scholarly journals Treatment of Graft-versus-Host Disease by Echinomycin in a New Humanized Mouse Model

2017 ◽  
Author(s):  
Yan Liu ◽  
Christopher Bailey ◽  
Christopher Lazarski ◽  
Chun-shu Wong ◽  
Pan Zheng ◽  
...  

AbstractDrug development effort against GVHD is hampered by the lack of clinically relevant humanized animal models for preclinical testing. Current humanized GVHD models rely on adoptive transfer of a high number of human peripheral blood mononuclear cells (PBMCs) into immunodeficient mice. Here we report a novel humanized GVHD model by transplanting a small number of human BM cells into newborn NOD. SCID IL2ry0 (NSG) mice. Transplantation of human BM cells (BMT) causes acute GVHD, with lethality between 15 to 60 days. Pervasive human T-cell infiltration into multiple organs, including lung, intestine, skin, kidney, liver, and stomach, was observed in all mice analyzed. Surprisingly, the human T cells express high levels of hypoxia inducible factor 1α (HIF1α) protein even under normoxic environment. Administration of Echinomycin, a potent inhibitor for HIF1α, rapidly ablated HIF1α protein in T cells and gradually reduced the frequency of human cells in the peripheral blood and target organs. Echinomycin provides a sustained therapeutic effect, as demonstrated by dramatic reduction of clinical symptoms, pathology score and by doubling of the median life span of the chimeric mice. Our results reveal a critical role of HIF1α in GVHD and demonstrate that HIF1α inhibitors such as Echinomycin should be explored for clinical drug development against GVHD.

1992 ◽  
Vol 175 (2) ◽  
pp. 503-516 ◽  
Author(s):  
M Tary-Lehmann ◽  
A Saxon

In these studies we have characterized the human cells that repopulate severe combined immunodeficient (SCID) mice after injection of adult peripheral blood or cord blood (hu-PBL-SCID mice). In all organs of the chimeras, and at any time point tested, single-positive (CD4+ or CD8+) T cells that expressed the alpha/beta T cell receptor (TCR) prevailed. All T cells were CD45RO+ and the majority were also HLA-DR+. Thus, the human T cells in the chimeras exhibited the phenotype of mature, memory cells that showed signs of recent activation. Cell cycle studies revealed a mitotically active human T cell population in the murine host. However, when freshly isolated from the chimeras, the human T cells were refractory to stimulation by anti-CD3 antibody but proliferated in response to exogenous interleukin 2. Chimera-derived human T cell lines retained this state of unresponsiveness to TCR-triggered proliferation for 4-6 wk in vitro. Subsequently, the T cell lines developed responses to anti-CD3 stimulation and 9 of 11 of the lines also proliferated in response to splenic stimulator cells of SCID mice. These data demonstrate that the human T cells are in a state of reversible anergy in the murine host and that xenoreactivity might play a critical role in hu-PBL-SCID mice. Mechanisms that may determine repopulation of SCID mice with human peripheral blood mononuclear cells are discussed.


1994 ◽  
Vol 179 (1) ◽  
pp. 311-315 ◽  
Author(s):  
M K Perera ◽  
R Carter ◽  
R Goonewardene ◽  
K N Mendis

