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J Ivanyi

Publications and source records attributed to J Ivanyi.

At least 109 records · Page 6Linked to original sources
PubMed1990

Potential value of serology for diagnosis of extrapulmonary tuberculosis.

The possible benefits for improved diagnosis of extrapulmonary tuberculosis were evaluated by means of a modified serological competition assay. Antibodies to the 38 kD Mycobacterium tuberculosis antigen were detected in 73% of cases of extrapulmonary tuberculosis and 70% of smear-negative cases of pulmonary tuberculosis at a chosen specificity of 98%. Of 55 patients (45%) whose diagnosis of tuberculosis was not made until 7 days or longer after admission, 76% were positive for the antibody. In this group the serological test would have allowed chemotherapy to be started on average 12.5 days earlier and would have obviated the need for 80% of diagnostic biopsies.

Antibodies, Bacterial↗
PubMed1990

Elevated antibody levels to mycobacterial 65-kDa stress protein in patients with superficial candidiasis.

Antibody levels to the mycobacterial 65-kDa stress protein (mSP65) were determined by ELISA in sera from patients with chronic atrophic oral candidiasis, vulvovaginal candidiasis, Candida albicans-infected or noninfected oral lichen planus, or recurrent aphthous ulceration and from subjects with clinically healthy oral mucosa. The results showed significantly elevated anti-mSP65 antibody levels in patients with oral or vulvovaginal candidiasis and in patients with Candida-infected lesions of lichen planus when compared with patients with noninfected lichen planus or recurrent oral ulceration and with matched healthy controls (P less than .001). Immunoblot analysis showed that the rabbit antiserum that strongly bound to mSP65 cross-reacted only weakly with a homologous band of a soluble C. albicans extract. Moreover, the binding of antibodies from patients with candidiasis to the mSP65 antigen was not inhibited in the presence of Candida extract. In view of the poor serologic cross-reactivity, it seems plausible that the recall stimulation of anti-mSP65-producing B cells could be induced by helper T cells that cross-react with the structurally homologous protein of C. albicans.

Adult↗
PubMed1990

Presence of human 65 kD heat shock protein (hsp) in inflamed joints and subcutaneous nodules of RA patients.

Monoclonal antibodies to the human homologue of the bacterial 65 kD heat shock protein (hsp) were used to investigate the tissue distribution of endogenous hsp 65 in normal versus rheumatoid synovial tissue, in subcutaneous nodules of patients with rheumatoid arthritis (RA) and in several instances of non-rheumatoid inflammation. A strong reactivity of the anti-hsp antibody was found in the cartilage-pannus junction in rheumatoid joints and in rheumatoid nodules, but not in normal joints or in normal or inflamed kidney or liver (irreversible graft rejection, chronic glomerulonephritis or primary biliary cirrhosis). The findings provide a new hypothetical explanation for a role of T cells reactive with the 65 kD hsp in the generation of both articular and extra-articular lesions in chronic rheumatoid arthritis.

Antibodies, Monoclonal↗
PubMed1990

Distribution in tissue sections of the human groEL stress-protein homologue.

A monoclonal antibody (ML30) raised against the 65 kDa heat-shock protein of mycobacteria showed widespread staining of sections from standard paraffin-embedded human tissues. The staining had a granular pattern and was particularly marked in cells with abundant mitochondria. Increased staining was observed in the synovial lining, histocytes and in the endothelium of reactive and rheumatoid synovium; it was also increased in the reactive lung alveolar lining. It is suggested that the antibody identifies an epitope in mitochondria of a protein homologous with the groEL heat-shock protein of bacteria.

Antibodies, Monoclonal↗
PubMed1990

Genetic influences on the immune repertoire following tuberculous infection in mice.

