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Query: UMLS:C0026936 (Mycoplasma)
 14,761 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A Mycoplasma arginini strain, found to contaminate a T-T hybridoma designated TUH-14, was the source of a lymphokine-like activity with an ability to stimulate B-blasts to proliferate. Maturation to immunoglobulin secretion induced by the mycoplasma alone was low compared with induction by lipopolysaccharide (LPS), but could reach the same levels achieved with LPS by the addition of a B-cell maturation factor obtained from lectin-activated EL-4 thymoma cells. The mitogenic effect on B-cells was found only in the strain isolated from TUS-14; three other M. arginini strains were negative. Both mitogenic and nonmitogenic mycoplasma membrane preparations displayed higher affinity for B-cells than for T-blasts. However, membranes from the mitogenic strain, the TUH-14 isolate, bound better to activated blasts than to small resting cells, in contrast to the nonmitogenic strain G-230.
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PMID:Lymphokine-like activity of a strain of Mycoplasma arginini. 633 70

Using lectin-free IL-2 as the only initial stimulus, bulk cultures and T-cell clones were established from synovial fluid (SFL) and peripheral blood lymphocytes (PBL) of a patient with rheumatoid arthritis (RA). The cloning efficiency of growing bulk cultures was 3%-4% as evaluated by Poisson statistics and was not enhanced by the addition of autologous synovial fluid or serum. The majority of the cloned T cells expressed the OKT8+ phenotype; several clones were OKT4+ and one clone expressed OKT8+ and OKT4+ antigens. None of the cloned T cells exhibited high NK or lectin-dependent cytotoxicity, although bulk cultures had high NK activity. In primed lymphocyte typing responses, bulk cultures and two T-cell clones established from rheumatoid SFL and PBL showed consistent autoreactivity, which we have never before observed with MLC-derived bulk cultures and T cell clones. One of the autoreactive rheumatoid T-cell clones (B25) was found to provide strong helper activity to autologous B cells in the absence of mitogen. Attempts to reveal reactivity of RA-derived T-cell clones to microbial antigens have so far only been successful with Mycoplasma pneumoniae preparations. Careful analysis of this reactivity revealed, however, that Mycoplasma pneumoniae induces a stimulator cell-dependent mitogenic effect rather than an antigen-specific MHC-restricted T-cell proliferation.
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PMID:Analysis of T-cell cultures and clones from a patient with classic rheumatoid arthritis--evidence for the existence of autoreactive T-cell clones in blood and synovial fluid. 633 24

The mechanism(s) of interaction between Mycoplasma pulmonis and eucaryotic cells was studied by adherence to and hemagglutination of erythrocytes. Simple and complex carbohydrates and glycoproteins were unable to inhibit either adherence or hemagglutination, indicating that neither was a lectin activity. Both interactions appeared to be hydrophobic due to their requirement for salt and their sensitivity to temperature. Hemagglutination, but not adherence, was inhibited by both trypsin and glutaraldehyde treatment of the mycoplasma, suggesting that adherence and hemagglutination are qualitatively different. The erythrocyte receptor sites for the two activities were also separable since hemagglutination, but not adherence, required trypsinization of erythrocytes. The hemagglutinin was shown to be an integral mycoplasma component and not a broth contaminant. Once removed, hemagglutinating activity could not be replenished by incubation in serum or broth at 4 degrees C, but could be regenerated during protein synthesis under nonreplicative conditions. Thus, a mycoplasma membrane protein was detected which was capable of interacting with opposing membrane surfaces through hydrophobic interactions. Consequently, a multiphasic model of M. pulmonis-eucaryotic cell interactions was proposed.
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PMID:Multiphasic interactions of Mycoplasma pulmonis with erythrocytes defined by adherence and hemagglutination. 671 40

A 90 kDa protein of Mycoplasma salivarium was released from cell membranes of the organism with Triton X-100 and purified by ion-exchange chromatography and chromatofocusing. The protein was eluted at pH 5.5 by chromatofocusing. The protein was shown to react with the Fc fragments of IgG from human and nine different animal species and did not distinguish between IgG from different species, while protein A, tested for comparative purposes, displayed a strong specificity for human and swine IgG. Furthermore, the protein reacted with antigen specific goat IgG (specific for gamma chains of human IgG), sheep red blood cells (SRBC) sensitized with rabbit antiserum to SRBC, that is, the Fc part of rabbit IgG, and concanavalin A as well. These findings may suggest that the protein is a lectin which binds the carbohydrate moiety of the Fc part of IgG.
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PMID:Purification and characterization of membrane protein (90 kDa) from Mycoplasma salivarium, which binds immunoglobulin (Ig) G Fc fragment. 752 37

