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B J Luft

Publications and source records attributed to B J Luft.

At least 19 recordsLinked to original sources
PubMed1995

Detection of Borrelia burgdorferi-specific antigen in antibody-negative cerebrospinal fluid in neurologic Lyme disease.

OBJECTIVE: To determine the potential of detection in CSF of specific Borrelia burgdorferi antigen, OspA, as a marker of infection in neurologic Lyme disease and compare this with the detection of antibody. DESIGN: CSF from 83 neurologic patients in an area highly endemic for Lyme disease was examined prospectively for (1) OspA by antigen capture ELISA and Western blot employing monoclonal antibodies, and for (2) B burgdorferi antibodies by ELISA. RESULTS: Of the 35 of 83 (42%) patients who were positive for OspA antigen in their CSF, 15 (43%) were antigen positive despite being antibody-negative in CSF. Seven of these 15 (47%) had otherwise normal routine CSF analyses. Six of these 15 (40%) patients met strict CDC surveillance criteria for Lyme disease; four (27%) patients had seroconversion coincident with new neurologic problems; and three (20%) with characteristic syndromes for Lyme disease were seronegative, but had complexed antibody to B burgdorferi. The final two patients (13%) were seropositive and had unexplained neurologic problems not characteristic of Lyme disease. CONCLUSIONS: B burgdorferi antigen can be detected in CSF that is otherwise normal by conventional methodology, and can be present without positive CSF antibody. Since CSF antigen implies intrathecal seeding of the infection, the diagnosis of neurologic infection by B burgdorferi should not be excluded solely on the basis of normal routine CSF or negative CSF antibody analyses.

Adult↗
PubMed1993

Evidence for an alpha-helical epitope on outer surface protein A from the Lyme disease spirochete, Borrelia burgdorferi: an application of steady-state and time-resolved fluorescence quenching techniques.

Outer surface protein A (OspA) is a major antigen of Borrelia burgdorferi, the etiological agent of Lyme disease. A recombinant form of OspA (OspA-257) from B. burgdorferi, strain B31, contains 257 amino acids and a single tryptophan residue at position 216 (Trp-216). Mapping studies indicate that Trp-216 is involved in the epitope for the agglutinating monoclonal antibody 105.5. However, the fluorescence emission maximum of the native protein is 330 nm, indicating that Trp-216 is not solvent-exposed. Primary structure analysis suggests an alpha-helical conformation for residues approx. 204-217, which, if located on the protein surface, would allow Trp-216 to be buried, while leaving hydrophilic residues on the opposite side of the helix exposed. This helix would place Lys-212 within approx. 6 A of Trp-216; the presence of such a positively-charged residue can, in principle, be ascertained from fluorescence quenching studies. Stern-Volmer plots confirm that Trp-216 is indeed buried in the native protein, but is readily accessible to the small polar quencher, acrylamide. Furthermore, the dominant component of the fluorescence emission shows only weak dynamic quenching by the positively-charged quencher, Cs+, while the minor component undergoes static quenching by I-, indicating the proximity of a positively-charged residue. These data are consistent with the existence of an alpha-helix from residues 204-217 in the predicted orientation at the protein surface, hence indicating the structure of the antigenic determinant.

Amino Acid Sequence↗
PubMed1993

Cross-reactive antigenic domains of the flagellin protein of Borrelia burgdorferi.

The p41 flagellin of Borrelia burgdorferi is the most common antigen recognized by serum of patients with Lyme borreliosis. This antigen shares amino acid homology, particularly in the amino and carboxy termini, with periflagellar antigens found in other microorganisms including Treponema pallidum. We cloned and expressed the p41 open reading frame in Escherichia coli and expressed it both as TrpE fusion and full-length unfused proteins. Also, we generated deletion constructs of various portions of the gene. Sera from patients with late Lyme borreliosis and secondary syphilis were used to identify the recombinant proteins by immunoblot analysis. Sera from 26 patients with Lyme borreliosis, 20 with secondary syphilis and 10 controls were used to identify cross-reactive domains of the B. burgdorferi flagellin. The variable region (amino acids 131-234) of the protein was recognized by 59% (15/26) of patients with late Lyme borreliosis compared to 30% (6/20) of patients with secondary syphilis and no (0/10) control patients. It appears that cross-reactive epitopes between B. burgdorferi and T. pallidum extend to the variable region of the flagellin.

