Biomedical subjects

M M Simon

Publications and source records attributed to M M Simon.

At least 91 records · Page 5Linked to original sources

PubMed1992

Alpha 2-macroglobulin and alpha 2-macroglobulin/proteinase complexes in human seminal fluid.

OBJECTIVE: To determine the broad-spectrum proteinase inhibitor alpha 2-macroglobulin (alpha 2M) and its functional subforms, i.e., free alpha 2M and alpha 2M/proteinase complexes, in human seminal fluid by using specific enzyme immunoassay systems. SETTING: The study has been performed in the Andrology Department of the Dermatology Clinics and the Laboratory of Immunopathology of the Institute of Immunology. PATIENTS, PARTICIPATES: Routine patients attending the Andrology Department. INTERVENTIONS: The data have been obtained without particular interventions before or after collection of seminal fluid. MAIN OUTCOME MEASURES: The aim of the study was to determine whether alpha 2M or alpha 2M/proteinase complexes are present in human seminal fluid. RESULTS: The concentration of total alpha 2M in human seminal fluid ranged from 1 to greater than 1,000 ng/mL, and between 56% and 85% of the inhibitor was complexed with proteinases. CONCLUSIONS: These findings show that alpha 2M and alpha 2M/proteinase complexes have to be considered as functionally relevant biomolecules in male genital tract secretions.

Endopeptidases↗

PubMed1991

Coordinate secretion and functional synergism of T cell-associated serine proteinase-1 (MTSP-1) and endoglycosidase(s) of activated T cells.

Cell lysates and exocytosed soluble mediator(s) (ESM) released from CD8+ T cell lines (TCL) by receptor-triggered secretory exocytosis were tested for degradation of proteoglycans associated with in vitro produced subendothelial extracellular matrix (ECM). ESM was found to release low-molecular weight (kav 0.5-0.6) fragments from the sulfated proteoglycans in ECM. In the presence of heparin, an inhibitor for endoglycosidase activity, only high-molecular-weight products (kav 0.2) were formed. Preincubation of ESM with HD-prolylphenylalanyl-arginyl-chloromethylketone (PFR-CK) an inhibitor for the T cell-associated serine proteinase-1 (MTSP-1) totally prevented release of high- and low-molecular weight proteoglycan fragments. Furthermore, it was shown that purified MTSP-1 is able to release from ECM high-molecular weight proteoglycans and that this process is inhibitable by PFR-CK but not by heparin. Further treatment of these soluble high-molecular weight sulfated proteoglycans with ESM from TCL 1.D9 led to appearance of low-molecular weight split products (kav 0.5-0.6). This conversion was inhibitable by heparin but not by PFR-CK. These findings indicate that activated T cells contain two enzymatic activities, i.e. MTSP-1 and at least one endoglycosidase, which after receptor-triggered secretion can synergize in the degradation of sulfated proteoglycans in subendothelial ECM.

Animals↗

PubMed1991

Experimental Borrelia burgdorferi infection in inbred mouse strains: antibody response and association of H-2 genes with resistance and susceptibility to development of arthritis.

We have investigated the specific humoral immune response and its correlation to the development of disease after experimental inoculation of B. burgdorferi in different inbred strains of mice. All mouse strains tested showed high levels of specific IgM antibodies during the initial 10 days of infection. Specific IgG antibodies predominantly of the IgG2a, IgG2b and IgG3 isotypes were found in increasing amounts by 14 days post infection. Antibody titers peaked at days 65 and 110. Particularly low titers of specific IgM and/or IgG antibodies were detected in sera of AKR/N and B10.BR mice. Antibodies specific for numerous B. burgdorferi antigens including the outer surface proteins A (31 kDa) and B (34 kDa) and a protein(s) of molecular mass of approximately 40 kDa, most probably 41 kDa (flagellin) and/or 39 kDa (p39), were induced in all inbred mouse strains within 2 weeks inoculation albeit in varying concentrations. Later during infection, the patterns of antibody specificities were much more complex. With regard to development of disease all strains of mice tested fall into three groups: (a) mice of H-2k haplotype (AKR/N, C3H/HeJ, C3H/HeN, B10.BR) developed a chronic progressive arthritis in the tibiotarsal joints, (b) mice of H-2 haplotypes, H-2b (C57BL/6), H-2j (B10.WB), H-2r (B10.R111) and H-2s (B10.S) developed arthritis of variable duration and intensity which was not progressive and (c) mice of H-2d haplotype (BALB/c, DBA/2, C.B-17, B10.D2, Cal.20), irrespective of their background genes or Igh allotype, showed no clinical signs of arthritis at any time point following inoculation of B. burgdorferi organisms. The finding of similar patterns of apparently protective antibodies in all mouse strains tested together with the striking association between the H-2d haplotype and resistance, and between the H-2k haplotype and the occurrence of B. burgdorferi-induced arthritis suggest a critical role of T cells in the development of the disease in mice.

