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Query: UMLS:C0026918 (Mycobacterium)
 52,428 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In an effort to study the immunological responses to antigens of tubercle bacilli, 49 tuberculin positive and 41 tuberculin negative hospital contacts aged 20-29 years (staff nurses and students working in Government Rajaji Hospital, Madurai, South India) were studied for serum antibodies (IgG, IgM and IgA classes) to BCG by ELISA and diameter of induration to PPD by Mantoux procedures. The two immunological parameters were correlated in regression analysis. The results have revealed higher anti-BCG serum antibody levels in hospital contacts than in non-contacts, significantly higher antibodies in tuberculin negative hospital contacts than in tuberculin positive hospital contacts, an inverse correlation of tuberculin reactivity and antibodies and a bimodal decline (regression) of antibodies against the increase in skin test induration. This study has thus suggested the existence of an immunological spectrum in hospital contacts from south India; persons at one pole of the spectrum were tuberculin negative and possessed significantly elevated antibody levels and those at the other pole of the spectrum were tuberculin positive and possessed low antibody levels. Thus the spectrum of immune reactivity may be due to an inherent susceptibility/resistance of an individual to Mycobacterium tuberculosis.
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PMID:Spectrum of immune reactivity to mycobacterial (BCG) antigens in healthy hospital contacts in south India. 147 93

The production of comitogenic activity consistent with interleukin-1 (IL-1) activity by blood monocytes from cattle with naturally acquired paratuberculosis was examined by murine thymocyte proliferation. In addition, IL-1-like activity in response to homologous and heterologous antigens was determined. Activity was determined in nine cattle naturally infected with Mycobacterium paratuberculosis and six non-infected cattle. Comitogenic properties were measured in response to M. paratuberculosis antigen (johnin), bacterial lipopolysaccharide (LPS) as a positive control, and culture media as a negative control. Monocytes from infected cattle spontaneously released high levels of IL-1-like activity in the absence of stimuli and significantly (P less than 0.05) increased activity in response to LPS. With johnin, M. bovis PPD and KLH stimulation, comitogenic activity was similar to spontaneous levels. Non-infected cattle had significantly (P less than 0.05) increased comitogenic activity when blood monocytes were stimulated with KLH, M. bovis PPD, johnin, and lipopolysaccharide when compared with non-stimulated cells in that group. Johnin produced the greatest response in non-infected animals. The data suggest that blood monocytes in infected cattle are non-specifically activated with respect to IL-1 production. Alternatively, a defective regulatory mechanism for IL-1 may be operative in infected cattle. In addition, the previous observation that mycobacterial antigens are potent inducers of IL-1 was also verified.
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PMID:Spontaneous murine thymocyte comitogenic activity consistent with interleukin-1 in cattle naturally infected with Mycobacterium paratuberculosis. 194 71

Tuberculin skin test reactivity decreases with time such that repeat PPD skin testing may result in reactions of less than 10 mm. This reactivity may be boosted in some individuals with a second tuberculin skin test. The immunologic basis of these observations remains unclear. We studied the relationship between skin-test reactivity and in vitro blastogenic response to PPD in a cohort of 22 individuals (aged 28 to 81 years) known to be tuberculin reactors (induration greater than or equal to 10 mm) in 1970. In 1989, 18 subjects remained reactive to PPD on the first skin test and responded to PPD in vitro (mean incorporation of 3H-thymidine by peripheral blood mononuclear cells, 22,650 cpm). Three subjects reverted (induration in response to PPD less than 10 mm) and lost in vitro reactivity to PPD (mean incorporation of 3H-thymidine, 2,205 cpm). One subject boosted (increase of induration of at least 6 mm to greater than or equal to 15 mm) on the second skin test and showed a concomitant in vitro boost in the blastogenic response to PPD (from 1,008 cpm to 47,837 cpm). In this cohort, interpretation of the two-step tuberculin skin test correlated closely with in vitro proliferative responses. Over a 19-year period, the majority of individuals maintained skin test reactivity and strong in vitro responses to PPD despite a lack of ongoing exogenous exposure to Mycobacterium tuberculosis. The immunologic basis for reversion appears to depend in part on a loss of lymphocyte blastogenic capacity. In the one individual who exhibited the booster phenomenon, repeat antigen stimulation resulted in a dramatic increase in the in vitro blastogenic responses.
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PMID:A 19-year follow-up of tuberculin reactors. Assessment of skin test reactivity and in vitro lymphocyte responses. 201 74