Differences in the antibody repertoire between B10 and BALB background strains have been found following intraperitoneal infection of mice with Mycobacterium tuberculosis. Western blot analysis showed that B10 sera reacted with only a few antigenic bands, whereas BALB sera reacted with multiple bands, irrespective of the H-2 (b or k) haplotype. The oligo-banded pattern was a feature of live infection, since immunization with the mycobacterial extract in incomplete Freunds' adjuvant (IFA) produced a multi-banded response in both intact and in previously infected B10 mice. The multibanded BALB phenotype was dominantly expressed in (BALB x B10) F1 hybrids. The extent to which antibody levels to individual antigens varied was influenced by the combined effects of background (non-H-2) and H-2 genes: anti-65,000 molecular weight (MW) and anti-71,000 MW IgG levels were high in BALB but absent or low in B10 mice, irrespective of H-2 haplotypes, anti-19,000 MW levels in B10 mice were strongly H-2 controlled, whilst anti-38,000 MW levels were high in all tested strains. Immunoglobulin G1 (IgG1) subclass antibody and splenic interleukin-4 (IL-4) mRNA levels were distinctly lower in B10 than in BALB mice, but in vitro T-cell proliferative responses to mycobacterial antigens did not differ between the tested strains. It is proposed that the limited extracellular release of mycobacterial antigens required to stimulate B cells and/or differential activation of T-cell subsets may explain the narrow antibody repertoire in B10 strains of mice. This may have relevance to the outcome of infection, as bacterial counts were higher in the BALB strains at 10 weeks post-infection.

Animals↗
PubMed1989

Molecular study of the T cell repertoire in family contacts and patients with leprosy.

The specificity of lymphocyte proliferative responses of 22 family contacts and 7 patients with leprosy were analyzed using Ag fractions from soluble extracts of Mycobacterium leprae and Mycobacterium tuberculosis. Fractions 10-100 kDa m.w. from each extract were separated by SDS-polyacrylamide gel electrophoresis, electroblotted to nitrocellulose membrane and solubilized for use in lymphocyte culture. The main immunogenic fractions for both contacts and patients had m.w. of 12,000 to 22,000, 35,000 to 40,000, and 65,000. Determinants which were either distinct or shared by the two extracts were active in each of the immunogenic fractions. Lymphocyte proliferation following stimulation with separated Ag was found also in five subjects who failed to respond to the whole soluble extracts. Stimulatory synthetic peptides were identified for the 65 kDa protein Ag. This technique has permitted the screening of the T cell immune repertoire for the identification of the immunodominant Ag which merit further purification and molecular characterization.

Adult↗
PubMed1989

Differential pattern of T cell recognition of the 65-kDa mycobacterial antigen following immunization with the whole protein or peptides.

The 65-kDa stress protein from Mycobacterium bovis (Bacillus Calmette Guérin) elicited T cell proliferation and antibody responses in seven B10 congenic mouse strains with different H-2 haplotypes. To analyze T cell determinants on this antigen, seven peptides corresponding to six predicted T cell epitopes, and one defined B cell epitope were synthesized. Mice were either immunized with the whole antigen and the specificity of the response was ascertained in respect of the six peptides, or mice were immunized with seven of the peptides and tested for proliferative responses to the whole molecule. The results showed that three peptides carried epitopes to which mice responded following injection of the whole molecule and that immunization with two additional peptides could prime for in vitro stimulation with the native antigen. The latter result indicates the feasibility of generating T cell responses to "cryptic" epitopes on proteins by immunizing with peptides. The peptide-specific T cell responses were distinctly influenced by the H-2 haplotype of mouse strains. However, two peptides were recognized by several H-2-disparate mouse strains, and one peptide could be presented by both I-A and I-E molecules. Immunization with several peptides induced a cross-reactive T cell proliferative response to the homologous GroEL protein isolated from E. coli. The amount of cross-reactivity was influenced by the extent of sequence homology between mycobacterial and E. coli proteins and the major histocompatibility complex class II molecule used to present the peptide.