The percentage of peripheral blood mononuclear cells (PBMC) bearing the CD3+ phenotype and the alpha/beta and gamma/delta T cell receptors (TCR) in PBMC were examined in Plasmodium vivax malaria patients and convalescents. The cells were labeled with monoclonal antibodies, stained with either fluorescence or phycoerythrin, and examined by ultraviolet (UV) microscopy. A highly significant increase in both the proportion and the absolute numbers of gamma/delta T cells (p < 0.005 and < 0.001, respectively, Student's t test) was observed in nonimmune P. vivax patients during clinical paroxysms compared to nonmalarial controls. These T cells, which normally constitute not more than 3-5% of PBMC, constituted < or = to 30% of PBMC during paroxysms in these nonimmune patients in whom the clinical symptoms were severe. A less significant increase of gamma/delta T cells were also observed in these nonimmune patients during infection, between paroxysms and during convalescence. In contrast, in an age-matched group of semi-immune patients resident in a malaria-endemic region of the country, in whom the clinical disease was comparatively mild, there was no increase in gamma/delta T cells either during infection, even during paroxysms, or convalescence. The severity of disease symptoms in patients as measured by a clinical score correlated positively with the proportion of gamma/delta T cells in peripheral blood (r = 0.53, p < 0.01), the most significant correlation being found between the prevalence and severity of gastrointestinal symptoms, nausea, anorexia, and vomiting, and the proportion of gamma/delta T cells (r = 0.49, p = 0.002). These findings suggest that gamma/delta T cells have a role to play in the pathogenesis of malaria, possibly in the general constitutional disturbances and particularly in gastrointestinal pathology in malaria.


Blood ◽  
1989 ◽  
Vol 74 (4) ◽  
pp. 1348-1354 ◽  
Author(s):  
HG Klingemann ◽  
S Dedhar

Abstract The receptors for fibronectin (FN-R) and vitronectin (VN-R) belong to a family of integral membrane glycoproteins known to be involved in cell- extracellular matrix and cell-cell interactions named integrins (FN-R = beta 1 integrin and VN-R = beta 3 integrin). Adhesion studies using FN- coated plastic dishes and highly purified subpopulations of peripheral blood mononuclear cells (PBMCs) showed a strong binding of monocytes and T lymphocytes to FN but virtually no binding of B cells to FN. Binding of monocytes and T cells to FN could be partially inhibited by a hexapeptide (GRGDSP) containing the adhesive peptide sequence Arg-Gly- Asp (RGD) as well as by an anti-FN-R antibody. The distribution of beta 1 and beta 3 integrin complexes on PBMCs was characterized by immunoprecipitation of detergent extracts of 125I-labeled cells using polyclonal antibodies against these two receptors. Two surface polypeptides corresponding to the alpha and beta chains of FN-R and VN- R were found on all three cell types. To characterize these receptors further, monoclonal antibodies (MoAbs) against the very late antigens (VLAs) 1, 3, and 5 were used for immunoprecipitation studies. Monocytes and T cells reacted with VLA 5 that was previously identified as the human FN receptor, whereas no labeling with anti-VLA 5 could be shown for B cells. When cell populations were cultured in 10% human serum for 24 hours, an increase in beta 1-integrin+ monocytes and T cells was observed. The number of beta 3-integrin+ cells remained essentially unchanged. The presence of beta 1 and beta 3 integrins on monocytes as well as on T and B lymphocytes may be of significance in the ability of these cells to interact with each other and participate in hematopoiesis and certain immune reactions.


Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 89-100 ◽  
Author(s):  
SR Goan ◽  
I Fichtner ◽  
U Just ◽  
L Karawajew ◽  
W Schultze ◽  
...  

Mononuclear cells (MNCs) containing peripheral blood stem cells (PBSCs) were obtained from solid-tumor patients undergoing mobilizing chemotherapy followed by granulocyte colony-stimulating factor for PBSC transplantation-supported dose-intensified anticancer chemotherapy and were transplanted into unconditioned “nonleaky” young severe combined immunodeficient mice. Multilineage engraftment was shown by flow cytometry and immunocytochemistry using monoclonal antibodies to various human cell surface antigens as well as identification of human immunoglobulin in murine sera. Within a dose range of MNCs suitable for transplantation (10 to 36 x 10(6) cells/graft) the number of CD34+ cells injected (optimal at > 0.7 x 10(6)/graft) determined the yield of human cells produced in recipient animals. Engraftment of hu PBSC preparations resulted in prolonged generation of physiologic levels of human cytokines including interleukin-3 (IL-3), IL-6, and granulocyte- macrophage colony-stimulating factor, which were detectable in the murine blood over a period of at least 4 months. In vivo survival of immature human progenitor cells was preserved even 9 months after transplantation. Because human IL-3 is known to stimulate early hematopoiesis, a rat fibroblast cell line was stably transfected with a retroviral vector carrying the human IL-3 gene and cotransplanted subcutaneously as additional source of growth factor. Cotransplants of this cell line producing sustained in vivo levels of circulating human IL-3 for at least 12 weeks significantly accelerated the process of engraftment of huPBSC and spurred the spread of mature human cells to the murine spleen, liver, thymus, and peripheral blood. Cotransplants of allogeneic human bone marrow stromal cells derived from long-term cultures resulted in a comparable--though less prominent--support of engraftment.