We have studied proliferative responses to mycobacterial antigen preparation (PPD) and to non-specific stimuli of interstitial cells from the lungs of Mycobacterium tuberculosis-infected CBA mice. PPD-reactive lymphocytes appeared in the lung wall tissue in the course of chronic infection, but their proliferative capacity was totally inhibited by the lung macrophages. The latter were also able to suppress the proliferation of immune lymph node T cells. The mechanism of suppression clearly had two components, one being infection-specific and the other non-specific. Non-specific suppression was mediated mainly by prostaglandin E(PGE), whereas the specific mechanism showed only a weak influence of PGE and depended on the presence of I-J+ Lyt-2- nylon-wool-adherent cells in the responder population. Interstitial lung T or B lymphocytes were not involved in specific suppression.
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PMID:Regulation of T-cell proliferative responses by cells from solid lung tissue of M. tuberculosis-infected mice. 207 Nov 62

After intradermal injection of bovine purified derivative (PPD), increases in plasma fibrinogen concentration and plasma viscosity developed in red deer (Cervus elaphus) with a history of tuberculosis caused by Mycobacterium bovis. Serum haptoglobin concentrations were also found to increase under similar circumstances. The increases were reproducible and did not appear to be related to mustering, stress, or the handling associated with injection of PPD. A significant (P less than 0.05) direct relationship was found between the increase in plasma fibrinogen concentration and various markers of bovine tuberculosis infection, such as stimulation of lymphocyte transformation in response to bovine PPD and the diameter of intradermal tuberculin skin test reactions. A stronger correlation (P less than 0.01) was found with the volume of intradermal tuberculin skin test reactivity, and the strongest correlation (P less than 0.001) was with the presence of circulating antibovine PPD antibody.
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PMID:Evaluation of relationship between plasma fibrinogen concentration and tuberculin testing in red deer. 207 82

In the period from 1983 to 1986, bacteriological examination for paratuberculosis was performed in 263 samples of lymph nodes, intestinal mucous membrane and excrements of cattle, kept on a farm where clinical paratuberculosis occurred. Seventy-nine strains of mycobacteria were isolated during the culturing. On selective agar medium with mycobactin as the growth stimulator, 71 strains were isolated which had failed to grow on the conventional mycobacterium-culturing media. In the subculture, the dependence of mycobacteria on the mycobactin declined and the number of mycobacterium strains growing in the subculture on conventional mycobacting-free media doubled. Two thirds of the mycobacteria which did not depend on mycobactin during growth exhibited the same antigenic properties as Mycobacterium avium 1, 2, 3, 8 during serotypification. Ability to induce sensibility to PPD avian tuberculin or paratuberculin was demonstrated during the bioassays of mycobactin. Almost a half of the strains inducing animals' sensitivity to the above-mentioned allergens were found to be virulent to pullets that had tuberculosis in their parenchymatous organs. Of the laboratory animals, the highest virulence of the mycobactin-dependent mycobacterium strains was demonstrated in mice subjected to intravenous infection, accompanied by hyperplasia of the spleen, with reisolation of the mycobacterium culture within six eight weeks after infection.
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PMID:[Biologic characteristics of mycobacterium strains isolated from cattle from herds with clinical paratuberculosis]. 210 Apr 29

Both macro- and micronutrients have been shown to affect resistance to tuberculosis, which is mediated by macrophages activated by T lymphocytes. Others have demonstrated inhibition of mycobacterial replication in macrophage cultures treated with vitamin D or retinoic acid. We examined the influence of dietary zinc and vitamin D on resistance to tuberculosis. Guinea pigs were fed diets containing varying levels of zinc or vitamin D, and infected 6 weeks later by the respiratory route with virulent Mycobacterium tuberculosis. Zinc-deficient guinea pigs had fewer circulating T cells and reduced tuberculin (PPD) hypersensitivity. The response of peritoneal exudate macrophages to the lymphokine MIF was impaired. Zinc deprivation did not influence disease resistance in BCG-vaccinated or nonvaccinated animals. Vitamin D deficiency adversely affected the tuberculin reaction and ability to control the infection. Lymphocytes from vitamin D-deprived animals did not proliferate normally when cultured with PPD. A diet supplemented with vitamin D enhanced T cell responses to PPD in vivo. These results suggest that zinc and vitamin D status affect immunity to tuberculosis.
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PMID:Micronutrient status and immune function in tuberculosis. 211 88