Interaction of cells of mollicutes Acholeplasma laidlawii PG 8, A. laidlawii var. granulum 18, Mycoplasma hominis PG 21, M. pneumoniae FH, M. fermentans PG 118 and their extracellular products with different carbohydrates, plant lectins of different carbohydrate specificity with glycocalix carbohydrates of the same microorganisms has been studied. Basing on this study and data from literature a conclusion is made that such phenotypical characteristics as the ability to form extracellular fructose-1.6-diphosphate specific lectin and N-acetylneuraminic acid as the end sugar in the composition of carbohydrates of mollicute glycocalyx can serve a phylogenetic marker. These markers indicate the possible origin of mollicutes from bacteria of the group Bacillus-Lactobacillus-Streptococcus as a result of degenerative evolution and are their rather stable characteristics. Such marker as extracellular lectin specific to fructoso-1.6-diphosphate which is formed by phytopathogenic mollicute A. laidlawii var. granulum, 118 evidences that in spite of genetic affinity of this "yellow" agent of cereals with A. laidlawii, it does not descend from the last ancestor directly, but they probably have some general ancestor. We do not know yet this ancestor which is a link in the evolution chain of acholeplasmas in the process of their origin from the mentioned group of bacteria. It is supposed that these markers together with such known phylogenetic markers as lactate dehydrogenase which is activated by fructoso-1.6-diphosphate, and aldolases and glycolipids with specific properties can additionally evidence for the origin of mollicutes and their affinity to certain groups of microorganisms.
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PMID:[The phenotypic traits of Mollicutes as their possible phylogenetic markers]. 765 55

This paper reports on the preparation and characterization of certain bioadhesive model drug deliver systems formed by a carrier (e.g. modified nanoparticles of polystyrene) and a ligand (e.g. tomato lectin, asparagus pea lectin, Mycoplasma gallisepticum lectin or albumin). Three different manufacturing methods (carbodiimide and glutaraldehyde coupling and physical adsorption) were studied. The activity of the lectin-latex conjugates and albumin-latex conjugate (control) were tested with gastric pig mucin. The manufacturing method had an insignificant effect on the activity, but all lectin-latex conjugates interacted two or three times more with mucin than with the control.
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PMID:Preparation and characterization of lectin-latex conjugates for specific bioadhesion. 783 37

Mono Mac 6 is a human monocytic cell line with several features of mature blood monocytes such as CD 14 antigen expression, phagocytotic ability, and the functional ability to produce cytokines. This line is often used as an in vitro model to demonstrate the actions of monocytes. In our study, the production of cytokines by Mono Mac 6 cells in response to various stimulants was analyzed and compared to that of mature monocytes in peripheral blood mononuclear cells (PBMC). Interestingly, the Mono Mac 6 cells produced IL-1 alpha/beta, IL-6, and TNF-alpha after induction with the lectin phytohaemagglutinin A (PHA), mainly known as a T cell activator. The amount of cytokine release did not decrease in the presence of polymyxin B (Pmb), an inhibitor of LPS-induced effects. Kinetic studies revealed maximum cytokine levels 24h after stimulation, whereas human PBMC produced higher yields of all cytokines and enhancement was observed up to 48 hours after induction. Stimulation with the superantigen derived from the supernatant of mycoplasma arthritidis (MAS) induced expression of IL-1 beta, IL-6, and TNF-alpha, whereas staphylococcus enterotoxin B (SEB) did not induce any cytokine release. Further experiments analyzed the ability of Mono Mac 6 cells to produce IFN-alpha which is an important characteristic of mature monocytes. The cells were induced either with inactivated Newcastle Disease Virus (NDV), Sendai Virus, or the synthetic stimulus poly I:C IFN-alpha expression was not detected on the transcriptional or the protein level. In addition, no co-expression of IL-1 and IL-6 was observed in response to these stimuli. Since NDV, Sendai Virus, and poly I:C represent strong IFN-alpha inducers in peripheral blood monocytes, these data indicate that Mono Mac 6 cells lack the ability to express IFN-alpha. In conclusion, our findings show that this cell line is a potent cytokine producer, but the capacity to produce IFN is apparently deficient.
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PMID:Cytokine production of the human monocytic cell line Mono Mac 6 in comparison to mature monocytes in peripheral blood mononuclear cells. 822 90

