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Biomedical subjects

T Lehner

Publications and source records attributed to T Lehner.

At least 199 records · Page 11Linked to original sources
PubMed1982

Detection of RNA complementary to herpes-simplex virus in mononuclear cells from patients with Behçet's syndrome and recurrent oral ulcers.

Viral DNA probes were used in in-situ hybridisation to detect the complementary RNA in mononuclear cells from the blood of normal subjects and patients with Behçet's syndrome and recurrent oral ulcers. Hybridisation of 125I-labelled DNA probes was detected by means of autoradiography and quantitated with a video image-analysis technique. Hybridisation between herpes-simplex virus type 1 (HSV-1) DNA and the complementary RNA in mononuclear cells was significantly greater in 10 of 20 patients with Behçet's syndrome than in controls. Consistently, mononuclear cells from fewer patients showed significant hybridisation with the HSV-2 probe, and the grain counts were also lower. Control DNA probes from adenovirus 2, bacteriophage lambda, and Micrococcus lysodeikticus did not show significant hybridisation. Further separation of the patients into the four types of Behçet's syndrome revealed that mononuclear cells in 8 of 10 patients with the ocular or arthritic types showed significant hybridisation of RNA to the HSV-1 DNA probe, compared with 2 of 10 patients with the mucocutaneous or neurological types. Mononuclear cells from 4 of 8 patients with minor but not major aphthous ulcers also showed significant RNA hybridisation to HSV-1 DNA. The results suggest that at least part of the HSV genome is present and transcribed in peripheral-blood mononuclear cells--probably lymphocytes--of patients with the ocular and arthritic types of Behçet's syndrome and minor aphthous ulcers. The immunopathogenesis of these diseases might therefore be associated with HSV-1.

Behcet Syndrome↗
PubMed1982

Immunisation of rhesus monkeys with Streptococcus mutans, Lactobacillus acidophilus and lipoteichoic acid for protection against dental caries.

An attempt was made to protect rhesus monkeys from dental caries by immunisation with Streptococcus mutans, Lactobacillus acidophilus and lipoteichoic acid (LTA). The vaccine composed of S. mutans gave significant protection against caries, a decrease in the number of S. mutans, an increase in IgG antibodies and a moderate increase in complement-fixing antibodies to LTA. When LTA was used as immunogen, there was only a small reduction in caries, without any detectable antibodies to LTA and a slight increase in IgG antibodies to cell of S. mutans. Vaccines of L. acidophilus or L. fermentum gave no protection. A combined vaccine of S. mutans and L. acidophilus did not reduce the incidence of caries but the antibody titre to cells of S. mutans was raised to a level comparable with that in the S. mutans-immunised monkeys. The results of this investigation in a subhuman primate confirm that immunisation with S. mutans induces protection against caries, unlike the attempt to immunise with two selected strains of lactobacilli. More studies are required to establish the role of specific serotypes of lactobacilli in the development of dental caries.

Animals↗
PubMed1982

Quantitative electron microscopy microscopical analysis of leukocyte infiltration in oral ulcers of Behçet's syndrome.

A stereological electron microscopical technique was applied to biopsies of oral ulcers from patients with Behçet's syndrome in order to carry out a quantitative analysis of the cellular infiltrate. The results have confirmed the light microscopical qualitative findings of a large number of lymphocytes (67%) but have established that a relatively large proportion of the leukocytes (14%( belong to the monocyte-macrophage series. The virtual absence of plasma cells during the early stages of ulceration and the presence of a large number of lymphocytes and monocytes argue in favour of a type IV cell-mediated immune reaction. As the lesion progresses a type III reaction develops and this might be associated with immune complexes found in the serum of patients with Behçet's syndrome.

Adult↗
PubMed1982

Cell-bound helper and suppressor factors in primate lymphocytes.