1995 ◽  
Vol 182 (6) ◽  
pp. 1785-1792 ◽  
Author(s):  
P Jeannin ◽  
Y Delneste ◽  
S Lecoanet-Henchoz ◽  
J F Gauchat ◽  
P Life ◽  
...  

N-Acetyl-L-cysteine (NAC) is an antioxidant precursor of intracellular glutathione (GSH), usually given in human as a mucolytic agent. In vitro, NAC and GSH have been shown to act on T cells by increasing interleukin (IL) 2 production, synthesis and turnover of IL-2 receptors, proliferation, cytotoxic properties, and resistance to apoptosis. We report here that NAC and GSH decrease in a dose-dependent manner human IL-4 production by stimulated peripheral blood T cells and by T helper (Th) 0- and Th2-like T cell clones. This effect was associated with a decrease in IL-4 messenger RNA transcription. In contrast, NAC and GSH had no effect on interferon gamma and increased IL-2 production and T cell proliferation. A functional consequence was the capacity of NAC and GSH to selectively decrease in a dose-dependent manner IL-4-induced immunoglobulin (Ig) E and IgG4 production by human peripheral blood mononuclear cells. Interestingly, NAC and GSH also acted directly on purified tonsillar B cells by decreasing the mature epsilon messenger RNA, hence decreasing IgE production. In contrast, IgA and IgM production were not affected. At the same time, B cell proliferation was increased in a dose-dependent manner. Not all antioxidants tested but only SH-bearing molecules mimicked these properties. Finally, when given orally to mice, NAC decreased both IgE and IgG1 antibody responses to ovalbumin. These results demonstrate that NAC, GSH, and other thiols may control the production of both the Th2-derived cytokine IL-4 and IL-4-induced Ig in vitro and in vivo.


Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 717
Author(s):  
Heejin Jo ◽  
Hyunjung Baek ◽  
Seon-Young Park ◽  
Bonhyuk Goo ◽  
Woo-Sang Jung ◽  
...  

Bee venom phospholipase A2 (bvPLA2) has been reported to have therapeutic effects such as neuroprotection, anti-inflammation, anti-nociception, anti-cancer properties, caused by increasing regulatory T cells (Tregs). The mechanism of Tregs modulation by bvPLA2 has been demonstrated by binding with the mannose receptor, CD206 in experimental models of several diseases. However, it remains unknown whether this mechanism can also be applied in human blood. In this study, we collected peripheral blood samples from healthy donors and analyzed the percentages of monocyte-derived dendritic cells with CD206 (CD206+ DCs) before expansion, the proportion of Tregs, and the subpopulations after expansion treated with bvPLA2 or PBS using flow cytometry and the correlations among them. The percentage of Tregs tended to be higher in the bvPLA2 group than in the control group. There were significant positive correlations between the CD206 population in hPBMC and the proportions of Tregs treated with bvPLA2, especially in the Treg fold change comparing the increase ratio of Tregs in bvPLA2 and in PBS. These findings indicate that bvPLA2 increased the proportion of Tregs in healthy human peripheral blood and the number of CD206+ DCs could be a predictor of the bvPLA2 response of different individuals.


Sign in / Sign up

Export Citation Format

Share Document