Mycoplasma arthritidis, an agent of chronic proliferative arthritis of rodents, secretes a potent soluble superantigen, MAM, that is active for both murine and human T and B lymphocytes. We now report the complete nucleotide and amino acid sequence of MAM and show it to be distinct from other proteins and not closely related phylogenetically to other superantigens. Two functional domains on MAM are identified based on the ability of peptides encompassing these regions to inhibit lymphocyte proliferation by the intact MAM molecule. One of these domains shares short sequences or epitopes with other microbial superantigens. The second domain contains the consensus legume lectin motif-beta, which is important for T cell activation by concanavalin (Con) A. MAM and Con A peptides containing this motif are functionally cross reactive, suggesting a novel secondary pathway for T cell activation by MAM.
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PMID:The sequence of the Mycoplasma arthritidis superantigen, MAM: identification of functional domains and comparison with microbial superantigens and plant lectin mitogens. 864 52

A better vaccine than the existing ones against contagious bovine pleuropneumonia (CBPP) caused by Mycoplasma mycoides subsp. mycoides small colony type (MmmSC) would improve the chances for eradication of CBPP. In such an effort, immunostimulating complexes (ISCOMS) have been prepared from the whole detergent-solubilized cells of MmmSC and characterized biochemically and immunologically. The most efficient detergent for solubilization of the mycoplasma was MEGA-10 which yielded a high recovery of proteins in the ISCOMS. The ISCOMS showed the typical cage-like structure by EM and sedimented as 19S by sucrose gradient centrifugation. The protein pattern of the ISCOMS, analyzed in SDS-PAGE, revealed a great number of bands distributed along the gel as high and low molecular weight polypeptides. The Western blot developed with a serum from a CBPP infected animal detected a reduced number of polypeptides. In samples from whole mycoplasma cells and in ISCOMS, lectin blots revealed more than 20 carbohydrate structures. The ISCOMS induced a strong primary antibody response in mice measured by ELISA and the boost resulted in a 6-fold increase of the serum antibody response. The IgG response was distributed into various IgG subclasses with high IgG1, IgG2a and IgG2b titres while the IgG3 response was low. In cattle the ISCOM vaccine induced strong primary and long lasting secondary antibody responses of similar magnitudes as those of naturally infected animals as recorded by ELISA which persisted more than a year. IgG response was equally distributed in IgG1 and IgG2 subclasses. Also a cell-mediated immune response measured by proliferation assay was induced by low dose of ISCOMS. In the growth inhibition test, sera from vaccinated cattle readily inhibited colony growth already after the first immunization.
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PMID:ISCOM vaccine against contagious bovine pleuropneumonia (CBPP). 1. Biochemical and immunological characterization. 943 24

Chronic inflammation is associated with blood vessel proliferation and enlargement and changes in vessel phenotype. We sought to determine whether these changes represent different types of angiogenesis and whether they are stimulus dependent. Chronic airway inflammation, produced by infection with Mycoplasma pulmonis, was compared in strains of mice known to be resistant (C57BL/6) or susceptible (C3H). Tracheal vascularity, assessed in whole mounts after Lycopersicon esculentum lectin staining, increased in both strains at 1, 2, 4, and 8 weeks after infection, but the type of vascular remodeling was different. The number of vessels doubled in tracheas of C57BL/6 mice, with corresponding increases of capillaries and venules. In contrast, neither the number nor the length of vessels changed in C3H mice. Instead, vessel diameter and endothelial cell number doubled, and the proportion of venules doubled with a corresponding decrease of capillaries. Although the infection had no effect on baseline plasma leakage, in both strains it potentiated the leakage produced by substance P. We conclude that the same stimulus can result in blood vessel proliferation or enlargement, depending on the host response. Endothelial cells proliferate in both cases, but in one case new capillaries form whereas in the other capillaries convert to venules.
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PMID:Angiogenesis in mice with chronic airway inflammation: strain-dependent differences. 977 35


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