Generation Of Suppressor Macrophages Research Articles

Glucocorticoid-mediated generation of suppressor macrophages with high density Fc gamma RII during acute cold stress

Glucocorticoid-mediated generation of suppressor macrophages with high density Fc gamma RII during acute cold stress

Preventive effect of a synthetic immunomodulator, 2-carboxyethylgermanium sesquioxide, on the generation of suppressor macrophages in mice immunized with allogeneic lymphocytes.

The effect of 2-carboxyethylgermanium sesquioxide (Ge-132) on the generation of splenic suppressor macrophages (S-M phi) in C3H/He mice (H-2k) immunized with allogeneic spleen cells from C57Bl/6 mice (H-2b) was investigated. We have previously demonstrated that S-M phi expressing I-J antigen, which appeared during alloimmunization, inhibited cytotoxic T lymphocyte (CTL) generation in the MLR and the elimination of these S-M phi before subjection to the MLR resulted in more effective generation of CTL. The CTL activity, which was determined in vivo by the Winn's test, was markedly enhanced when immunized mice received a 100 mg/kg dose of Ge-132. The compound was found to be the most efficacious when injected simultaneously with the immunization. The activity of allospecific CTL co-cultured with M phi fractions obtained from immunized mice in a 4-h 51Cr-release assay was shown to be 31% lysis of the target cells as compared with 90% lysis of the target cells in effector cells co-cultured with normal M phi fractions. In contrast, effector cells co-cultured with M phi fractions from Ge-132-treated immunized mice lysed 95% of the target cells. Analysis of the level of I-J antigen expression on macrophages (M phi) obtained from mice 7 days after immunization revealed a > 2.5-fold increase, whereas I-A antigen expression remained constant when compared with splenic M phi from naive mice. In contrast, the opposite effect on I-J and I-A antigen expression was observed in splenic M phi from alloimmunized mice treated with Ge-132. These results suggest that Ge-132 could regulate CTL generation in alloimmunized mice by preventing the generation of I-J+ S-M phi.

Possible mechanism of the preventive effect of BCG against diabetes mellitus in NOD mouse: I. Generation of suppressor macrophages in spleen cells of BCG-vaccinated mice

With the aim of clarifying the mechanism of the suppressive action of BCG against insulitis and overt diabetes in NOD mice, we studied the effects of BCG on spleen cell populations and on the in vitro immune responses of spleen cells. The spleen cells of BCG-vaccinated mice showed much lower responsiveness to various mitogens such as Con A, PHA, PWM, and LPS than those of saline-treated mice. Low responsiveness to alloantigens was also observed. Flow cytometric analysis of the spleen cells revealed that Mac-1 + and Mac-2 + cells had increased while T and B cells had decreased in the BCG-vaccinated mice compared with the saline-treated mice at the time when the maximum level of inhibition of mitogen responses of BCG-vaccinated mice was observed. This suggests that the decreased in vitro immune response was due to the increase in macrophages which suppress lymphocyte functions. Support for this interpretation comes from the following two findings: (1) the restoration of mitogen responses of spleen cells when macrophages were eliminated by plastic adhesion or FACS sorting and (2) resuppression of PHA and Con A responses of plastic-nonadherent spleen cells by addition of adherent cells or flow cytometrically sorted Mac-1 + cells obtained from BCG-vaccinated mice. These results indicate the generation of suppressor macrophages after BCG vaccination and suggest that these macrophages prevent the autoimmune pathogenesis leading to diabetes in NOD mice.

