Preoperative Mobilization of Circulating Dendritic Cells by Flt3 Ligand Administration to Patients With Metastatic Colon Cancer

2000 ◽  
Vol 18 (23) ◽  
pp. 3883-3893 ◽  
Author(s):  
Michael A. Morse ◽  
Smita Nair ◽  
Monica Fernandez-Casal ◽  
Yuping Deng ◽  
Michelle St Peter ◽  
...  

PURPOSE: To evaluate preoperative dendritic cell (DC) mobilization and tumor infiltration after administration of Flt3 ligand (Flt3L) to patients with metastatic colon cancer. PATIENTS AND METHODS: Twelve patients with colon cancer metastatic to the liver or lung received Flt3L (20 μg/kg/d subcutaneously for 14 days for one to three cycles at monthly intervals) before attempted metastasectomy. The number and phenotype of DCs mobilized into peripheral-blood mononuclear cells (PBMCs) were evaluated by flow cytometry. After surgical resection, metastatic tumor tissue was evaluated for DC infiltration. In vivo immune responses to recall antigens were measured. RESULTS: After Flt3L administration, on average, the total number of leukocytes in the peripheral blood increased from 5.9 ± 1.0 × 103/mm3 to 11.2 ± 3.8 × 103/mm3 (mean ± SD, P = .0001). The percentage of CD11c+CD14− DCs in PBMCs increased from 2.4% ± 1.8% to 8.8% ± 4.7% (P = .004). Delayed-type hypersensitivity (DTH) responses to recall antigens (Candida, mumps, and tetanus) showed marginally significant increases in reactivity after Flt3L administration (P = .06, P = .03, and P = .08, respectively). An increase in the number of DCs was observed at the periphery of the tumors of patients who received Flt3L compared with those of patients who had not. CONCLUSION: Flt3L is capable of mobilizing DCs into the peripheral blood of patients with metastatic colon cancer and may be associated with increases in DC infiltration in the peritumoral regions. Flt3L mobilization is associated with a trend toward increased DTH responses to recall antigens in vivo. The use of Flt3L to increase circulating DCs for cancer immunotherapy should be considered.

2003 ◽  
Vol 47 (4) ◽  
pp. 1233-1240 ◽  
Author(s):  
Fatih M. Uckun ◽  
Chun-Lin Chen ◽  
Peter Samuel ◽  
Sharon Pendergrass ◽  
T. K. Venkatachalam ◽  
...  

ABSTRACT Here we report the antiretroviral activity of the experimental nucleoside reverse transcriptase inhibitor (NRTI) compound stampidine in cats chronically infected with feline immunodeficiency virus (FIV). Notably, a single oral bolus dose of 50 or 100 mg of stampidine per kg resulted in a transient ≥1-log decrease in the FIV load of circulating peripheral blood mononuclear cells in five of six FIV-infected cats and no side effects. A 4-week stampidine treatment course with twice-daily administration of hard gelatin capsules containing 25 to 100 mg of stampidine per kg was also very well tolerated by cats at cumulative dose levels as high as 8.4 g/kg and exhibited a dose-dependent antiretroviral effect. One of three cats treated at the 25-mg/kg dose level, three of three cats treated at the 50-mg/kg dose level, and three of three cats treated at the 100-mg/kg dose level (but none of three control cats treated with placebo pills) showed a therapeutic response, as evidenced by a ≥1-log reduction in the FIV load in peripheral blood mononuclear cells within 2 weeks. The previously documented in vitro and in vivo antiretroviral activity of stampidine against primary clinical human immunodeficiency virus type 1 isolates with genotypic and/or phenotypic NRTI resistance, together with its favorable animal toxicity profile, pharmacokinetics, and in vivo antiretroviral activity in FIV-infected cats, warrants further development of this promising new NRTI compound.


2001 ◽  
Vol 75 (19) ◽  
pp. 9328-9338 ◽  
Author(s):  
Lennart Holterman ◽  
Rob Dubbes ◽  
James Mullins ◽  
Gerald Learn ◽  
Henk Niphuis ◽  
...  

