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V Umansky

Publications and source records attributed to V Umansky.

51 records · Page 3Linked to original sources
PubMed1998

Antagonistic effects of systemic interleukin 2 on immune Tcell-mediated graft-versus-leukemia reactivity.

This study demonstrates that systemic interleukin 2 (IL-2) can decrease the homing of syngeneic immune T cells to the target organ of metastases and accelerate unwanted side effects of allogeneic immune T cells. As a tumor system, we used the well-characterized highly aggressive DBA/2 mouse leukemia ESb and its less aggressive adhesion variant, ESb-MP. Systemic IL-2 treatment was performed with recombinant human interleukin-2 (Proleukin), which was slowly released via an implanted osmotic pump or was modified with polyethylene glycol (PEG-IL-2) to achieve constant plasma levels. Allogeneic B10.D2 antitumor immune spleen cells (ISPL cells) exerted strong graft-versus-leukemia (GvL) reactivity after adoptive transfer into late-stage ESb-MP tumor-bearing DBA/2 mice. Mls(a) superantigen-reactive vbeta6 donor T cells were not eliminated or tolerized by in vivo priming with the tumor cells and were present in active proliferation in liver infiltrates. When exogenous PEG-IL-2 or Proleukin was applied in addition to ISPL cells in such mice, the strong GvL-mediated protective immunity was converted into a fatal graft-versus-host disease. IL-2 treatment alone had no toxic effect and caused a moderate protection effect in the absence of an effect on local tumor growth. Potentiation of GvH reactivity of B10.D2 ISPL by PEG-IL-2 was proven in non-tumor-bearing DBA/2 mice, in which graft-versus-host disease was characterized by: (a) heavy hepatic lymphocytic infiltration, (b) irreversible increase of serum glutamate-oxalacetate-transaminase and glutamate-pyruvate-transaminase levels, (c) weight loss, and (d) death. Antagonistic effects of systemic IL-2 on GvL were observed with syngeneic DBA/2 anti-ESb immune peritoneal effector cells (PECs). There was a detrimental effect of systemic IL-2 on liver target organ infiltration by immune T cells causing, at day 6 after transfer, a drop from 20-30 CD4 or CD8 T cells per liver lobule in the PEC group to <5 in the PEC plus IL-2 group. The results emphasize the importance of a better understanding of IL-2 function in vivo and of its interaction with immune cell function to improve protocols for optimal application in the clinic to achieve maximal GvL effects.

Animals↗
PubMed1998

Graft-versus-leukemia reactivity involves cluster formation between superantigen-reactive donor T lymphocytes and host macrophages.

T-cell-mediated antitumor effects play an important role clinically in allogeneic graft-versus-leukemia (GvL) reactivity, whereas T-cell-mediated antihost effects are associated with a risk of developing graft-versus-host (GvH) disease. GvL and GvH were compared in an animal tumor model system after the systemic transfer of allogeneic antitumor immune T lymphocytes from B10.D2 [H-2d; minor lymphocyte-stimulating antigen (Mls)b] mice into ESb-MP tumor-bearing or normal DBA/2 (H-2d; Mls(a)) mice. Here we demonstrate that this T-cell-mediated therapy involves the formation of clusters of donor CD4 and CD8 T cells with host macrophages, in particular, with a subpopulation expressing the lymphocyte adhesion molecule sialoadhesin. DBA/2 mice and the derived tumor ESb-MP express viral superantigen 7 (Mls(a)), an endogenous viral superantigen that is absent from B10.D2 mice. To test the contribution of viral superantigen 7-reactive Vbeta6 donor T cells in the GvL-mediated eradication of liver metastases, we performed immunohistological and transmission electron microscopy studies. Vbeta6+ CD4 and CD8 T cells from B10.D2 donors formed tight clusters with host sialoadhesin-positive macrophages, and transmission electron microscopy pictures revealed direct membrane-membrane interactions between T cells and macrophages. Clusters were more abundant and consisted of more cells in tumor-bearing hosts (GvL model) than in non-tumor-bearing hosts (GvH model). In addition, Vbeta6 T cells within the clusters showed a strong proliferation activity, indicating stimulation. Moreover, in an in vitro tumor cytostasis assay, primed as well as nonprimed purified Vbeta6 T cells from donor mice were able to inhibit the proliferation of superantigen-expressing ESb-MP lymphoma cells. This suggests that the transferred superantigen-reactive Vbeta6 T cells contribute to the eradication of metastases. The observed cell clusters might be sites for antigen presentation and the activation of tumor-reactive T cells.