Animals↗

PubMed1991

A mouse model for Borrelia burgdorferi infection: approach to a vaccine against Lyme disease.

Lyme disease is the most common vector-transmitted illness in the USA and Europe. The pathogen, Borrelia burgdorferi, causes a complex spectrum of disease that affects the skin, joints, nervous system and heart. Patients in the early stages of the disease can often be successfully treated with antibiotics but this becomes less reliable as the disease progresses. The specific immune responses that are detectable in patients with Lyme disease are not sufficient to protect against illness; a vaccine against the infectious agent is, therefore, desirable. In this article Markus M. Simon and colleagues present a mouse model of Borrelia burgdorferi infection. Their work suggests that the outer surface protein A (OspA) of Borrelia burgdorferi may be a suitable vaccine candidate.

Animals↗

PubMed1991

Recombinant outer surface protein a from Borrelia burgdorferi induces antibodies protective against spirochetal infection in mice.

The outer surface protein A (OspA) of Borrelia burgdorferi was isolated in its native form from strains ZS7 and B31 and as a recombinant protein from strain ZS7. Amino acid sequence analysis of internal peptides of native OspA (strain ZS7) revealed identity with the sequence deduced from the OspA gene. Repeated immunization of C57BL/6 and C.B-17 mice with any of the three OspA structures resulted in the generation of monospecific hyperimmune sera reactive with both native and recombinant OspA. Upon transfer of immune sera specific for either native OspA (strain B31) or recombinant OspA (strain ZS7) but not of those reactive with the recombinant 41-kDa flagellin-associated antigen, severe combined immunodeficient (SCID) mice were completely protected against infection with strain ZS7. The finding that monoclonal antibodies to OspA and to OspB but not to non-outer surface spirochetal structures such as flagellin, p20, p65, and p70 conferred protection in SCID mice makes OspA (and possibly OspB) a promising candidate vaccine against Lyme disease.

Amino Acid Sequence↗

PubMed1991

In vivo primed mouse T cells selectively express T cell-specific serine proteinase-1 and the proteinase-like molecules granzyme B and C.

Previous studies have shown that mouse CD8+ T lymphocyte clones (TLC) produce T cell-specific serine proteinase-1 (MTSP-1) as well as a family of six homologous molecules, termed granzymes B - G, which are structurally related to serine proteinases. Of these proteins, only MTSP-1 has been studied in detail. It has been shown to occur in the majority of CD8+ and a fraction of CD4+ T effector cells in vivo and in vitro and has demonstrable enzyme activity in these cells. The presence of the other serine proteinase-like molecules in T cells is less well defined. We have now analyzed the expression of mRNA species specific for granzymes B - G in activated T cell populations using the sensitive polymerase chain reaction which allows the detection of mRNA species from as little as 2 pg of total cytoplasmic RNA. We demonstrate that MTSP-1 and all six serine proteinase-like transcripts are expressed in a panel of four CD8+ and six CD4+ long-term-cultured TLC, though at greatly differing concentrations. In contrast, in vivo primed T cells of both phenotypes, CD4+ and CD8+, and in vitro activated T cells derived from short-term cultures only express mRNA species specific for MTSP-1 and CCP1 and little of those for CCP2, but no transcripts for granzymes D - G. These findings argue against the participation of granzymes D - G in T cell-mediated functions in vivo.

Animals↗

PubMed1991

Immunogold labeling of perforin and serine esterases in granulated metrial gland cells.

Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells are cytolytic lymphocytes known to produce a pore-forming protein, named perforin or cytolysin, that lyses target cells by creating large pores on the target plasma membrane. Besides perforin, the granules of CTL and NK cells contain a family of serine esterases. Perforin has also been localized in granulated metrial gland (GMG) cells of the murine embryo implantation site by light microscopic immunostaining. Ultrastructural immunogold labeling with antibodies against perforin and a serine esterase (MTSP 1 or granzyme A) shows that GMG cells contain both perforin and serine esterases in the fine granular matrix of their granules. Perforin has been located in all of the granules, whereas gold particles corresponding to serine esterases have been found in most of the granules. Results from the double immunogold technique indicate that perforin and serine esterases colocalize to most of the same granules in GMG cells. This study supports the view that GMG cells are related to cytolytic lymphocytes.

Animals↗

PubMed1991

Expression of T-cell-associated serine proteinase 1 during murine Leishmania major infection correlates with susceptibility to disease.

