摘要:

AbstractPurified plant protein, Trichosanthin (TCS), was partially digested with chymotrypsin to produce peptide fragments. Two large fragments, I and II, have been isolated and identified as C-terminal peptides located at sequence positions between 79–234 and 107–234, Their molecular weights determined by electro-phoretic mobility on SDS gel were 16,000 and 14,000 daltons. Studies using fluorescence quenching measurements by titrating anti-TCS Fab with TCS and fragment I and II showed that four epitopes were present in intact TCS and one each epitope in fragment I and II. One of the epitopes is therefore located between sequence positions 107 and 234.

ISSN:0892-3973    

DOI:10.3109/08923978809014328

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractWe studied the effects of the gold compound sodium aurothionalate (SATM) on the responses of murine CTLL2 cells, and human T cells to Interleukin-2 (IL-2). SATM inhibited tritiated thymidine (3HTdR) incorporation by CTLL2 cells stimulated with human recombinant IL-2. Human T cells were cultured with phytohemagglutinin (PHA) in separate experiments and IL-2 receptor expression measured by using immunofluorescent anti-Tac serum; SATM inhibited IL-2 receptor expression. Furthermore, SATM when added concurrently with PHA, and IL-2 inhibited3HTdR incorporation by human T cells in 5 day cultures. The kinetics of inhibition were further studied by adding PHA to T cells for 48 hours fllowed by the addition of SATM and IL-2; SATM inhibited3HTdR incorporation even though receptor expression had occurred. These results suggest that SATM inhibits the stimulatory effects of IL-2 on T cells partly by interfering with IL-2 receptor expression, and partly by other mechanisms of action. These effects of SATM may explain some of the conflicting data in the literature on T cell responses to IL-2 in rheumatoid arthritis (RA), and suggest a possible mechanism of action for the drug in the treatment of RA.

ISSN:0892-3973    

DOI:10.3109/08923978809014329

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThe in vitro effects of lentinan on natural killer (NK), antibody-dependent cell-mediated cytotoxicity (ADCC), lectin-dependent cell-mediated cytotoxicity (LDCC) and mitogen-induced blast transformation were studied in patients with solid tumors and chroyic lymphocytic leukemia (CLL). NK activity was measured against Cr-labelled K-562 targets, ADCC against antibody-coated chicken red cells. LDCC and natural cell-mediated cytotoxicity (NCMC) was assessed using3H-thymidine prelabelled HEp-2 targets. Mitogen (PHA-and Con A-) induced blast transformation was measured by thymidine incorporation.Blastogenesis and LDCC was not influenced by lentinan. 1μg/ml lentinan increased NCMC of tumor-bearing subjects. The most prominent enhancement of NK and ADCC activity was seen in CLL patients, where a dose-related increase was seen (from 0.01 to 1μg/ml).

ISSN:0892-3973    

DOI:10.3109/08923978809014330

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractDesferrioxamine (DFO), an iron chelating drug, has been shown to inhibit the proliferative response of leukocytes to mitogen. In the present study we investigated the effect of DFO on different aspects of human mononuclear leukocyte (MNL) function in vitro. DFO, added at the beginning of the culture period, inhibited both tritiated thymidine and radioiron uptake by phytohemagglu tinin-stimulated MNL and the degree of inhibition correlated with the degree of cellular activation, to the extent that in the absence of mitogen a significant stimulatory effect of DFO was observed, especially when iron supplement was present in the culture medium. However DFO was not found to inhibit iron uptake directly, and relatively low concentrations of iron as iron-transferrin totally reversed the inhibitory action of DFO on thymidine uptake. Although the release of iron from preloaded MNL in the presence of DFO was only 15% greater than the spontaneous release of control cultures, we conclude that the site of action of DFO is an intracellular iron pool, that increases in importance when the supply of iron to the cellular iron metabolism become limiting as in optimally activated MNL.