Animals↗
PubMed1997

Differences between graft-versus-leukemia and graft-versus-host reactivity. I. Interaction of donor immune T cells with tumor and/or host cells.

Graft-versus-leukemia (GVL) and Graft-versus-host (GVH) reactions were compared after systemic transfer of allogeneic antitumor immune T lymphocytes from B10.D2 (H-2d; Mls(b)) into DBA/2 (H-2d; Mis(a)) mice. Before immune cell transfer, recipient DBA/2 mice were sublethally irradiated with 5 Gy to prevent host-versus-graft reactivity. Recipients were either bearing syngeneic metastatic ESb lymphomas (GVL system) or were normal, non-tumor-bearing mice (GVH system). We previously reported that this adoptive immunotherapy protocol (ADI) had pronounced GVL activity and led to immune rejection of even advanced metastasized cancer. In this study, monoclonal antibodies were used for immunohistochemical analysis of native frozen tissue sections from either spleen or liver to distinguish donor from host cells, to differentiate between CD4 and CD8 T lymphocytes, and to stain sialoadhesin-positive macrophages at different time points after cell transfer. The kinetics of donor cell infiltration in spleen and liver differed in that the lymphoid organ was infiltrated earlier (days 1 to 5 after transfer) than the nonlymphoid organ (days 5 to 20). After reaching a peak, donor cell infiltration decreased gradually and was not detectable in the spleen after day 20 and in the liver after day 30. The organ-infiltrating donor immune cells were mostly T lymphocytes and stained positive for CD4 or CD8 T-cell markers. A remarkable GVL-associated observation was made with regard to a subset of macrophages bearing the adhesion molecule sialoadhesin (SER+ macrophages). In the livers of tumor-bearing mice, their numbers increased between days 1 and 12 after ADI by a factor greater than 30. Double-staining for donor cell marker and SER showed that the sialoadhesin-expressing macrophages were of host origin. The SER+ host macrophages from GVL livers were isolated by enzyme perfusion and rosetting 12 days after ADI, when they reached peak values of about 60 cells per liver lobule, and were tested, without further antigen addition, for their capacity to stimulate an antitumor CD8 T-cell response. The results of this immunologic analysis suggest that these cells in the liver function as scavengers of the destroyed metastases and as antigen-processing and -presenting cells for antitumor immune T cells.

Animals↗
PubMed1996

New insights into tumor-host interactions in lymphoma metastasis.

The metastatic process is characterized by a complex series of sequential steps involving constant interactions (mutual "cross-talks") of metastasized tumor cells with their microenvironment (lymphocyte, macrophages, endothelial cells, etc.) in target organs. These interactions determine the outcome of metastasis (either the eradication of metastatic cells or their increased proliferation and invasion). Recently developed methods of tumor and host cell analysis at the molecular level allow better elucidation of molecular mechanisms of metastasis and of immune mechanisms involved in antitumor responses. Direct modulation of these processes will probably increase the success of clinical cancer treatment. Here we review data (a) on the expression of some costimulatory (MHC class II, CD80, sialoadhesin) and adhesion (LFA-1, ICAM-1, VLA-4) molecules on both metastasized tumor cells and host cells and (b) on the production of a cytotoxic molecule, nitric oxide, by in situ activated Kupffer and endothelial cells in the process of liver metastasis. This study was performed with well-characterized murine ESbL T lymphoma cells transduced with the bacterial lacZ gene, which allows detection and quantification of metastases at the single cell level throughout lymphoma growth and metastasis. Experimental results are discussed in the context of recent literature.

Cell Adhesion Molecules↗
PubMed1996

Liver endothelial cells: participation in host response to lymphoma metastasis.