Amino Acid Sequence↗
PubMed1989

Association of tuberculosis and M. tuberculosis-specific antibody levels with HLA.

In the search for HLA-linked immune response genes that control susceptibility to tuberculosis, we performed HLA typing and measured antibody titers to well-defined Mycobacterium tuberculosis antigenic determinants in 101 patients with sputum smear-positive pulmonary tuberculosis and 64 healthy controls from Surabaya, Indonesia. HLA-DR2 and DQw1 were associated with sputum smear-positive pulmonary tuberculosis (attributable risk = 36% and 39%, respectively), while DQw3 was associated even more strongly with the control group (preventive fraction = 57%). Antibody titers to the TB71 and TB72 epitopes of the 38-kDa protein, present only on tubercle bacilli, were strongly associated with DR2 (Pcorr = .001 and .024, respectively). The association of both the disease and the antibody response to the 38-kDa antigen of M. tuberculosis with Class II HLA genes HLA-DR2 indicates that Ir-gene-mediated regulation of the immune response to this antigen may be of pathogenic significance for the development of sputum smear-positive tuberculosis.

Antibodies, Bacterial↗
PubMed1989

Mechanisms of recrudescence of Mycobacterium bovis BCG infection in mice.

The capacity of various immunosuppressive agents to cause a recrudescence of the replication of Mycobacterium bovis BCG in the spleens of chronically infected mice was investigated. The actions of three corticosteroid preparations, cyclosporin A, and anti-T-cell subset monoclonal antibodies were compared. Treatment of mice with hydrocortisone acetate, which depressed the number of splenic lymphocytes and suppressed T-cell responses, most effectively exacerbated the stationary BCG counts, at 4 to 6 months after infection. The magnitude of reactivation was more pronounced in innately resistant CBA/Ca mice than in the susceptible C57BL/6 strain of mice. Splenic bacterial counts were also amplified by anti-L3T4 antibody when the antibody was injected at the chronic phase, whereas cyclosporin A had an effect only during the initial 6 weeks after BCG infection. Cultures of spleen cells from chronically infected mice showed a significant increase in the numbers of viable BCG recovered after 7 days of incubation in the presence of dexamethasone but not with cyclosporin A. The observed differences between the tested immunosuppressive agents indicate that the stationary bacterial counts during chronic BCG infection are maintained by discrete T-cell actions on the infected macrophages.

Animals↗
PubMed1989

Levels of antibody to defined antigens of Mycobacterium tuberculosis in tuberculous meningitis.

The aim of the study was to develop an antibody immunoassay for tuberculous meningitis with a sensitivity greater than that of the initial bacterial smear while maintaining a 100% specificity. Antibody titers to five purified antigens of Mycobacterium tuberculosis were measured in cerebrospinal fluid by using an enzyme-linked immunosorbent assay technique. Seventy-four patients with tuberculous meningitis (26 culture positive) were compared with 26 patients with purulent meningitis, 69 patients with suspected but excluded tuberculous meningitis, and 29 patients with other neurological diseases. Antibody responses to both the 14-kilodalton (kDa) antigen and lipoarabinomannan were immunodominant, accounting for 74% of those with any antibody titer to a soluble extract of M. tuberculosis. A sensitivity of 61% was achieved (77% for the culture-positive samples) by using immunoglobulin G titers to lipoarabinomannan and the 14-, 19-, and 38-kDa antigens. Thus, estimation of levels of antibody in cerebrospinal fluid to selected mycobacterial antigens would be valuable in the diagnosis of tuberculous meningitis. The possible reasons for the immunodominance of the 14-kDa antigen and lipoarabinomannan in the pathogenesis of tuberculous meningitis are discussed.

Antibodies, Bacterial↗
PubMed1989

The phenotypic and molecular characterization of Nb2 lymphoma cells activated with IL-2 and human growth hormone.

