disease were documented in a subset of the patients. All five patients from whom biographical data were available were European immigrants. Our data suggest that some of the first patients with Lyme disease in the United States came to the Mayo Clinic earlier in this century.

Tyrosine phosphorylation in activated human neutrophils. Comparison of the effects of different classes of agonists and identification of the signaling pathways involved

The tyrosine phosphorylation responses initiated in human neutrophils by soluble and particulate agonists were characterized. Chemotactic factors, hematopoietic growth factors, and inflammatory microcrystals stimulated in a time- and concentration-dependent manner the tyrosine phosphorylation of distinct patterns of substrates: pp120, pp85, pp70, and pp60 in the case of chemotactic factors; pp155, pp130, pp120, pp85, pp60, and pp40 in the case of granulocyte macrophage-CSF; and pp130, pp120, pp70, and pp60 in the case of monosodium urate (MSU) crystals. Several of the single bands on one-dimensional blots (including pp40, pp70, and pp120) could be resolved into multiple spots on two-dimensional gels. The responses of several other chemotactic factors resembled those of FMLP. Cytokineplasts retained the capacity to respond to FMLP, granulocyte-macrophage-CSF, or MSU crystals with a stimulation of tyrosine phosphorylation, and contained the major substrates detected in intact neutrophils. Several unrelated tyrosine kinase inhibitors (herbimycin A, genistein, and erbstatin) strongly diminished the tyrosine phosphorylation response to chemotactic factors. Pertussis toxin abrogated the tyrosine phosphorylation response to FMLP, whereas protein kinase C (Ro 21-8220, chelerithryn) inhibitors were without effect. Chelation of intracellular calcium attenuated the tyrosine phosphorylation response to FMLP. These results indicate that G proteins play a crucial role in the coupling of chemotactic factor receptors to tyrosine phosphorylation and that this coupling occurs in parallel to that of phospholipase C. These results also underline the complexity of the transduction pathways implicated in the initiation of tyrosine phosphorylation.

Tyrosine phosphorylation in activated human neutrophils. Comparison of the effects of different classes of agonists and identification of the signaling pathways involved

The tyrosine phosphorylation responses initiated in human neutrophils by soluble and particulate agonists were characterized. Chemotactic factors, hematopoietic growth factors, and inflammatory microcrystals stimulated in a time- and concentration-dependent manner the tyrosine phosphorylation of distinct patterns of substrates: pp120, pp85, pp70, and pp60 in the case of chemotactic factors; pp155, pp130, pp120, pp85, pp60, and pp40 in the case of granulocyte macrophage-CSF; and pp130, pp120, pp70, and pp60 in the case of monosodium urate (MSU) crystals. Several of the single bands on one-dimensional blots (including pp40, pp70, and pp120) could be resolved into multiple spots on two-dimensional gels. The responses of several other chemotactic factors resembled those of FMLP. Cytokineplasts retained the capacity to respond to FMLP, granulocyte-macrophage-CSF, or MSU crystals with a stimulation of tyrosine phosphorylation, and contained the major substrates detected in intact neutrophils. Several unrelated tyrosine kinase inhibitors (herbimycin A, genistein, and erbstatin) strongly diminished the tyrosine phosphorylation response to chemotactic factors. Pertussis toxin abrogated the tyrosine phosphorylation response to FMLP, whereas protein kinase C (Ro 21-8220, chelerithryn) inhibitors were without effect. Chelation of intracellular calcium attenuated the tyrosine phosphorylation response to FMLP. These results indicate that G proteins play a crucial role in the coupling of chemotactic factor receptors to tyrosine phosphorylation and that this coupling occurs in parallel to that of phospholipase C. These results also underline the complexity of the transduction pathways implicated in the initiation of tyrosine phosphorylation.

Misoprostol stimulates leukocyte cyclic adenosine 3',5' monophosphate production and synergizes with colchicine: novel combination of established drugs may boost anti-inflammatory potential

Elevation of intracellular cyclic adenosine 3',5' monophosphate (cAMP) inhibits various proinflammatory and immune responses of leukocytes. Among agents known to stimulate cAMP production in these cells, prostaglandins E (PGEs) have received particular attention as potential immunosuppressive and/or anti-inflammatory drugs. Their clinical use, however, is limited by poor oral absorption and extreme metabolic instability. Misoprostol, a synthetic analog of PGE1 that can be given orally and that has a significantly longer biological half-life, is now used to prevent or treat nonsteroidal anti-inflammatory drug (NSAID)-induced gastric injury. Because it might also exert anti-inflammatory effects on leukocytes, we have characterized the effects of misoprostol on cAMP production in these cells. We have found that misoprostol does stimulate cAMP production, although with some-what less potency and maximal effect than PGE1; this stimulation is synergistically increased by pretreatment of cells with colchicine; a clinically relevant dose of colchicine is effective given sufficient pretreatment time, and preexposure of cells to colchicine enables a clinically relevant dose of misoprostol to stimulate cAMP generation. We conclude that colchicine and misoprostol represent a drug combination that might prove clinically useful for therapy of inflammatory disease.