The expression of T-cell-associated serine proteinase 1 (MTSP-1) in vivo during Leishmania major infection was analyzed in genetically resistant C57BL/6 mice and in genetically susceptible BALB/c mice. Using a monoclonal antibody as well as an RNA probe specific for MTSP-1 to stain tissue sections, we found T cells expressing MTSP-1 in skin lesions and spleens of mice of both strains. In skin lesions, MTSP-1-positive T cells could be detected as early as 3 days after infection. Most importantly, the frequency of T cells expressing MTSP-1 was significantly higher in susceptible BALB/c mice than in resistant C57BL/6 mice. These findings suggest that MTSP-1 is associated with disease-promoting T cells and that it may be an effector molecule involved in the pathogenesis of cutaneous leishmaniasis.

Animals↗

PubMed1991

Myositis in mice inoculated with Borrelia burgdorferi.

The authors describe the appearance of myositis in immunocompetent and immunodeficient mice after subcutaneous inoculation with Borrelia burgdorferi by histology and immunohistology. Experimental infection of mice 1) causes inflammation of striated but not smooth muscles, 2) affects the entire musculoskeletal system, and 3) is characterized by perivascular and interfacicular infiltration of mononuclear leukocytes in the striated muscle leading to necrosis as well as disruption of muscle fibers. The lesions found in striated muscle specimens were most pronounced in immunodeficient (SCID), less severe in T-cell-deficient nu/nu (BALB/c, C57BL/6) and marginal to moderate or almost not present in immunocompetent AKR/N and C.B-17 mice, respectively.

Animals↗

PubMed1991

[Borrelia burgdorferi infection. II. Aspects of basic research, new approaches to diagnosis and therapy].

In this review article, current thinking about the infection caused by Borrelia burgdorferi is presented. The problems associated with diagnosis and treatment of Borrelia burgdorferi infection are pointed out. A series of monoclonal antibodies recognizing Borrelia burgdorferi-associated antigens is presented. In collaborative research projects these antibodies have been used for molecular biological (cloning and sequencing of Borrelia burgdorferi antigens) and immunological (protection experiments by passive transfer of monoclonal antibodies in an animal model) experiments. Taken together, these studies disclosed new aspects for diagnosis and therapy of the Borrelia burgdorferi infection. In this second part of the review article the above-mentioned molecular biological and protection experiments are summarized.

Amino Acid Sequence↗

PubMed1991

Mouse T-cell associated serine proteinase 1 degrades collagen type IV: a structural basis for the migration of lymphocytes through vascular basement membranes.

We show that CD8+ T-lymphocyte lines perferentially attach to collagen type IV and that mouse T-cell specific serine proteinase 1 (MTSP-1) preferentially degrades native basement membrane collagen type IV. In contrast, the interstitial collagen types I, II, III, V and VI appear not to be affected. The data reveal that MTSP-1 predominantly cleaves the alpha 2(IV) chain, which is found in the native triple helical structure of type IV collagen in a ratio of alpha 1(IV): alpha 2(IV) = 2:1 into small peptides. The cleavage of the alpha 2(IV) chain within the native collagen type IV molecules most likely results not only in a destabilization of single molecules but of the entire collagenous basement membrane scaffold at the site of MTSP-1 secretion.

Animals↗

PubMed1991

A mouse model for Borrelia burgdorferi infection: pathogenesis, immune response and protection.

Viable Borrelia burgdorferi (B. burgdorferi) organisms induce a chronic infection associated with arthritis, carditis and hepatitis in severe combined immunodeficiency (scid) mice but not in most of the adult mice from the various immunocompetent inbred strains tested. Furthermore, we have found that experimental inoculation of normal mice with B. burgdorferi organisms leads to the generation of antibodies and T cells specific for various spirochetal antigens including the outer surface proteins A and B (OspA, OspB) as well as flagellin. The assumption of a protective role of the immune response during B. burgdorferi infection in mice is supported by our recent findings that passively transferred B. burgdorferi-specific immune mouse sera as well as monoclonal antibodies to OspA are able to prevent the development of the disease in scid mice. We show now that purified OspA protein both in its native and recombinant form is immunogenic and that the antibodies generated are able to confer protection to scid mice against B. burgdorferi infection.

Animals↗

PubMed1990

Measurement of free human leukocyte elastase and human leukocyte elastase/alpha 1 proteinase inhibitor complexes by an enzyme-linked immunosorbent assay.

We report on an ELISA procedure for the quantitative analysis of total human leukocyte (PMN)-elastase, i.e., the simultaneous determination of (i) free (non-complexed) PMN-elastase and of (ii) PMN-elastase that is complexed to alpha 1 proteinase inhibitor. Simultaneous detection of both forms of PMN-elastase was achieved using a monoclonal antibody that recognizes a PMN-elastase-specific epitope present on both the uncomplexed and the complexed form of the enzyme. The test system described is reliable, easy to perform and permits the determination of total PMN-elastase in complex biological fluids such as plasma or seminal fluid. It is to be expected that this test system will be useful for investigations of human PMN-elastase in biological specimens obtained from both normal and pathological conditions.