ISSN:0892-3973    

DOI:10.3109/08923978809014331

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractPregnant C3H/Anfcum mice were injected ip with 150 ug benzo-(a)pyrene (BP)/g body weight at the second trimester (12 days). Quantitative and differential changes were assayed in the peripheral blood leukocytes and erythrocytes at various times before and after mating and treatment. Within 5 days after injection, a 2- to 4-fold reduction in leukocytes was observed when compared to controls [corn oil (vehicle for BP)-injected pregnant females] which persisted into the 10th postpartum day. The erythrocytes were also significantly reduced but not to the same degree (1.2- to 1.5-fold). Depression in white blood cells is attributed to lymphocyte depletion since the granulocytes were virtually unchanged and the lymphocyte to granulocyte ratio, ordinarily>2 was 1 or

ISSN:0892-3973    

DOI:10.3109/08923978809014332

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractProgeny from benzo(a)pyrene (BP) mposed (150 ug/g body weight) primiparous mothers, injected during the second trimester of pregnancy, are severely compromised immunologically. In view of maternal-fetal associations, we studied, during pregnancy and postpartum, the quantitative and functional status of the maternal T cell population in the thymus and/or spleen. In the thymus, there is an exacerbated depression in the amounts of thymocytes, (tH+, Lyt 1+, Lyt 2+cells) during pregnancy relative to the corn oil-injected controls, which is sustained postpartum. In the spleen, while there are inconsistencies in the level ofθ+cells, The Lyt 1+are depressed postpartum relative to virgins, but the Lyt 2+are enhanced during pregnancy and postpartum, reaching levels<700-fold of controls. In controls, while the number of Lyt 1+cells was higher than BP-exposed mice or virgins during pregnancy, they virtually disappeared postpartum. A similar but reversed image is mirrored by the Lyt 2+cells, i.e., they were virtually absent during pregnancy but increased postpartum. Splenic allogeneic and syngeneic mixed lymphocyte responses were subnormal. The data show that BP disrupts the maternal T cell repertoire, leading to an accumulation of Lyt 1--2+cells, and suggest that splenic disruption may be due to changes in the differentiation potential of T precursor cells. These changes not only are most likely to affect maternal defenses, but also may have a direct bearing on the establishment of progeny immune status.

ISSN:0892-3973    

DOI:10.3109/08923978809014333

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractThe induction of T-cell responses involves the recognition of extrinsic antigens in association with antigens of the major histocompatibility complex (MHC). The present results demonstrate that the lateralized control exerted by the brain neocortex on T-cell activities extends to the expression of MHC antigens, yet differently on spleen or lymph node T cells. This study also shows that the neocortex influences the changes induced by an immunopotentiator, sodium diethyldithiocarbamate Cirnuthiol), on the MHC antigen content on mouse T cell- surface.

ISSN:0892-3973    

DOI:10.3109/08923978809014334

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor

摘要:

AbstractCoxiella burnetii, the etiological agent of Q fever, possesses immunomodulatory activity which positively and negatively regulates host immune responses. We wish to determine theCoxiellastrain differences and the chemical nature of cellular components suppressing lymphocyte responsiveness. The bacterial components responsible for the immunomodulatory activity are associated with phase I cells. In its natural state, the phase I cell-associated, immunosuppressive complex (ISC) was resistant to chemical and enzymatic treatment. The TSC was inactivated and rendered accessible by chloroform-methanol (CM) (4:1) extraction of phase I cells which produced a CM residue (CMRI) and CM extract (CME). The suppressive components in either CMRI or CME did not induce TSC activity in the host when injected separately. Reconstitution of the CMRI with CME prior to injection produced the same pathological reactions characteristic of phase I cells. The CMRI suppressive component was sensitive to alkali, acid, periodate, lysozyme, and neuraminidase, but resistant to lipase and protease. An active component of CMRI was attached to the cell matrix by disulphide bonds. The amphipathic, Lipophilic, CME suppressive component was ubiquitously distributed in procaryotes and eukaryotes because ISC activity of CMRI was regained after association with reagent-grade lipids and different CMEs. The ISC was expressed by phase I strains with smooth lipopolysaccharide (LPS) but not by phase II strains with rough LPS. Phase I heart valve strains carrying significant amounts of rough LPS did not express all of the biological properties of the ISC. The LPS molecule induced immune enhancement without immunosuppression. Thus, expression of the ISC showed strain variation and may be under genetic control. The complete details of the chemical composition and active components of the ISC shoultl prove useful for biological-response-modification studies.

ISSN:0892-3973    

DOI:10.3109/08923978809014335

出版商:Taylor&Francis    

年代:1988

数据来源: Taylor