The Nb2 rat lymphoma cell line has the unique property that its growth is dependent on lactogenic pituitary hormones. Cell surface staining with monoclonal antibodies showed expression of class I MHC alloantigens of the RT1u haplotype, but no expression of class II MHC antigens. Staining for differentiation markers was strongly positive with antibodies OX52, W3/13 and OX44. Partial and weaker staining was obtained with CD2, P4/16 and the transferrin receptor. Nb2 cells were negative with CD5, OX40 and CD4, whilst CD8 stained only a minor fraction (1%) and certain variant clones of the cell line. This general pattern of staining is consistent with the phenotype of a small subpopulation of immature T cells. Nb2 cells proliferated in response to recombinant human IL-2, although they did not stain with antibodies against the IL-2 receptor. Enhancement of the stimulation by IL-2 in the presence of a submitogenic concentration of hGH indicated a synergism between these two hormones, and responses were suppressed by a similar dose of cyclosporin A (ID50=2 microg/ml). Although IL-2 could not be identified in culture supernatants, the presence of mRNA for IL-2, IL-2R and IL-4 was demonstrated by dot blot analysis. Finally, evidence that the Nb2 lymphoma is of T-cell lineage was given by Northern blot detection of mRNA for the alpha and beta chains of the T-cell receptor.

Animals↗
PubMed1988

Specificity of proliferative response of human CD8 clones to mycobacterial antigens.

Human CD8 T lymphocyte clones (TLC) were generated from the pleural effusion of patients with tuberculosis using a protocol that required, in addition to antigen, coculture of purified CD8+ T cells, accessory cells, interleukin 2 (IL2) and anti-CD3-Sepharose. The TLC obtained were stimulated by mycobacterial soluble extracts in an IL2-dependent and MHC class I-restricted manner. When antigen-responsive TLC were screened with extracts from the recombinant mycobacterial library they were found to respond to either the Y3125 (100-kDa) or the Y3111 (71-kDa) lambda gt11 clones. Polyacrylamide gel immunoblot analysis demonstrated that the CD8 TLC responded to fractions with the molecular mass range 27-45 kDa in the Y3125 lysogen and 60-90 kDa in the mycobacterial soluble extract. The specificity of TLC reactive with the Y3111 clone was confirmed using the 71-kDa antigen purified from the same lysogen. These TLC recognized sequences common to the 71-kDa protein derived from mycobacteria, E. coli or a human cell line. Studies of three TLC using antigen-presenting cells of known genetic haplotype indicated that stimulation with both the Y3125 and the 71-kDa antigens were restricted by determinants encoded by HLA-B8.

Antigens, Bacterial↗
PubMed1988

Orientation of epitopes influences the immunogenicity of synthetic peptide dimers.

The immunogenicity of synthetic peptide dimers based on epitope sequences derived from the mycobacterial 65-kDa antigen and the foot and mouth disease virus (FMDV) VP1 protein was examined in inbred mice. The analysis was directed towards the potential helper role of a T cell stimulatory mycobacterial epitope (65-85) with respect to poorly immunogenic sites either from the same molecule (422-436) or from VP1 (141-160). The 65-85 repeat homodimer induced an antibody response in CBA/ca but not in C57BL/6 mice, both nonresponders to the 65-85 monomer, and amplified the antibody response in BALB/c, monomer-responder mice. Analysis of the immunogenicity of hybrid dimers in BALB/c mice showed that the orientation of peptides within the dimer is critical for the extent of the produced antibody response. Only the 422-436/65-85 but not the 65-85/422-436 induced antibodies binding to the 422-436 sequence which was nonimmunogenic when injected either as a monomer or dimer. Despite the striking difference in immunogenicity, both tested hybrid dimers reacted equally in the solid-phase immunoassay with antisera raised to 65-85-dimer or 422-436/65-85 peptides or with a monoclonal antibody to the 422-436 epitope. The described differences in antibody responsiveness also cannot be attributed merely to the extent of T cell stimulation since the proliferative responses were uniformly expressed for all relevant combinations of peptides. Antisera to 65-85 dimer and 422-436/65-85 hybrid also reacted with the native 65-kDa protein. Furthermore, the production of FMDV-neutralizing antibodies in response to the 141-160 (VP1-derived)/65-85 hybrid peptide in 141-160 nonresponder B10.D2 mice also confirmed the helper activity of the 65-85 epitope. Thus, combining heterologous peptides with the N-terminal of the mycobacterial 65-85 sequence may be generally applicable for the potentiation of peptide vaccines.