A component of Mycobacterium tuberculosis H37Rv PPD referred as C3Ag was purified with a column of affinity chromatography to which a monoclonal antibody (TB-15C3) was conjugated. C3Ag was found to have two bands in 56,000 and 66,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Western blot revealed that both fragments were recognized by TB-15C3. By ELISA C3Ag was shown to react with rabbit antisera against M. tuberculosis, M. Kansasii, M. screfulaceum, M. bovis BCG, but not to react substantially with antiserum against M. bovis. Among 82 sera from patients with pulmonary tuberculosis 60% showed positive reactions to C3Ag while for 100 normal control sera it was only 10%. C3Ag elicited a delayed cutaneous reaction in guinea pigs sensitized with heat killed M. tuberculosis, M. bovis and BCG. These results suggest that C3Ag might be an important fragment of H37Rv PPD.
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PMID:[Purified protein derivative antigen purified by using a monoclonal antibody to Mycobacterium tuberculosis]. 212 13

In vitro proliferative response of lung cells from mice infected with Mycobacterium tuberculosis H37Rv against PPD and Con A was studied. It was shown that the infected lung contained immune T cells, but their response in vitro was totally inhibited by plastic and nylon wool adherent suppressor cells. The whole population of lung cells from infected, but not intact mice, efficiently suppressed the proliferative response of immune lymph node cells against various antigens (non-specific suppression). The inhibition of response again depended on the presence of plastic adherent lung cells. Our data suggest that at least two suppressor pathways are induced in the course of tuberculosis infection: one being specific for mycobacterial antigens and other non-specific. Both types of suppressor pathways depend on the plastic adherent lung cells from tuberculosis lesion.
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PMID:[Suppression of immune response by lung cells in experimental tuberculosis]. 214 88

The cytolytic capacity of mycobacterial antigen-stimulated peripheral blood mononuclear cells, from healthy Mantoux-positive volunteers and from patients with tuberculosis was investigated. Polyclonal T cell lines induced by 7 days of stimulation in vitro with PPD or a sonicate of Mycobacterium tuberculosis lysed both autologous macrophages and Epstein-Barr virus (EBV) transformed B cell lines which had been pulsed with mycobacterial antigens, to a greater extent than unpulsed target cells or target cells pulsed with an irrelevant antigen (streptokinase/streptodornase). The killing of mycobacterial antigen-pulsed macrophages and EBV-transformed B cell line targets was inhibited by monoclonal antibodies to MHC class II antigens but not by antibodies directed against MHC class I antigens. PPD-pulsed EBV-transformed lymphoblastoid cell lines (LCL) competitively inhibited the killing of mycobacterial antigen-pulsed macrophages, whereas natural killer (NK) sensitive K562 cells (with or without antigen pulsing) did not inhibit mycobacterial antigen-dependent cytolysis of macrophages. Patients with tuberculosis showed a spectrum of mycobacterial antigen-induced cytolytic capacity. Those with extensive tissue necrosis (e.g. cavitatory pulmonary tuberculosis or caseous, extrathoracic tuberculosis) had high levels while patients with disseminated (miliary) tuberculosis or disease refractory to treatment showed little evidence of mycobacterial antigen induced cytotoxicity. The ability of mycobacterial antigen-stimulated lymphoblasts to kill specific antigen-pulsed autologous macrophages was not significantly different between healthy donors and patients with tuberculosis. However, the 'mycobacterial antigen-specific' component of this cytolysis was significantly deficient (P less than 0.01) in patients. We conclude that mycobacterial antigen-specific cytotoxic T cell responses may play a significant part in the immune response to mycobacterial infection.
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PMID:Specific lysis of mycobacterial antigen-bearing macrophages by class II MHC-restricted polyclonal T cell lines in healthy donors or patients with tuberculosis. 216 2


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