Demonstration of HIV-encoded Proteins in Cultured and in Uncultured CD 4 Positive Mononuclear Cells from Hemophilia Patients Employing Monoclonal Antibodies against p 15, p 24, GP 41, GP 120, and Reverse Transcriptase

1987 ◽  
Author(s):  
P Wernet ◽  
E M Scheider ◽  
P Sarin ◽  
P Chandra ◽  
H H Brackmann ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Reverse Transcriptase ◽  
Antigen Processing ◽  
Mononuclear Cells ◽  
Interleukin 2 ◽  
In Vitro Cultivation ◽  
Success Rates ◽  
Culture Techniques ◽  
Gp 120

In the light of the large percentage of hemophilia patients with antibodies to HIV the identification of a specific virus infection in comparison to HIV antibody negative hemophilia patients has reached crucial importance. The low success rates of direct virus culture techniques together with the as yet low AIDS-di-sease rate observed in these patients separate these patients from the other main risk groups. Within this context, we studied the expression of CD3, CD4, CD8, and HLA class II antigens on fixed cells after PHA stimulation and Interleukin 2 propagation as well as on untreated blood mononuclear cells from healthy individuals and from hemophilia patients by fluorescence activated flow cytometry. Monoclonal antibodies thought to be specific for p 15, p 24, GP 41, GP 120, and for reverse transcriptase revealed a certain number of positive cells on all defined subpopulations analysed. From cell specimen of HIV antibody positive hemophilia patients cells with specific HIV antigens could be enriched by in vitro cultivation. Importantly the expression of virus-encoded antigens preceedes a cytopathic effect for several daVs. Current analyses aim at the prognostic relevance of low amounts of such viral HIV proteins selectively detectable by moAbs.directed to either p 24, GP 41, GP 120, and RT. The reliability, high sensitivity and monoclonal antibody dependent specificity of this newly developed method for the demonstration of HIV specific proteins make it applicable also for longitudinal surveys of hemophilia patients to assess a potential state of viremia or virus antigen processing in their mononuclear cells.

scholarly journals Anticancer immunity induced by a synthetic tumor-targeted CD137 agonist

2021 ◽  
Vol 9 (1) ◽  
pp. e001762
Author(s):  
Punit Upadhyaya ◽  
Johanna Lahdenranta ◽  
Kristen Hurov ◽  
Sailaja Battula ◽  
Rachel Dods ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Tumor Antigens ◽  
Immune Cell ◽  
Checkpoint Inhibitors ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Cancer Therapeutics ◽  
Peripheral Blood Mononuclear ◽  
Tnf Superfamily

BackgroundIn contrast to immune checkpoint inhibitors, the use of antibodies as agonists of immune costimulatory receptors as cancer therapeutics has largely failed. We sought to address this problem using a new class of modular synthetic drugs, termed tumor-targeted immune cell agonists (TICAs), based on constrained bicyclic peptides (Bicycles).MethodsPhage libraries displaying Bicycles were panned for binders against tumor necrosis factor (TNF) superfamily receptors CD137 and OX40, and tumor antigens EphA2, Nectin-4 and programmed death ligand 1. The CD137 and OX40 Bicycles were chemically conjugated to tumor antigen Bicycles with different linkers and stoichiometric ratios of binders to obtain a library of low molecular weight TICAs (MW <8 kDa). The TICAs were evaluated in a suite of in vitro and in vivo assays to characterize their pharmacology and mechanism of action.ResultsLinking Bicycles against costimulatory receptors (e.g., CD137) to Bicycles against tumor antigens (e.g., EphA2) created potent agonists that activated the receptors selectively in the presence of tumor cells expressing these antigens. An EphA2/CD137 TICA (BCY12491) efficiently costimulated human peripheral blood mononuclear cells in vitro in the presence of EphA2 expressing tumor cell lines as measured by the increased secretion of interferon γ and interleukin-2. Treatment of C57/Bl6 mice transgenic for the human CD137 extracellular domain (huCD137) bearing EphA2-expressing MC38 tumors with BCY12491 resulted in the infiltration of CD8+ T cells, elimination of tumors and generation of immunological memory. BCY12491 was cleared quickly from the circulation (plasma t1/2 in mice of 1–2 hr), yet intermittent dosing proved effective.ConclusionTumor target-dependent CD137 agonism using a novel chemical approach (TICAs) afforded elimination of tumors with only intermittent dosing suggesting potential for a wide therapeutic index in humans. This work unlocks a new path to effective cancer immunotherapy via agonism of TNF superfamily receptors.