Borrelia burgdorferi Group↗
PubMed1992

Analysis and expression of the Borrelia burgdorferi P/Gau fla gene: identification of heterogeneity with the B31 strain.

The flagellin gene from the P/Gau strain of Borrelia burgdorferi was cloned and sequenced. The translated P/Gau flagellin protein differed from the flagellin of the B31 strain at 13 of 336 amino acids. This includes seven differences between amino acids 190-234, an immunodominant and specific region for B. burgdorferi. The entire flagellin molecule, as well as peptides of the internal portion of the protein which is more specific for B. burgdorferi, has been expressed in Escherichia coli using a pET7HIS.2 expression system. These peptides may be of great value for the development of sensitive and specific recombinant-based serological assays.

Amino Acid Sequence↗
PubMed1992

Invasion of the central nervous system by Borrelia burgdorferi in acute disseminated infection.

OBJECTIVE: To determine central nervous system (CNS) involvement in acutely disseminated Borrelia burgdorferi infection by measurement of borrelia-specific DNA using the polymerase chain-reaction (PCR) assay and to compare the results of this with standard serological tests. DESIGN: Prospective study with laboratory investigators blinded to clinical data. SETTING: Multicenter office practice with a central reference laboratory. PATIENTS: Cerebrospinal fluid (CSF) was collected from 12 patients with acute disseminated Lyme borreliosis with less than 2 weeks of active disease. The normal control specimens came from 16 patients whose CSF samples had been sent to the clinical laboratory for tests unrelated to the present study. MAIN OUTCOME MEASURES: Clinical evidence of disease and laboratory abnormalities. RESULTS: Eight of the 12 patients (four of six with multiple areas of erythema migrans and four of six with cranial neuritis without erythema migrans) had B burgdorferi-specific DNA in their CSF. Among the 12 patients studied, nine had acute cranial neuritis and six had multiple erythema migrans lesions. Just four of the eight who were found to have spirochetal DNA in their CSF had complaints suggestive of CNS infection. In three of the PCR-positive CSF samples, no other abnormalities were noted. None of 16 samples from controls were positive in the PCR assay. CONCLUSION: B burgdorferi can invade the CNS early in the course of infection. Careful consideration should be given to choosing antibiotics that achieve adequate CSF levels in patients with disseminated infection.

Antibodies, Bacterial↗
PubMed1992

Toxoplasmic encephalitis in AIDS.

Involvement of the central nervous system (CNS) is common in patients with advanced disease due to human immunodeficiency virus (HIV). Symptoms range from lethargy and apathy to coma, incoordination and ataxia to hemiparesis, loss of memory to severe dementia, and focal to major motor seizures. Involvement may be closely associated with HIV infection per se, as in the AIDS dementia complex, but is frequently caused by opportunistic pathogens such as Toxoplasma gondii and Cryptococcus neoformans or malignancies such as primary lymphoma of the CNS. The clinical presentations of attendant and direct CNS involvement are remarkably non-specific and overlapping, yet a correct diagnosis is critical to successful intervention. Toxoplasmic encephalitis is one of the most common and most treatable causes of AIDS-associated pathology of the CNS. A great deal has been learned in the last 10 years about its unique presentation in the HIV-infected patient with advanced disease. Drs. Benjamin J. Luft of the State University of New York at Stony Brook and Jack S. Remington of the Stanford University School of Medicine and Palo Alto Medical Foundation's Research Institute have studied T. gondii for many years and are two of the leading experts in the field. This commentary comprises an update of their initial review (J Infect Dis 1988;157:1-6) and a presentation of the current approaches to diagnosing and managing toxoplasmic encephalitis in HIV-infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The 93-kilodalton protein of Borrelia burgdorferi: an immunodominant protoplasmic cylinder antigen.