Cell-bound helper and suppressor factors, on lymphocytes from Rhesus monkeys, were assayed by the indirect immunofluorescent method, using F(ab')2 fragments of rabbit antisera to antigen specific secreted helper and suppressor factors. The rabbit antisera recognize the function related to the 'constant' region of secreted antigen specific helper or suppressor factor. Immunoadsorption studies suggest that the two antisera also recognize cell surface markers of helper or suppressor cell, for the activity of the anti-helper factor (HF) antiserum was adsorbed by cells from helper cell but not by suppressor cell induction cultures and the converse was found for the anti-suppressor factor (SF) antiserum. A significantly greater proportion of bound SF than HF was found in lymphocytes from controls and the converse or a greater proportion of HF and SF was found in lymphocytes from immunized monkeys. Furthermore, a significantly greater proportion of T-enriched cells bound anti-SF than anti-HF and the converse was found with T-depleted cells, suggesting that the assay detects the target cell as well as the cell of origin of these factors. A sequential in vitro comparison of cell-bound and secreted factors revealed that the highest number of cells which stained with anti-HF was on day 4 of the culture and this correlated with the highest secreted HF activity. However, cells which stained with anti-SF reached a peak on day 2, whereas maximal secreted SF activity was found on day 3. In vivo the kinetic relationships after immunization showed similar timings for the development of bound HF and SF, though the proportion of cells differed. However, the secreted HF after secondary immunization reached its highest level of activity on day 5, as compared with day 2 for cell bound HF. Both primary and secondary cellular but not antibody responses showed well defined bi-phasic responses and their significance as well as those of bound HF and SF in immunoregulation will need to be explored further.

Animals↗
PubMed1982

The relationship of HLA-B and DR phenotypes to Behcet's syndrome, recurrent oral ulceration and the class of immune complexes.

A series of eighty Caucasian patients was divided into four groups with the mucocutaneous, arthritic, neurological and ocular types of Behcet's syndrome (BS) and a fifth group of patients with recurrent oral ulcers. The immunogenetic basis of the four types of BS was extended from HLA-B locus to the DR locus. Whereas B5 and more precisely the Bw51 split is the most discriminating marker of the ocular type of BS, DR7 also shows a significant increase in the ocular and neurological types. Indeed, most if not all patients with the ocular type have B5 and/or DR7. B12 and/or DR2 is significantly increased at the less severe end of the spectrum, the mucocutaneous and arthritic types. Patients with recurrent oral ulcers also show an increase in B12 and/or DR2. However, B12 and/or DR7 shows an increase in the relative risk in all four types of BS. These results suggest that HLA-B12, B5, DR7 and DR2 might in some way be associated with tissue localization of disease. Alternatively, since patients with HLA-B12 show a significantly greater ratio of IgG:IgA circulating immune complexes than those with B5/DR7/DR2, tissue localization might be influenced by the immune complex isotype. A significant relationship was also found between the MT2 and MT3 B cell alloantigen system and BS, with particular reference to MT2 and the neurological type and MT3 and the ocular type of BS.

Antigen-Antibody Complex↗
PubMed1981

Characterization of mononuclear cells in the human oral mucosa.

A histochemical investigation of 16 sites of post-mortem oral mucosa was carried out in an attempt to define any organized lymphoid tissue in the mouth. Whereas lymphoid tissue was found, as expected, in the palatine and lingual tonsils, only 1 out of 240 specimens revealed lymphoid aggregations at other mucosal sites. However, mononuclear cells were scattered in the lamina propria of the oral mucosa and this varied from 53 cells/mm2 in the fetus to 83 cells/mm2 in old age. Non-keratinized oral mucosa showed a significantly higher number of mononuclear cells than keratinized mucosa. Up to 53 per cent of the cells stained with acid alpha naphthyl acetate esterase (ANAE), consistent with T cells, and up to 25 per cent gave a staining reaction consistent with monocytes. Some of the ANAE-negative cells were B lymphocytes. The presence of T cells was also examined by using the acid phosphatase reaction. It is suggested that, with the exception of the palatine and lingual tonsils, organized lymphoid tissue is not normally found in the rest of the mouth. However, the presence of scattered mononuclear cells at all ages and in all the sites of the oral mucosa examined suggests that these cells may provide a local surveillance mechanism.