Interactions between metastasizing tumor cells and host cells in target organs determine the outcome of metastasis. This review discusses the dual role of activated host endothelial cells in the metastatic process. On one hand, the upregulation of the expression of particular adhesion molecules leads to increased tumor cell binding, and the stimulation of angiogenesis provides the vascular support for the growth of already established metastases. On the other hand, endothelial cells can contribute to host anti-metastatic responses, e.g. by production of the cytotoxic molecule nitric oxide (NO) from arginine with the help of the inducible nitric oxide synthase (iNOS). Using a well-characterized ESbL-lacZ mouse T lymphoma model with a typical three phasic growth profile, we showed during the period of growth retardation a stimulation of NO production by ex vivo isolated liver sinusoidal endothelial cells. The induction of NO synthesis in liver endothelial cells did not require the presence of Kupffer cells and appeared to be stimulated by and dependent on mature T lymphocytes. A breakdown of this NO synthesis coincided with the second tumor expansion phase.

Animals↗
PubMed1996

Dissection of tumour and host cells from target organs of metastasis for testing gene expression directly ex vivo.

We report on a new methodology which allows the direct analysis ex vivo of tumour cells and host cells (lymphocytes, macrophages, endothelial cells) from a metastasised organ (liver or spleen) at any time point during the metastatic process and without any further in vitro culture. First, we used a tumour cell line transduced with the bacterial gene lacZ, which permits the detection of the procaryotic enzyme beta-galactosidase in eukaryotic cells at the single cell level thus allowing flow adhesion cell sorting (FACS) analysis of tumour cells from metastasised target organs. Second, we established a method for the separation and enrichment of tumour and host cells from target organs of metastasis with a high viability and reproducibility. As exemplified with the murine lymphoma ESb, this new methodology permits the study of molecules of importance for metastasis or anti-tumour immunity (adhesion, costimulatory and cytotoxic molecules, cytokines, etc.) at the RNA or protein level in tumour and host cells during the whole process of metastasis. This novel approach may open new possibilities of developing strategies for intervention in tumour progression, since it allows the determination of the optimal window in time for successful treatments. The possibility of direct analysis of tumour and host cell properties also provides a new method for the evaluation of the effects of immunisation with tumour vaccines or of gene therapy.

Animals↗
PubMed1996

Induction of NO synthesis in macrophages by Newcastle disease virus is associated with activation of nuclear factor-kappa B.

Newcastle disease virus (NDV) has received much attention recently because of its non-specific immune stimulating potential and its various anti-tumor activities. Here we describe that NDV induces synthesis of NO and causes an activation of nuclear factor-kappa B (NF-kappa B) in murine macrophages. These reactions were part of an activation process which included also stimulation of adenosine deaminase and inhibition of 5'-nucleotidase. NDV-mediated NO synthesis and NF-kappa B activation were blocked by an antioxidant (butylated hydroxyanisole), by an inhibitor of protein tyrosine kinase (genistein) and of protein kinase A (H-89), but not by an inhibitor of protein kinase C (staurosporin). These data suggest that signalling requirements of NF-kappa B activation and NO production in NDV-treated macrophages are similar.

Adenosine Deaminase↗
PubMed1996

A role for sialoadhesin-positive tissue macrophages in host resistance to lymphoma metastasis in vivo.

Sialoadhesin (SER) is a newly described macrophage-restricted adhesion molecule with a sequence similarity to CD22 on B cells and to myelin-associated glycoprotein on Schwann cells. We describe here a functional role of SER+ spleen macrophages in antigen processing and presentation to T lymphocytes. In two syngeneic murine tumour systems (ESb-MP and lacZ transduced ESbL T-lymphoma cells), the activation state of SER+ macrophages (tested by activity of marker enzymes adenosine deaminase and 5'-nucleotidase) correlated with the arrest of lymphoma metastasis. Furthermore, this macrophage subpopulation became activated upon anti-tumour immunization as well as upon adoptive transfer of immune T lymphocytes into tumour-bearing hosts. We suggest that in situ-activated SER+ macrophages contribute to host resistance against metastasis.

Animals↗
PubMed1996

Dynamic expression changes in vivo of adhesion and costimulatory molecules determine load and pattern of lymphoma liver metastasis.