Suppressor cell regulation of encephalitogenic T cell lines: Generation of suppressor macrophages with cyclosporin A and myelin basic protein

Chronic relapsing experimental allergic encephalomyelitis (CR-EAE) can be adoptively transferred using myelin basic protein (BP)-specific helper T cell lines, and suppressor cells may be important in recovery from EAE. In order to generate suppressor cells, spleen cells obtained from BP-complete Freund's adjuvant (CFA) inoculated SJL/J mice and from normal mice were cultured for 7 days with medium, with cyclosporin A (CsA), or with CsA and antigen (BP or purified protein derivative of mycobacterium (PPD)). Cultured spleen cells were assayed for suppressor activity in vitro by coculture with BP-specific and PPD-specific helper T cell lines derived from SJL/J mice. Immunized donor spleen cells cultured with cyclosporin A (CsA) and BP were potent inhibitors of T cell line proliferation, and suppressor activity was increased 17-fold compared with control splenocytes. The number of suppressor cells required to suppress PPD-specific line proliferation by 50% ( I 50) was significantly higher than the number required to suppress BP-specific line proliferation, suggesting an antigen-specific component to the suppression. The major effector cell required for suppression was a large granular Mac-1 + cell with the functional characteristics of a macrophage. Suppressor activity persisted after depletion of Thy 1.2+ cells, but suppression was no longer antigen-specific, suggesting that culture of spleen cells with CsA and BP may generate suppressor macrophages which are antigen-nonspecific and Thy 1.2+ suppressor cells which are antigen-specific. These suppressor cells may be important in the regulation of CR-EAE and the techniques described for their generation may prove useful for treatment and prevention of disease.

Suppressor Lyt 2+ T-cells demonstrated in mice late after thermal injury

Biological properties of suppressor cells mediating second suppressive state (S-SupS) of IFN-gamma responsiveness in mice following thermal injury were investigated by their ability to inhibit [3H]thymidine incorporation by allogeneic cell-stimulated mononuclear cells (MNC) prepared from spleens of unburned normal mice (N-mice). Kinetic studies indicated that the suppressor cells appeared at approximately 15 days post-burn and persisted until 40 days after thermal injury. This cell population from the spleens of thermally injured mice (TI-mice) was inactivated by anti-Thy 1.2 monoclonal antibody (mAb) plus complement (C). Treatment with antimouse immunoglobulin and anti-Lyt 1.2 mAb followed by C failed to abrogate the activity. However, it could be eliminated by treatment with anti-Lyt 2.2 mAb and C. In addition, when Thy 1+ or Lyt 2+ T cells were depleted from spleen cells containing suppressor cell activities by treatment with mAbs and C, the suppressor activity for IFN-gamma production by N-mice splenic MNC stimulated with concanavalin A was also eliminated. However, no alteration in the suppression of IFN production was observed when this splenic cell population from TI-mice was treated with anti-Lyt 1.2 mAb and anti-mouse Ig followed by C. Since it has been reported [1] that the suppressor cell in spleens of TI-mice could neither be removed by plastic adherence nor by carbonyl-iron treatment, this secondarily-generated suppressor cell was concluded to be a T cell possessing the Lyt 1-2+ phenotype. The present report describes the demonstration, following a generation of suppressor macrophages [2], of suppressor Lyt 2+ T cells spleen of mice late after thermal injury.

Prevention of suppressed interferon gamma production in thermally injured mice by administration of a novel organogermanium compound, Ge-132.

As reported previously, gamma interferon (IFN-gamma) production was selectively decreased in thermally injured mice (TI-Mice) and spleen cell cultures from the mice following stimulation with various IFN inducers. The decrease in IFN production was associated with splenic suppressor macrophages. The present study demonstrated that TI-Mice treated with Ge-132 (TGe-Mice) produced IFN following stimulation with IFN-gamma inducers. The level of IFN activity detected in the sera of TGe-Mice approximated that of controls. Similar results were obtained when spleen cells prepared from TGe-Mice were stimulated with IFN-gamma inducers in vitro. While transfer of spleen cells from TI-Mice resulted in the suppression of IFN production in normal mice (N-Mice) stimulated with IFN-gamma inducers, the transfer of spleen cells derived from TGe-Mice did not induce suppression of IFN production in N-Mice. Mononuclear cells (MNC) prepared from N-Mice produced IFN following concanavalin A (Con A) stimulation when they were co-cultured with macrophage-enriched populations (PAC) obtained from the spleens of TGe-Mice. In contrast, MNC stimulated with Con A did not produce IFN activity when they were co-cultured with PAC of TI-Mice. These results suggest that the generation of suppressor macrophages in TI-Mice may be altered by the administration of Ge-132.