Acid Phosphatase↗
PubMed1981

Separation and characterization of a protein antigen from cells of Streptococcus mutans.

A protein antigen, I/II, was purified from cells and culture supernatants of Streptococcus mutans (serotype c) by solubilization in urea followed by ion exchange chromatography and gel filtration. Immunological activity was retained after further purification by preparative sodium dodecyl sulphate--polyacrylamide gel electrophoresis (SDS--PAGE). The sedimentation coefficient was estimated to be approximately 8.7S by sucrose gradient centrifugation. The use of staining procedures, as well as the linear migration of this protein through different concentrations of acrylamide during SDS--PAGE, indicated that the antigen is probably not a glycoprotein. A lower molecular weight protein containing the free antigen I determinant was shown to have extensive homology with intact antigen I/II which implied that the former was a degradation product of the intact 185 000 dalton antigen I/II. Antigen II, although previously defined by its resistance to proteases, could be further digested with trypsin after denaturation by SDS--PAGE. Antigen I/II could not be correlated with a group of glucosyltransferases isolated from whole cells and culture supernatants. The cell surface location of antigen I/II was established by the lactoperoxidase-catalysed iodination of intact cells followed by protein analysis using SDS--PAGE. Previously, the potential importance of antigen I/II has been established by its immunogenicity and capacity to induce a protective immune response against dental caries.

Antigens, Bacterial↗
PubMed1981

Relationship of HLA phenotype to immunoglobulin class present in immune complexes from patients with Behçet's syndrome.

The immunoglobulin class of circulating immune complexes (IC) was examined in 35 patients with Behçet's syndrome (BS) according to the HLA phenotype of these patients. Cold precipitable complexes were separated and assayed by laser nephelometry and polyethylene glycol precipitable complexes were assayed by rocker immuno-electrophoresis for IgG, IgA and C3. The results suggest that in patients with BS, HLA-B12 is associated with an increased proportion of IgG and a decreased proportion of IgA and C3 in their immune complexes, whilst the converse was found with HLA-B5 or DRw2. The ratio of IgA:IgG in immune complexes was therefore low in patients with HLA-B12 but high in those with HLA-B5 or DRw2. We suggest that a linkage may exist between HLA and gene(s) determining the immunoglobulin class, in response to antigenic stimulation or the site of antigen localization.

Antigen-Antibody Complex↗
PubMed1981

Immunization with purified protein antigens from Streptococcus mutans against dental caries in rhesus monkeys.

Protein antigens I, I/II, II, and III were prepared from Streptococcus mutans (serotype c). Their immunogenicities and protective effects against dental caries were investigated in 40 rhesus monkeys kept entirely on a human-type diet, containing about 15% sucrose. Antigens I, I/II and, to a lesser extent, antigen II induced significant reductions in dental caries, as compared with sham-immunized monkeys. This was achieved with 1 or 2 doses of antigen, the first of which was administered with adjuvant (Freund incomplete adjuvant or aluminum hydroxide). There was no reduction in caries in monkeys immunized with antigen III. The reduction in caries in the animals immunized with antigens I or I/II was comparable to that in monkeys immunized with whole cells. Protection against caries was associated predominantly with serum and gingival crevicular fluid immunoglobulin G antibodies, which appeared to be directed against the antigen I determinant, but antibodies to antigen II, though not to antigen III, were also protective.

Animals↗
PubMed1981

Pregnancy-associated alpha-2-glycoprotein in recurrent oral ulceration and Behçet's syndrome.