ABSTRACT End-stage simian immunodeficiency virus (SIV) isolates are suggested to be the most fit of the evolved virulent variants that precipitate the progression to AIDS. To determine if there were common characteristics of end-stage variants which emerge from accelerated cases of AIDS, a molecular clone was derived directly from serum following in vivo selection of a highly virulent SIV isolate obtained by serial end-stage passage in rhesus monkeys (Macaca mulatta). This dominant variant caused a marked cytopathic effect and replicated to very high levels in activated but not resting peripheral blood lymphocytes. Furthermore, although this clone infected but did not replicate to detectable levels in rhesus monocyte-derived macrophages, these cells were able to transmit infection to autologous T cells upon contact. Interestingly, although at low doses this end-stage variant did not use any of the known coreceptors except CCR5, it was able to infect and replicate in human peripheral blood mononuclear cells homozygous for the Δ32 deletion of CCR5, suggesting the use of a novel coreceptor. It represents the first pathogenic molecular clone of SIV derived from viral RNA in serum and provides evidence that not only the genetic but also the biological characteristics acquired by highly fit late-stage disease variants may be distinct in different hosts.


2020 ◽  
Vol 94 (19) ◽  
Author(s):  
Maria Paola Pisano ◽  
Olivier Tabone ◽  
Maxime Bodinier ◽  
Nicole Grandi ◽  
Julien Textoris ◽  
...  

ABSTRACT Human endogenous retroviruses (HERVs) and mammalian apparent long terminal repeat (LTR) retrotransposons (MaLRs) are retroviral sequences that integrated into germ line cells millions of years ago. Transcripts of these LTR retrotransposons are present in several tissues, and their expression is modulated in pathological conditions, although their function remains often far from being understood. Here, we focused on the HERV/MaLR expression and modulation in a scenario of immune system activation. We used a public data set of human peripheral blood mononuclear cells (PBMCs) RNA-Seq from 15 healthy participants to a clinical trial before and after exposure to lipopolysaccharide (LPS), for which we established an RNA-Seq workflow for the identification of expressed and modulated cellular genes and LTR retrotransposon elements. IMPORTANCE We described the HERV and MaLR transcriptome in PBMCs, finding that about 8.4% of the LTR retrotransposon loci were expressed and identifying the betaretrovirus-like HERVs as those with the highest percentage of expressed loci. We found 4,607 HERV and MaLR loci that were modulated as a result of in vivo stimulation with LPS. The HERV-H group showed the highest number of differentially expressed most intact proviruses. We characterized the HERV and MaLR loci as differentially expressed, checking their genomic context of insertion and observing a general colocalization with genes that are involved and modulated in the immune response, as a consequence of LPS stimulation. The analyses of HERV and MaLR expression and modulation show that these LTR retrotransposons are expressed in PBMCs and regulated in inflammatory settings. The similar regulation of HERVs/MaLRs and genes after LPS stimulation suggests possible interactions of LTR retrotransposons and the immune host response.


2018 ◽  
Vol 23 (6) ◽  
pp. 509-517 ◽  
Author(s):  
Anna J. Boland ◽  
Nisha Gangadharan ◽  
Pierce Kavanagh ◽  
Linda Hemeryck ◽  
Jennifer Kieran ◽  
...  

Statins are mainstream therapy in the treatment and prevention of cardiovascular disease through inhibitory effects on cholesterol synthesis. However, statins’ beneficial effects in cardiovascular disease may also be attributable to their role as anti-inflammatory mediators. Here, we investigated the effects of simvastatin treatment on expression levels of interleukin (IL) 1β in both patient with hyperlipidemia and healthy human peripheral blood mononuclear cells (PBMCs) using cholesterol crystals (CC), a cardiovascular pathogenic stimulus for activation of the NOD-like receptor pyrin domain–containing protein 3 (NLRP3) inflammasome. Cholesterol crystal-induced NLRP3 inflammasome activation was used to trigger maturation and release of IL-1β in PBMCs. Specifically, isolated PBMCs from patients with hyperlipidemia at baseline and following 8 weeks of in vivo treatment with simvastatin (10-20 mg) daily were stimulated with lipopolysaccharide (LPS; 100 ng/mL) for 3 hours to induce proIL-Iβ expression followed by CC (2 mg/mL) stimulation for further 18 hours to activate the NLRP3 inflammasome complex to induce maturation/activation of IL-1β. Peripheral blood mononuclear cells were also isolated from healthy donors and stimulated in vitro with simvastatin (50, 25, 5, and 2 µmol/L) prior to stimulation with LPS and CC as described above. The effects of simvastatin treatment on levels of IL-1β expression were determined by enzyme-linked immunosorbent assay and western blot. Both in vitro and in vivo treatments with simvastatin led to a significant reduction in the levels of expression of IL-1β in response to stimulation with CC. Simvastatin inhibits the expression and activation of IL-1β induced by CC in PBMCs, which may contribute to its protective role in patients with cardiovascular disease.


Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1595-1603 ◽  
Author(s):  
K Welte ◽  
CA Keever ◽  
J Levick ◽  
MA Bonilla ◽  
VJ Merluzzi ◽  
...  

Abstract The ability of peripheral blood mononuclear cells (PBMC) to produce and respond to interleukin-2 (IL-2) was evaluated in 50 recipients of HLA- identical bone marrow (BM) depleted of mature T cells by soybean agglutination and E rosetting (SBA-E-BM). In contrast to our previous findings in recipients of unfractionated marrow, during weeks 3 to 7 post-SBA-E-BM transplantation (BMT), PBMC from the majority of patients spontaneously released IL-2 into the culture medium. This IL-2 was not produced by Leu-11+ natural killer cells, which were found to be predominant in the circulation at this time, but by T11+, T3+, Ia antigen-bearing T cells. The IL-2 production could be enhanced by coculture with host PBMC frozen before transplant but not by stimulation with mitogenic amounts of OKT3 antibody, thus suggesting an in vivo activation of donor T cells or their precursors by host tissue. Spontaneous IL-2 production was inversely proportional to the number of circulating peripheral blood lymphocytes and ceased after 7 to 8 weeks post-SBA-E-BMT in most of the patients. In patients whose cells had ceased to produce IL-2 spontaneously or never produced this cytokine, neither coculture with host cells nor stimulation with OKT3 antibody thereafter induced IL-2 release through the first year posttransplant. Proliferative responses to exogenous IL-2 after stimulation with OKT3 antibody remained abnormal for up to 6 months post-SBA-E-BMT, unlike the responses of PBMC from recipients of conventional BM, which responded normally by 1 month post-BMT. However, the upregulation of IL- 2 receptor expression by exogenous IL-2 was found to be comparable to normal controls when tested as early as 3 weeks post-SBA-E-BMT. Therefore, the immunologic recovery of proliferative responses to IL-2 and the appearance of cells regulating in vivo activation of T cells appear to be more delayed in patients receiving T cell-depleted BMT. Similar to patients receiving conventional BMT, however, the ability to produce IL-2 after mitogenic stimulation remains depressed for up to 1 year after transplantation.


Pteridines ◽  
2013 ◽  
Vol 24 (3) ◽  
pp. 237-243
Author(s):  
Sebastian Schroecksnadel ◽  
Elena-Sophia Ledjeff ◽  
Johanna Gostner ◽  
Christiana Winkler ◽  
Katharina Kurz ◽  
...  

AbstractIn vitro, large amounts of neopterin are released from human monocyte-derived macrophages and dendritic cells primarily upon stimulation with Th1-type cytokine interferon-γ (IFN-γ). IFN-γ also induces the enzyme indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan (TRP) to form kynurenine (KYN). IDO-mediated TRP catabolism is very effective in suppressing the proliferation of T lymphocytes as well as of pathogens in vitro and in vivo. In this study, we investigated whether exogenously added neopterin may influence IDO activity in resting and in stimulated peripheral blood mononuclear cells (PBMC). PBMC were isolated from healthy donors, and neopterin was added in a concentration range from 0.01 to 50 μmol/L. After 30 min, PBMC were stimulated or not with 10 μg/mL of mitogen phytohemagglutinin (PHA). After 48 h, culture supernatants were collected, KYN and TRP concentrations were measured by high-performance liquid chromatography, and the ratio of KYN vs. TRP was calculated as an estimate of IDO activity. Spontaneous as well as PHA-induced TRP breakdown was suppressed by exogenously added neopterin in a dose-dependent way; the lowest active concentration of neopterin was <100 nmol/L. As neopterin concentrations in the nanomolar range are commonly observed in patients suffering from infections, sepsis, or uremia, our results suggest that neopterin formation might also serve as a feedback mechanism to slow down TRP degradation in vivo.


Sign in / Sign up

Export Citation Format

Share Document