scholarly journals Lymphokine abnormalities in aplastic anemia: implications for the mechanism of action of antithymocyte globulin

Blood ◽  
1985 ◽  
Vol 65 (2) ◽  
pp. 407-413
Author(s):  
P Gascon ◽  
NC Zoumbos ◽  
G Scala ◽  
JY Djeu ◽  
JG Moore ◽  
...  
Keyword(s):  
Aplastic Anemia ◽  
Mechanism Of Action ◽  
Mononuclear Cells ◽  
Interleukin 2 ◽  
Lymphocyte Function ◽  
Normal Range ◽  
Flow Microfluorometry ◽  
Nonadherent Cells ◽  
Hematopoietic Response

Anti-thymocyte globulin (ATG) provides effective therapy for many patients with aplastic anemia, and its mechanism of action has been presumed to be secondary to lymphocytotoxicity. However, our studies of lymphocyte function in aplastic anemia show marked abnormalities of lymphokine production, which ATG may modulate. In 12 of 17 patients with aplastic anemia, interleukin 2 (IL2) production was markedly elevated in vitro (P less than .01 by paired statistical analysis). Expression of the IL2 receptor, or Tac antigen, on peripheral lymphocytes assessed by flow microfluorometry was also increased above the normal range in 11 of 15 cases. Studies of ATG suggested that it might act to stimulate lymphocyte function. In vitro, ATG is a mitogen, as measured by incorporation of 3H-thymidine into blood mononuclear cells; the response of cells to ATG from patients with aplastic anemia was exaggerated in comparison with normals. Cell proliferation was accompanied by production of IL2 to levels that were, in some cases, similar to those obtained with lectin stimulation. Finally, supernatants from lymphocytes cultured in the presence of ATG were able to replace adherent cells in providing growth factors for the support of nonadherent cells in methylcellulose hematopoietic colony assays. These results provide a mechanism for an “immunostimulatory” action of ATG in effecting hematopoietic response in some patients with aplastic anemia.

scholarly journals Generation of human natural killer cells from immature progenitors does not require marrow stromal cells

Blood ◽  
1994 ◽  
Vol 84 (3) ◽  
pp. 841-846 ◽  
Author(s):  
MR Silva ◽  
R Hoffman ◽  
EF Srour ◽  
JL Ascensao
Keyword(s):  
Nk Cells ◽  
Natural Killer ◽  
Mononuclear Cells ◽  
Viral Infections ◽  
Nk Cell ◽  
Interleukin 2 ◽  
Peripheral Blood Mononuclear ◽  
Specific Lysis ◽  
Human Natural Killer Cells

Abstract Human natural killer (NK) cells comprise 10% to 15% of peripheral blood mononuclear cells and have an important role in immune responses against tumors, viral infections, and graft rejection. NK cells originate in bone marrow (BM), but their progenitors and lineage development have not been completely characterized. We studied the generation of NK cells from purified CD34+HLADR- and CD34+HLADR+ BM progenitors and the influence of various cytokines on their production. We show that CD3-CD56+ cytotoxic NK cells can develop from both progenitors populations when interleukin-2 (IL-2) is present in an in vitro suspension culture system containing IL-1 alpha and stem cell factor. Up to 83.8% and 98.6% CD3-CD56+ cells were detected in CD34+HLADR- and CD34+DR+ cultures, respectively, after 5 weeks of culture; significant numbers of NK cells were first detected after 2 weeks. Cytotoxic activity paralleled NK cell numbers; up to 70% specific lysis at an effector:target ratio of 10:1 was observed at 5 weeks. IL-7 also triggered development of CD3-CD56+ cells from these immature progenitors (up to 24% and 55% appeared in CD34+HLADR- and CD34+HLADR+ cultures, respectively). Our data suggest that BM stromas are not necessary for NK cell development and that IL-2 remains essential for this lineage development and differentiation.