Target imbalance: disparity of Borrelia burgdorferi genetic material in synovial fluid from Lyme arthritis patients

Lyme arthritis is a late manifestation of Lyme disease that results in episodic synovial inflammation and swelling. Although this process is thought to be driven directly by the spirochetal etiologic agent, Borrelia burgdorferi, the organism itself has been recovered by culture only twice. In contrast, polymerase chain reaction (PCR) studies are usually positive. This apparent discrepancy in 19 culture-negative synovial fluid specimens from 18 patients with Lyme arthritis was investigated. In all 19, DNA sequences characteristic of plasmid-encoded genes OspA and OspB were easily detected. However, despite equivalent or even superior analytic sensitivity for detection of cultured organisms, the reactivity of two genomic DNA targets was often weak or absent altogether in the clinical specimens. This apparent overrepresentation of B. burgdorferi plasmid sequences was found exclusively in clinical specimens and not in cultured organisms. The physiologic imbalance of genomic and plasmid DNA reactivity in B. burgdorferi infection may signal an underlying pathogenetic mechanism.

Circulating Borrelia burgdorferi in patients with acute Lyme disease: results of blood cultures and serum DNA analysis

To determine the usefulness of blood culture and polymerase chain reaction (PCR) analysis in detecting circulating Borrelia burgdorferi or its DNA, blood and serum from untreated patients with acute Lyme disease were examined. None of the cultures of blood or serum from the 7 patients tested demonstrated spirochetes. Similarly, all patient serum samples, assayed in two laboratories, were negative for B. burgdorferi DNA using PCR amplification. These results suggest that in patients with acute Lyme disease, spirochetes, spirochete DNA, or both circulate early, only intermittently, or at low levels and that neither culture nor PCR testing of blood or serum, as currently done, appears likely to prove generally useful in the diagnosis of Lyme disease.

Heat shock in human neutrophils: superoxide generation is inhibited by a mechanism distinct from heat-denaturation of NADPH oxidase and is protected by heat shock proteins in thermotolerant cells

Independently of the stimulating agent used, generation of O2- by human neutrophils is transiently inhibited when the cells have been exposed to elevated temperatures. This phenomenon is concomitant with the synthesis of heat shock proteins (HSPs). We have investigated a possible relationship between HSPs and modulation of NADPH oxidase activity in human neutrophils exposed to heat. HSPs were not involved in the inhibition of O2- generation since 1) in enucleated cytoplasts, which are unable to synthesize proteins, the generation of O2- was inhibited after exposure to 43 degrees C, 2) using actinomycin D (Act D) in intact cells, it was possible selectively to inhibit the synthesis of HSPs without modifying the inhibition of NADPH oxidase activity that followed HS. Furthermore, the recovery of NADPH oxidase activity was not under the control of HSPs because the enzyme recovered as well in Act D-treated neutrophils. The NADPH oxidase activity was reconstituted in a cell-free assay by combining the cytosol with the plasma membrane-enriched fraction in the presence of arachidonic acid (AA) and NADPH. Subcellular fractions obtained from control or heated neutrophils exhibited similar oxidase activities suggesting that heat exposure did not induce denaturation of the oxidase components but rather altered the mechanisms of translocation and/or assembly of these components with the plasma membrane. This hypothesis was supported by the inhibition of the granule release in heated cells, a process which also requires translocation and association fusion with the plasma membrane. On the other hand, preexposure of neutrophils to HS prevented the inhibition of O2- generation during a second challenging HS. This acquired thermotolerance was abolished when the synthesis of HSPs was inhibited during the first HS with Act D, indicating a direct relationship between protection of O2- generation and synthesis of HSP. Here we demonstrate that synthesis of HSPs and inhibition or recovery of NADPH oxidase activity are concomitant but unrelated phenomena. In contrast, accumulation of HSPs in thermotolerant neutrophils appeared to play an important role in the prevention of NADPH oxidase inhibition. These results provide further insights into the behavior of human neutrophils and NADPH oxidase upon heat injury.