Animals↗
PubMed1988

Stress proteins and the immune response to mycobacteria--antigens as virulence factors?

The immune response to mycobacterial infection includes pathogenic as well as protective activities. It is possible that different types of immune responses are associated with recognition of different antigenic determinants. Amongst the antigens which are prominent in antibody and T cell recognition of mycobacteria, we have identified members of highly conserved stress protein families. Mapping of antigenic determinants on stress proteins shows that both species-specific and conserved regions of these proteins can take part in immune recognition. Induction of an immune response to conserved, "self-like", determinants on stress proteins could play a role in the immunopathology associated with chronic mycobacterial infections.

Amino Acid Sequence↗
PubMed1988

Humoral response to defined epitopes of tubercle bacilli in adult pulmonary and child tuberculosis.

In order to investigate the humoral response to tuberculosis in different categories of patients, serum antibody levels to six epitopes of Mycobacterium tuberculosis in adult pulmonary and child tuberculosis were determined. Serum antibody titres were determined by competitive inhibition with radio-labelled murine monoclonal antibodies in 67 adults and 85 children with tuberculosis and in 79 age-matched controls. BCG vaccination (n = 39) and self-healed tuberculosis (n = 11) in adults gave rise to higher antibody titres to TB68, TB23 and TB72 epitopes (all p less than 0.003) when compared to non-vaccinated controls (n = 18). TB68 titres were higher (p = 0.006) in self-healed than in vaccinated adults. Adult sputum-negative patients (n = 15) had higher titres to TB71 (p = 0.015) and ML34 (p = 0.02) epitopes compared to BCG-vaccinated healthy controls, while sputum-positive patients (n = 41) had higher titres to all epitopes tested (all p less than 10(-4]. The diagnostic sensitivity, with a 95% specificity, was best with the combination of probes TB23, TB68, TB72 for sputum-positive (85%) and TB78, ML34 (53%) for sputum-negative patients. Antibody titres in children with tuberculosis were lower than in adult patients; diagnostic sensitivity in histologically or microbiologically proven cases (n = 18) was only 44%, while that in mediastinal lymph-adenitis (n = 67) was 13.5%. This study suggests that the magnitude and specificity of the humoral response to tubercle bacilli varies with site and severity of infection; the implications for pathogenesis or protective immunity are discussed.

Adolescent↗
PubMed1988

The role of host factors for the chemotherapy of BCG infection in inbred strains of mice.

Host factors have previously been considered to play a role in the efficacy of "incomplete" antituberculous chemotherapy. We investigated this aspect using a model of intravenous infection with M. bovis-BCG in three inbred strains of mice. Viable splenic counts of bacilli (CFU) were monitored following a three week regimen of rifampicin (R) and isoniazid (H) given either immediately or from three weeks after infection. At the end of the immediate (0-3 weeks) therapy the spleens of all mice were sterile and only a minority of animals had demonstrable CFU's at 23 weeks after infection. However, following the delayed-onset (3-6 weeks) therapy we found a pronounced relapse of BCG growth which was about 10 times higher in CBA/Ca and BALB/C than in C57B1/6 mice. These results indicated that host immunity which developed during the first three weeks after infection may have aggravated the relapse of bacterial growth following chemotherapy. This interpretation was corroborated by the finding that the immunosuppressive drug cyclosporin given concurrently with R/H reduced the splenic viable counts of BCG.

Animals↗