Using immunoblots, we identified proteins of Borrelia burgdorferi recognized by sera from 62 patients with either acute or chronic Lyme disease. In all groups studied, the 41-kDa flagellar protein and a relatively minor 93-kDa protein (p93) were the most commonly recognized antigens in patients with acute and chronic disease due to B. burgdorferi. A murine monoclonal antibody (MAb 181.1) was developed against p93, and the antigen was detected by immunoblot analysis in four European and American strains of B. burgdorferi. On two-dimensional gel electrophoresis, p93 had an apparent pI of 6.8. Immunoelectronmicroscopy with MAb 181.1 demonstrated that p93 is located within the protoplasmic cylinder compartment of the organism. The gene encoding p93 was retrieved from a phage expression library. The derived amino acid sequence of p93 confirmed chemical characterization of the antigen, including its amino-terminal peptide sequence. The derived amino acid sequence predicted it to be predominantly alpha helical. A prominent antigenic domain located at the carboxy portion of the protein was recognized by human and rabbit polyclonal antisera and human (MAb D4) and mouse (MAb 181.1) MAbs.

Amino Acid Sequence↗
PubMed1992

Characterization of a Borrelia burgdorferi dnaJ homolog.

The gene encoding a Borrelia burgdorferi DnaJ homolog, located immediately 3' of the hsp70 gene, was characterized. Although there is a single copy of the dnaJ gene on the spirochetal chromosome, two distinct dnaJ transcripts are detected in B. burgdorferi RNA. RNA blot analysis indicates that the dnaJ gene can be transcribed alone or as part of a larger transcript containing the hsp70 homolog.

Amino Acid Sequence↗
PubMed1992

Borrelia burgdorferi HSP70 homolog: characterization of an immunoreactive stress protein.

The gene encoding an immunoreactive Borrelia burgdorferi HSP70 homolog was isolated and characterized. The predicted amino acid sequence of this spirochetal protein confirms that this gene encodes a member of the HSP70 family of proteins. Although there appears to be a single copy of this gene on the spirochetal chromosome, two distinct transcripts hybridizing to the hsp70 probe are detected in RNA isolated from B. burgdorferi. The amount of spirochetal HSP70 RNA transcripts is shown to be thermally regulated. Antibodies in the serum of three Lyme arthritis patients and cloned T-cell lines isolated from one patient with Lyme arthritis recognize the expressed recombinant HSP70, indicating that it is an immunologically important spirochetal antigen. Antibodies in a rabbit antiserum, as well as antibodies in the serum of two of three Lyme arthritis patients examined, bound to expressed truncated recombinant HSP70s with 250 amino acids deleted from either the amino or carboxy terminus of the protein. However, antibodies in the serum of three Lyme arthritis patients, which were reactive with spirochetal HSP70, did not cross-react with human HSP70 proteins.

Adolescent↗
PubMed1992

Mapping the major antigenic domains of the native flagellar antigen of Borrelia burgdorferi.