Although intradermal primary tumor growth and spontaneous liver metastasis of ESbL-lacZ lymphoma in syngeneic DBA/2 mice are progressive and malignant, they are characterized by a transient plateau period with a constant tumor diameter and a low number of metastasized cells in the liver. This period, which was shown to be immune dependent, was followed by a second expansion phase characterized by a preferential localization of tumor cells in the periportal areas of liver lobules (mosaic phenotype). To elucidate possible mechanisms leading to the plateau period as well as for the mosaic-like metastasis pattern, we investigated, using flow cytometry analysis, alterations in costimulatory and adhesion molecule expression in liver sinusoidal cells as well as in tumor cells isolated directly ex vivo throughout the kinetics of metastasis. In tumor and sinusoidal cells, we found up-regulation in the expression of MHC class II and B7 molecules during the plateau period. These molecules, which facilitate cell-mediated immune responses, were again down-regulated during the final exponential tumor growth and metastasis. In the final expansion phase, in which the mosaic phenotype of liver metastasis is seen, we detected a significant increase of leukocyte function-associated antigen-1/intercellular adhesion molecule-1 expression in both tumor and sinusoidal cells, suggesting tumor cell-sinusoidal cell interactions. vascular cell adhesion molecule-1/very late activated antigen-4 did not show any modification during the whole metastatic process. In vivo application of monoclonal antibodies directed to leukocyte function-associated antigen-1 and intercellular adhesion molecule-1 appeared to block the spread of metastasis, while no effect was seen with monoclonal antibodies directed to vascular cell adhesion molecule-1 and very late activated antigen-4. This study reveals in situ expression changes of cell surface molecules in tumor and host cells during metastasis. The changes seen during the plateau phase and during the second expansion phase differ, suggesting associations with mechanisms of immune control and tumor immune evasion, respectively.

Animals↗
PubMed1995

Liver endothelial cells participate in T-cell-dependent host resistance to lymphoma metastasis by production of nitric oxide in vivo.

Tumor growth and metastasis of lacZ-transduced murine lymphoma ESbL cells inoculated into syngeneic DBA/2 mice are characterized by a transient plateau phase with a constant tumor diameter and low metastatic load, indicating a host response against the tumor. Here we show that endothelial cells participate in a T-cell-dependent, anti-metastatic response by producing NO in situ. Liver endothelial cells were isolated and examined directly ex vivo without further manipulation. NO production in liver endothelial cells reached the highest level during the plateau phase but declined toward the end of it, followed by an overall breakdown of host response, leading to progressive tumor growth and high load of liver metastasis. Mice subjected to anti-tumor immunization and subsequent challenge with a tumorigenic dose of ESbL-lacZ cells showed, in comparison to non-immunized challenged controls, reduced liver metastasis and increased endothelial NO production. Adoptive transfer of anti-tumor immune spleen cells from semi-allogeneic B10.D2 mice into tumor-bearing animals during the plateau phase caused a regression of primary tumor and metastases, together with a preservation of the high level of NO synthesis in endothelial cells. In immuno-incompetent (SCID) mice, tumor growth and metastasis were progressive and there was no endothelial NO response. Pre-immunization of immuno-competent mice with both live and irradiated tumor cells at different sites of the body led to an induction of NO production by liver endothelial cells. These results reveal a novel role of endothelial cells in the suppression of lymphoma metastasis in the liver. The inducible endothelial cell NO response is apparently dependent and induced by mature T lymphocytes.

Animals↗
PubMed1994

Pattern and load of spontaneous liver metastasis dependent on host immune status studied with a lacZ transduced lymphoma.

Detection of disseminated leukemia within organ is often very difficult and might lead to underestimation of the metastatic load. Therefore, we transduced the mouse ESb T lymphoma with the bacterial lacZ gene, which allowed us to follow metastasis at the single cell level. Intradermal primary tumor growth of lacZ transduced ESbL cells (L-CI.5s) comprised three phases: an initial expansion phase (day 0 to 9, increase from 0 to 8 mm, tumor diameter), a plateau phase (day 9 to 20, constant diameter of 8 mm and necrosis), and a second expansion phase (day 20 to 30, increase from 8 to 15 mm). Liver metastasis could already be detected at day 3 and maintained at that level until day 23, where exponential expansion started. A distinct mosaic-like metastasis pattern developed, with preferential localization of tumor cells to the periportal areas of the liver in immunocompetent animals. In contrast, in immunocompromised mice, primary tumor growth and metastasis were progressive and metastasis appeared as diffuse or focal/clustered. Healthy animals surviving a tumor cell inoculum of a variant cell ESbL-CI.5) with a reduced metastatic potential carried low levels of possibly dormant tumor cells in the bone marrow. Thus, this study showed that host immunocompetence determines to a large extent kinetics and load of spontaneous liver metastases and even influences the pattern and localization of disseminated lymphoma cells.

Animals↗