The fate of Borrelia burgdorferi, the agent for Lyme disease, in mouse macrophages. Destruction, survival, recovery

The macrophage is a known reservoir for a number of infectious agents, and is therefore a likely candidate site for persistence of Borrelia burgdorferi, the Lyme spirochete. We report that unopsonized B. burgdorferi enter macrophages rapidly, resulting mainly in degradation but occasionally in apparent intracellular persistence. We studied uptake of spirochetes by macrophages by simultaneously labeling infected cells with antibodies to B. burgdorferi and with sequential components of the endocytic pathway, and we examined optical sections (0.5-1.0 micron in thickness) of these cells by confocal fluorescence microscopy at multiple time points after infection. We found that only 5 min of incubation at 37 degrees C were required for nearly 100% of B. burgdorferi to enter a lysosomal glycoprotein-positive compartment, whereas 60 min were required for 90% of the spirochetes to appear in a cathepsin L-positive compartment under the same conditions. We also labeled infected living cells with acridine orange to distinguish live from killed intracellular organisms. Although the large majority of spirochetes within a given cell were dead, we saw occasional live ones up to 24 h (the longest interval examined) after all extracellular organisms had been lysed in distilled water. Moreover, we can reculture spirochetes from macrophages after infection. Persistence of spirochetes within macrophages provides a possible pathogenetic mechanism for chronic or recurrent Lyme disease in man.

The fate of Borrelia burgdorferi, the agent for Lyme disease, in mouse macrophages. Destruction, survival, recovery

The macrophage is a known reservoir for a number of infectious agents, and is therefore a likely candidate site for persistence of Borrelia burgdorferi, the Lyme spirochete. We report that unopsonized B. burgdorferi enter macrophages rapidly, resulting mainly in degradation but occasionally in apparent intracellular persistence. We studied uptake of spirochetes by macrophages by simultaneously labeling infected cells with antibodies to B. burgdorferi and with sequential components of the endocytic pathway, and we examined optical sections (0.5-1.0 micron in thickness) of these cells by confocal fluorescence microscopy at multiple time points after infection. We found that only 5 min of incubation at 37 degrees C were required for nearly 100% of B. burgdorferi to enter a lysosomal glycoprotein-positive compartment, whereas 60 min were required for 90% of the spirochetes to appear in a cathepsin L-positive compartment under the same conditions. We also labeled infected living cells with acridine orange to distinguish live from killed intracellular organisms. Although the large majority of spirochetes within a given cell were dead, we saw occasional live ones up to 24 h (the longest interval examined) after all extracellular organisms had been lysed in distilled water. Moreover, we can reculture spirochetes from macrophages after infection. Persistence of spirochetes within macrophages provides a possible pathogenetic mechanism for chronic or recurrent Lyme disease in man.

Cytokineplasts and U-cytoplasts from human polymorphonuclear leukocytes: role of granule-poor motile fragments in the analysis of cell physiology

We have been using granule-poor anucleate fragments--cytokineplasts and U-cytoplasts--released from human peripheral blood polymorphonuclear leukocytes (granulocytes; PMN) to study cell functions that bear on aspects of the inflammatory response. The work is particularly aimed at the relationships among specific but overlapping areas of leukocyte activity: adherence, locomotion, target recognition, chemotaxis, penetration of endothelial monolayers, ingestion, the increased metabolic activity that ordinarily accompanies phagocytosis or other cell activation processes, degranulation of lysosomal structures, and intracellular killing. The ways in which these activities can be separated from one another may distinguish obligate interactions from mere concomitance, and may reveal the specific pathways by which cell function is altered. We have found that cytoplasts provide a unique way of looking at the composition and function of the cell's motile and killing machinery, in greatly simplified systems.