Purified flagellar protein (p41) of Borrelia burgdorferi (strain B31) was subjected to chemical cleavage with hydroxylamine or proteolysis with V8 protease, endoproteinase Asp-N, or alpha-chymotrypsin. The resulting polypeptides were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their positions in the published DNA sequence of the p41 protein were determined by amino-terminal sequencing and amino acid analysis. Epitope specificities of antibody binding by a monoclonal antibody raised by immunization of mice with purified flagella and pooled sera from patients with multiple erythema migrans, late Lyme borreliosis, or secondary syphilis were analyzed by Western blots (immunoblots) of peptides transferred to Immobilon polyvinylidene difluoride filters. The major epitope binding one murine monoclonal antibody (158) was localized to a carboxy-terminal domain that includes residues 300 to 336. The dominant epitopes binding human polyclonal antibodies are in the central portion of the molecule (residues 182 to 218) that is not conserved compared with other bacterial flagellins. Additional reactive epitopes were identified in the amino-terminal domain of the protein. Sera from patients with syphilis bound strongly to the amino-terminal conserved domain, providing a structural basis for cross-reactivity seen in standard enzyme-linked immunosorbent assays, but not to the central part of the molecule. Specific and cross-reactive antigenic determinants need to be considered in the design of improved immunodiagnostics for spirochetal diseases.

Amino Acid Sequence↗
PubMed1992

Pyrimethamine concentrations in serum during treatment of acute murine experimental toxoplasmosis.

Central nervous system toxoplasmosis is a major opportunistic infection in patients with acquired immunodeficiency syndrome. The standard therapy for this infection is pyrimethamine (PYR) and sulfonamides. To assess in vivo if PYR alone could adequately treat toxoplasmosis, a murine model of acute toxoplasmosis was used. The CD1 strain of mice was infected intraperitoneally with 10(4) parasites of the RH strain of Toxoplasma gondii. Pyrimethamine was administered in mouse chow at concentrations of 0, 0.03125, 0.0625, 0.125, 0.25, or 1.0 mg of PYR/g of food, which provides the following daily PYR dosages: 0, 6.25, 12.5, 25, 50, and 200 mg/kg/day. No sulfonamides were administered. Serum PYR levels proved more accurate than mg of PYR/g of food in predicting survival. Mice with serum PYR levels greater than or equal to 500 ng/ml (2 microM) survived and had no parasites present on peritoneal lavage. Mice with serum PYR levels less than 100 ng/ml (0.4 microM) had a 100% mortality rate and the average parasite count was 3 x 10(7) organisms in the lavage fluid. At a PYR level of 370 ng/ml, six of 11 mice survived and the lavage fluid contained 2.5 x 10(5) organisms. Previously, using 3H-uracil in an in vitro assay, PYR at a concentration of 500 ng/ml was shown to be as effective in inhibiting Toxoplasma growth as the combination of PYR (100 ng/ml) and sulfonamides 25 micrograms/ml). These data suggest the potential usefulness of PYR for monotherapy of toxoplasmosis and are consistent with previously described in vitro assays.

Acute Disease↗
PubMed1991

Characterization of an immunoreactive 93-kDa core protein of Borrelia burgdorferi with a human IgG monoclonal antibody.

Lyme borreliosis is an infectious disease caused by the tick-borne spirochete Borrelia burgdorferi, which carries the potential for chronic infection. Ag on the etiologic Borrelia are currently being defined structurally and their ability to elicit immune responses delineated. EBV can be used to immortalize human B. burgdorferi-specific B cells from infected donors and generate antibodies against antigenic epitopes encountered in natural infection. A human mAb secreting EBV-transformed B cell line, D7, has been developed that is specific for a 93-kDa B. burgdorferi protein and has been used to characterize this potentially important Ag. D7 produces an IgG3 antibody that detects the 93-kDa Ag as well as smaller fragments at 46 kDa and lower molecular mass. The antibody detects similar epitopes on all B. burgdorferi isolates tested and on a Borrelia hermsii protein with molecular mass greater than 100 kDa but binds poorly to Treponema species. In contrast, polyclonal sera from Lyme disease patients show little binding to the homologous Ag in B. hermsii. Structurally, the 93-kDa protein is associated with the flagellum and may be firmly anchored in the protoplasmic cylinder. It is not solubilized by nonionic detergent treatment of the whole Borrelia. Antibodies against a comparable m.w. protein are present in sera from patients with both early and late infection. Thus, antibodies against this Ag are a sensitive and specific marker of Borrelia infection. This Ag is likely of structural importance and may represent a target of host defenses.