Antibodies, Monoclonal↗

PubMed1990

Quantification of free alpha 2-macroglobulin and alpha 2-macroglobulin-protease complexes by a novel ELISA system based on streptococcal alpha 2-macroglobulin receptors.

An ELISA test system has been developed for the quantification of the two distinct forms of the proteinase inhibitor alpha 2-macroglobulin (alpha 2M): (i) free alpha 2M (functionally active), which is the electrophoretically slow form (alpha 2 MS), and (ii) the alpha 2 M-proteinase complex (functionally inactive), which is the electrophoretically fast form of alpha 2 M (alpha 2 MF). Discrimination between the two types of alpha 2 M was achieved using extracts of the two independent streptococcal strains, M1 and Sc1, which express receptors for alpha 2 MS and alpha 2 MF, respectively, in combination with a monoclonal antibody specific for alpha 2 M. The assay system described is easy and reliable and permits quantitation of alpha 2 MS and alpha 2 MF in complex biological samples such as plasma and cutaneous suction blister fluid.

Blister↗

PubMed1990

Activation of pro-urokinase by the human T cell-associated serine proteinase HuTSP-1.

The human T cell-associated serine proteinase-1 (HuTSP-1) is expressed by activated T lymphocytes and is exocytosed upon their interaction with target cells. Here, we report that HuTSP-1 is able to convert single-chain human pro-urokinase into the active two-chain enzyme. Time-dependent activation by HuTSP-1 of recombinant human pro-urokinase as well as natural pro-urokinase derived from human melanoma cells was demonstrated in a chromogenic assay specific for active urokinase type plasminogen activator and in immunoblotting experiments revealing the conversion of single-chain into two-chain urokinase. Control experiments excluded plasmin as the activating agent. These data suggest a novel pathway for plasmin generation during T cell-mediated processes such as immune responses and extravasation of immune cells.

Enzyme Activation↗

PubMed1990

Lyme carditis in immunodeficient mice during experimental infection of Borrelia burgdorferi.

Recently, we described the severe combined immunodeficiency (scid) mouse as a laboratory model for B. burgdorferi infection. Scid mice inoculated with the virulent low-passage tick isolate Borrelia burgdorferi ZS7 developed a severe pancarditis involving endocardium, myocardium and epicardium in the absence of functional B- or T-cells. Soon after inoculation perivascular infiltration was observed, later diffuse infiltration of the interstitium of the subendocardial and subepicardial areas was seen. The infiltrate was mainly mononuclear and predominantly composed of Mac-1+ cells. Concomitantly, fibroblast proliferation and augmented collagen deposition occurred in the interstitium. This was associated with the presence of B. burgdorferi organisms. The histopathological and ultrastructural findings observed in scid mice resemble those observed in human Lyme carditis. The data emphasize the suitability of the scid mouse as a model in which to study the role of the immune system in the pathogenesis of Lyme carditis.

Animals↗

PubMed1990

Characterization of Borrelia burgdorferi associated antigens by monoclonal antibodies.

In this paper, we present a series of murine mAb recognizing B. burgdorferi antigens. The antibodies were characterized by immuno-blotting and immuno-fluorescence studies using isolates of B. burgdorferi from North America and Europe, respectively. Moreover, reactivity of the antibodies with recombinant B. burgdorferi flagellin and OspA was studied. The results suggest these anti-B. burgdorferi mAb as valuable tools for the serological analysis of B. burgdorferi isolates and for affinity-purification of the respective proteins. Moreover, these mAb appear suitable to classify antigenic variants of B. burgdorferi and to study the protective capacity of antibodies in a murine model for B. burgdorferi infection.

Animals↗

PubMed1990

Monoclonal antibodies specific for the outer surface protein A (OspA) of Borrelia burgdorferi prevent Lyme borreliosis in severe combined immunodeficiency (scid) mice.

We have recently shown that viable Borrelia burgdorferi organisms induce a chronic infection associated with arthritis and carditis in severe combined immunodeficiency (scid) mice but not in immunocompetent mice. The disease is similar to that found in patients suffering from Lyme disease. We now show that B. burgdorferi-specific immune mouse sera as well as a monoclonal antibody to the spirochetal outer surface antigen A (31 kDa) but not monoclonal antibodies specific for the 41-kDa antigenic component of the periplasmic flagella are able to prevent (or mitigate) the development of the disease in scid mice when passively transferred at the time of the bacterial inoculation. The identification of a B. burgdorferi-associated protective antigen suggests that the corresponding spirochetal protein should be tested as a vaccine against Lyme disease.

Animals↗