Evidence for reactive nitrogen intermediates in killing of staphylococci by human neutrophil cytoplasts. A new microbicidal pathway for polymorphonuclear leukocytes

In anucleate, granule-poor, motile fragments from human blood neutrophils (cytokineplasts; CKP), the nitric oxide synthase inhibitor N omega-monomethyl-L-arginine (NMMA) produced a modest decrease in uptake of staphylococci from supernatants (P less than 0.02, n = 7), and a marked decrease in the killing of cytoplast-associated bacteria (P less than 0.001, n = 7). After 60 min of incubation with bacteria, NMMA-treated cytoplasts had a mean of over 3.5 times as many live, CKP-associated staphylococci as did controls (51% of the inocula versus 14%), despite having taken up fewer. Effects on both uptake and killing were reversible by L-arginine but not by D-arginine. Results were the same with other granule-poor cytoplasts (U-cytoplasts, U-CYT), which, unlike CKP, retain activatable oxidase activity. Killing by intact PMN, including those from a patient with chronic granulomatous disease, was not inhibited by NMMA. Thus, the ability to discern effects of NMMA correlated with the paucity of granules, without regard to the presence or absence of activatable oxidase. We propose that the generation of reactive nitrogen intermediates serves as an additional microbial killing pathway in PMN, and that cytoplasts can be used to help delineate the spectrum of susceptible targets.

Identification of a thermolabile component of the human neutrophil NADPH oxidase. A model for chronic granulomatous disease caused by deficiency of the p67-phox cytosolic component

Mild heating of human neutrophils inactivates the respiratory burst oxidase, producing a defect in superoxide production and bacterial killing comparable to that seen in patients afflicted with chronic granulomatous disease (CGD). We have now investigated the mechanism and specificity of this inactivation by examining the effect of mild heating on the known oxidase components: the membrane-bound subunits of the cytochrome b558 (gp91-phox and p22-phox) and the two cytosolic oxidase factors (p47-phox and p67-phox). Heating (46 degrees C for 7.5 min) caused intact neutrophils to lose greater than 85% of their capacity to produce superoxide, a defect which was localized to the cytosolic, but not the membrane, fraction. Complementation studies with CGD cytosols deficient in either p47-phox or p67-phox suggested that the defective component of heat-inactivated cytosol was p67-phox. This was confirmed by experiments showing that recombinant p67-phox, but not p47-phox, exhibited lability at 46 degrees C and completely reconstituted oxidase activity of heat-treated cytosol. These studies indicate that mild heating of either intact neutrophils or normal neutrophil cytosol results in a selective inactivation of p67-phox, providing a model oxidase system for the extremely rare p67-phox-deficient form of CGD.

Protein kinase C isoforms in human neutrophil cytoplasts

Granule-poor human neutrophil cytoplasts, prepared without heat or cytochalasin B treatment so as to preserve both motile function and activatable respiratory burst oxidase, were investigated for their content of several isoforms of protein kinase C (PKC). Immunoblotting with isoform-specific rabbit antibodies (Abs) to PKC revealed that both the alpha-specific and the beta(I and II)- specific Abs recognized a protein band of 78 kd comigrating with PKC from rat brain cytosol. The gamma-specific antiserum did not detect any protein of this molecular mass. The cytoplast beta-PKC band was more readily detected than the cytoplast alpha-PKC band. Antibodies to beta I- or beta-II- specific PKC sequences showed the beta II subtype to be the predominant form of beta-PKC, although some beta I was also found. The identity of the 78-kd cytoplast bands as PKC was established by the fact that phorbol ester treatment of intact cytoplasts induced translocation of the bands from cytosol to membrane fractions. However, whereas PKC specific activity was similar in cytoplast lysates and brain cytosol, immunoreactivity of cytoplast alpha- and beta-PKC bands was considerably less than that of rat brain. Hydroxylapatite chromatography of partially purified cytoplast PKC revealed two major peaks of PKC activity precisely coeluting with brain alpha- and beta-PKC and displaying comparable enzymatic activities despite the relatively weak immunoreactivity of cytoplast alpha- and beta-PKC. To our knowledge, this is the first demonstration that human neutrophil-derived cytoplasts contain alpha, beta I, and beta II forms of PKC and that each isoform translocates from cytosol to membrane upon exposure to phorbol ester at concentrations that induce superoxide production. In addition, our evidence raises the possibility that cytoplasts may also possess other isoforms of PKC that we are unable to detect with our alpha, beta, and gamma antibodies. Finally, the granule-poor cytoplasts seem a particularly useful preparation in which to examine the role of individual PKC isoforms in neutrophil activation.