Antibodies, Bacterial↗
PubMed1991

Immunologic and structural characterization of the dominant 66- to 73-kDa antigens of Borrelia burgdorferi.

The 66- to 73-kDa proteins of Borrelia burgdorferi are dominant immunogens and expressed in all strains of B. burgdorferi. The humoral response to these Ag occurs relatively early during the course of infection. Two-dimensional Western blot analysis of this group of Ag revealed them to consist of a tetrad of proteins with apparent molecular mass of 66, 68, 71, and 73 kDa. Furthermore, in this study we demonstrate the 66-kDa protein to be a potent inducer of lymphoproliferation in the patient immune to B. burgdorferi. Monospecific polyclonal antibodies and mAb demonstrate that each of these proteins was immunologically distinct. However, direct amino acid sequence of the 66- and 68-kDa Ag was almost identical and had a high level of sequence similarity to the GroEL heat-shock protein (Hsp60) of Escherichia coli and the 60-kDa immunodominant protein of Treponema pallidum. The amino terminal sequence of the 71- and 73-kDa proteins of B. burgdorferi was almost identical and these proteins had remarkable sequence similarity to the DnaK heat-shock protein of E. coli (Hsp70). It appears likely, therefore, that proteins related to the heat-shock family are potent immunogens of B. burgdorferi.

Amino Acid Sequence↗
PubMed1991

An overview of the problem of toxoplasmosis and pneumocystosis in AIDS in the USA: implication for future therapeutic trials.

By the end of 1989, 18,518 cases of Pneumocystis carinii infection and 5,614 cases of Toxoplasma gondii infection were reported to the Centers for Disease Control as the AIDS indicator disease. Pneumocystosis did not vary according to gender, race or risk factors; whereas toxoplasmosis was more common in black males with no known risk factors. Immigrants to the USA from Africa, Latin America and Haiti are three to four times more likely to develop toxoplasmic encephalitis than American-born patients with AIDS. The implications of this epidemiologic data for the predictive value of serology and clinical trials are discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Treatment of acute toxoplasmosis with intravenous clindamycin. The California Collaborative Treatment Group.

The interim results are presented of an ongoing large-scale, prospective, randomized study to determine the potential role of clindamycin in the treatment of toxoplasmic encephalitis. Patients were seropositive for Toxoplasma gondii antibodies and had clinical signs compatible with toxoplasmic encephalitis. Data was available on 33 patients, 15 of whom received pyrimethamine p.o./clindamycin i.v. and then p.o., and 18 of whom received pyrimethamine p.o./sulfadiazine p.o. The interim evaluation did not reveal a remarkable difference between the two regimens in the clinical or radiologic response. Adverse reactions to both regimens were common and frequently multiple, there being more adverse gastrointestinal reactions in patients on pyrimethamine/clindamycin and more adverse hematological reactions in those on pyrimethamine/sulfadiazine.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Mapping antibody-binding domains of the major outer surface membrane protein (OspA) of Borrelia burgdorferi.

The major outer surface membrane protein of Borrelia burgdorferi, OspA, is one of several antigens recognized by sera from some patients in the chronic phase of Lyme borreliosis. We have expressed the OspA open reading frame in Escherichia coli and generated a series of deletion constructs of the gene and expressed them as trpE fusion proteins in E. coli. These constructs were used to identify antibody-binding sites of both rabbit antiserum and mouse monoclonal antibodies (MAbs) directed against OspA. All antibodies tested failed to bind to a fusion protein containing the first 61 amino acids of OspA, suggesting that the amino-terminal domain of OspA is unexposed to the cell surface. The binding site for one MAb, 184.1, was identified in a region centered around amino acid 61, while the binding site for MAb 105.5 was identified in a region centered around amino acids 214 to 217. Sera from two patients which were reactive to OspA identified distinct epitopes that lie between those recognized by our MAbs.

Animals↗