Estimation of the serum concentration of pregnancy-associated alpha 2-glycoprotein (alpha 2-PAG) in male patients with recurrent oral ulcers (ROU) and Behçet's syndrome (BS) revealed significant increases in both groups of patients. The concentrations of alpha 2-PAG in 24 control subjects were less than 10 micrograms/ml, whereas 11/26 (42%; p less than 0.001) of patients with ROU and 20/33 (61%; p less than 0.0005) with BS had concentrations greater than 10 micrograms/ml. Indirect immunofluorescence staining for alpha 2-PAG on the surface membrane of blood mononuclear cells suggests that there is an increase in the number of alpha 2-PAG-positive cells in BS. It is not clear at present whether the increased concentrations of alpha 2-PAG might exert an inhibitory effect on the immune response. No correlation was observed between the levels of alpha 2-PAG in ROU and BS and concentrations of alpha 1-acid glycoprotein, C9, factor B or lysozyme. It is therefore unlikely that the increase in alpha 2-PAG is a manifestation of an increase in acute phase protein.

Behcet Syndrome↗
PubMed1981

Antigen-specific helper factor reacts with antibodies to human beta 2 microglobulin.

Antigen-specific helper factor was induced in vitro from lymphoid cells of monkeys and mice by using an antigen derived from Streptococcus mutans. Helper activity was removed from supernatants of monkey cells by affinity chromatography on Sepharose 4B insolubilized antibodies specific for human beta 2-microglobulin (H beta 2M) prepared in chicken, rabbit and rat, and an insolubilized monoclonal mouse anti-H beta 2M antibody-bound monkey helper factor activity. However, guinea pig antibody to human beta 2M was inactive. In parallel studies, the pattern of absorption of mouse helper factor (HF) was different from that of the monkey in that insolubilized guinea pig anti-H beta 2M bound helper factor, whereas rabbit and monoclonal anti-H beta 2M failed to do so. Although these findings were not compatible with an intact beta 2M chain being present in helper factor, they may imply a cross-reactivity of beta 2M with a "constant region" of helper factor that may share common sequences with beta 2M. This may suggest that factor genes have evolved from the same ancestral genes as beta 2M.

Animals↗
PubMed1981

A radioimmunoassay for serum and gingival crevicular fluid antibodies to a purified protein of Streptococcus mutans.

A solid-phase radioimmunoassay was developed to measure serum IgG antibodies to a purified protein antigen I/II prepared from Streptococcus mutans. The assay was specific to this antigen and significant binding of 125I-radiolabelled antiserum was found only in sera from rhesus monkeys immunized with the antigen I/II but not in sham-immunized monkeys or those immunized with streptococcal antigen III. A very significant correlation was found in serum IgG antibodies tested by the radioimmunoassay and an immunofluorescent technique (r = 0.88, P less than 0.001). The sensitivity of the double-layer radioimmunoassay was increased 10 times by the addition of a third antibody layer and this enabled gingival crevicular fluid antibodies to be measured. Comparison of paired samples of serum and crevicular fluid revealed a very significant correlation between IgG antibodies to streptococcal antigen I/II in the the two fluids (P less than 0.001). These findings suggest that serum antibodies can reach the tooth surface via gingival crevicular fluid.

Animals↗
PubMed1981

Different cross-reacting circulating immune complexes in Behçet's syndrome and recurrent oral ulcers.

Circulating immune complexes were isolated by 2% polyethylene glycol precipitation from the sera of 15 out of 37 patients with Behçet's syndrome and 11 out of 23 patients with recurrent oral ulcers. The antigenic cross-reactions of the polyethylene glycol precipitates were studied by coating a plastic tube with one complex and adding another 125I-labeled complex in dissociating (acid) conditions. On neutralization, partial reassembly occurred with the complex coating the tube wall, thus indicating cross-reaction with it. In the first 30 complexes studied, the cross-reactions obtained were sorted by computer program into two mutually exclusive subsets of reactions. Two similar homologous subsets of reactions were found in the second group of 29 patients: in total, nine out of 16 ocular, four out of six herpetiform circulating immune complexes in one subset, and four out of seven neurological in the other. A wider pattern of reaction could be detected in addition, which induced most of the Behçet's syndrome and recurrent oral ulcers. Immune complexes from control sera did not cross-react. An exogenous agent could account for the circulating immune complexes' cross-reactions for the group as a whole, and two antigenic determinants of that agent or antigens from different damaged tissues explain the subsets.

Antigen-Antibody Complex↗