Photopheresis for rheumatoid arthritis

For rheumatoid arthritis, an effective therapy with minimal toxicity would be welcome. In a six-month pilot study of seven patients with a variety of presentations and previous treatments, we tested a therapy involving the extracorporeal photoactivation of biologically inert methoxsalen (8-methoxypsoralen) by ultraviolet A energy to a form that covalently cross-links lymphocyte DNA; the injured cells are returned to the patient. Prior experimental studies had indicated that this regimen produces an immune reaction against antigens on treated T Cells, and a clinical trial in cutaneous T cell lymphoma had been successful. The current patients were treated on two successive days monthly (or, later on, biweekly). Between 12 and 16 weeks of therapy there appeared to be a breakpoint after which joint counts and joint scores of four patients began to improve. In three of them, these measures eventually diminished by mean values of 71% and 80%, respectively, of their baseline values, along with variable improvement in less direct indicators of clinical response. The joints of the fourth patient improved modestly (by 33% and 59%, respectively, of baselines) but he required alternative therapy, and those of the remaining three patients did not improve. Mean slopes for the joint counts were significantly different from zero after the apparent breakpoint (but not before), whether one examined the four apparent responders (p = 0.01) or the entire group of seven (p = 0.01). After completion of therapy, there was also a delay, of two to three months, in the clinical deterioration of those who had improved. There was only one mechanical adverse effect--a single episode of transient hypotension in 102 treatment sessions--and no toxic ones. This preliminary study suggests that extracorporeal photochemotherapy may be effective at least in the short term in certain patients with rheumatoid arthritis, with less apparent toxicity than that of any of the drugs currently used for this disorder. It deserves further evaluation.

Cryopreserved cytoplasts from human neutrophils migrate across monolayers of human endothelial cells in response to a chemoattractant gradient

We have measured the capacity of two types of granule-poor anucleate cytoplasmic fragments (cytoplasts) from human polymorphonuclear leukocytes (PMN) to migrate across the barrier imposed by monolayers of human umbilical vein endothelial cells (EC) with and without chemotactic stimulation by fMLP. Cytoplasts were made by brief heating of PMN attached to surfaces (CKP) or by discontinuous gradient centrifugation (U-CYT). In the absence of chemoattractant, both types of cytoplast adhered poorly to endothelial cell monolayers, as did unstimulated intact PMN from which the cytoplasts were derived. In the presence of a transendothelial chemoattractant gradient both types of cytoplast exhibited a marked increase in adherence to, and migration across, endothelial monolayers; CKP did so to the same extent as chemoattractant-stimulated intact PMN. Since these motile cytoplasts are markedly deficient in most cytoplasmic organelles they may serve as useful tools for the dissection of cellular mechanisms that mediate PMN migration across endothelia.

Cryopreserved cytoplasts from human polymorphonuclear leukocytes (cytokineplasts) are chemotactic at speeds comparable to those of fresh intact cells

Cytokineplasts (CKP) are granule-poor cytoplasts from human polymorphonuclear leukocytes (PMN) that retain motile function, even (unlike the parent PMN) after cryopreservation. Employing time-lapse videomicroscopy, we examined the chemotactic properties of CKP after cryopreservation toward erythrocytes lysed by laser microirradiation. Paths of locomotion were plotted for six CKP in the field, and velocities were calculated at 10-sec intervals. Mean velocities of the six fragments, ranging from 9.3 to 20.8 microns/min, are of the order of fresh, intact PMN, the fastest of locomoting cells.

Treatment of rheumatoid arthritis by extracorporeal photochemotherapy. A pilot study

In a 6-month pilot study of 7 patients with rheumatoid arthritis, we tested a treatment involving the extracorporeal photoactivation of biologically inert methoxsalen (8-methoxypsoralen) by ultraviolet A energy to a form that covalently cross-links lymphocyte DNA; the injured cells are reinfused into the patient. Prior experimental studies had indicated that this regimen produces an immune reaction against antigens on treated T cells, and a clinical trial in patients with cutaneous T cell lymphoma had been successful. The current study patients were treated monthly, on 2 successive days (or biweekly, later on). Between 12 and 16 weeks of therapy, there appeared to be a breakpoint, after which the joint counts and joint scores of 4 of the patients began to improve. In 3 of the 4 patients, these measures eventually diminished by a mean of 71% and 80% of baseline values, respectively, and there was variable improvement in less direct indicators of clinical response. The joint counts and scores of the fourth patient improved modestly (by 33% and 59% of baselines, respectively) but he required alternative therapy, and those of the remaining 3 study patients did not improve. Mean slopes for the joint counts were significantly different from zero after the apparent breakpoint (but not before), whether one examined the 4 apparent responders (P = 0.01) or the entire group of 7 patients (P = 0.01). After completion of therapy, there was also a delay, of 2-3 months, in the clinical deterioration of those patients who had improved. There was only 1 mechanical adverse effect--a single episode of transient hypotension in 102 treatment sessions--and no toxic effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Lyme disease

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