scholarly journals The proliferative response of B cell chronic lymphocytic leukemia to interleukin 2: functional characterization of the interleukin 2 membrane receptors

Blood ◽  
1987 ◽  
Vol 69 (6) ◽  
pp. 1667-1673 ◽  
Author(s):  
I Touw ◽  
L Dorssers ◽  
B Lowenberg
Keyword(s):  
Monoclonal Antibodies ◽  
Chronic Lymphocytic Leukemia ◽  
B Cell ◽  
Functional Characterization ◽  
Interleukin 2 ◽  
Lymphocytic Leukemia ◽  
Membrane Receptors ◽  
Thymidine Uptake ◽  
Cell Chronic Lymphocytic Leukemia

Abstract To determine the growth properties of B cell chronic lymphocytic leukemia (B CLL) and to identify possible abnormalities thereof, we examined the in vitro action of interleukin 2 (IL2) in four patients. Using radiolabeled IL2 and monoclonal antibodies reactive with IL2 membrane receptors we show that CLL cells, after their activation in vitro, express IL2 receptors of a high- as well as a low-affinity type, exactly as has been reported for normal T and B blasts. In three of the four reported cases, CLL proliferation (measured with 3H-thymidine incorporation) depended on the addition of phytohemagglutinin (PHA) to activate the cells and IL2 (optimal concentration, 10 to 100 U IL2/mL). In contrast, the cells of the fourth case of CLL (CLL-4) proliferated in an autonomous fashion, ie, without a need for PHA and IL2 in culture. Specific blocking of the IL2-binding sites with anti-IL2 receptor monoclonal antibodies almost completely inhibited the proliferation of these cells, which indicated that functional IL2 receptors were required for the autonomous proliferation. The demonstration of low concentrations of IL2 activity in the culture medium conditioned by the cells suggests that endogenous IL2 had been responsible for the spontaneous 3H-thymidine uptake by the CLL cells of patient 4. However, we were unable to extract IL2 mRNA from the cells (neither fresh nor after various in vitro incubations) in quantities detectable by Northern blot analysis that would prove that the CLL cells of patient 4 were actively synthesizing IL2 during culture. Thus, individual cases of B CLL are subject to variable growth regulation involving functional IL2 receptors on the cell surface: after activation with PHA the cells respond to exogenous IL2 in a fashion similar to normal B lymphocytes, or the cells are stimulated by endogenous IL2 (or an IL2-like activity) and do not require activation with PHA.

scholarly journals Anti-lymphocyte globulin stimulates normal human T cells to proliferate and to release lymphokines in vitro. A study at the clonal level

Blood ◽  
1988 ◽  
Vol 72 (3) ◽  
pp. 956-963
Author(s):  
GC Barbano ◽  
A Schenone ◽  
S Roncella ◽  
R Ghio ◽  
A Corcione ◽  
...  
Keyword(s):  
T Cells ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
Interleukin 2 ◽  
Suppressor Cells ◽  
Peripheral Blood Mononuclear ◽  
Gm Csf ◽  
Recombinant Interleukin 2 ◽  
Macrophage Colony

Abstract Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic- suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty- eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL- 2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.

scholarly journals Cytokine Production in Cell Culture by Peripheral Blood Mononuclear Cells from Immunocompetent Hosts

1998 ◽  
Vol 5 (1) ◽  
pp. 78-81 ◽  
Author(s):  
Rohit K. Katial ◽  
Doris Sachanandani ◽  
Carolyn Pinney ◽  
Michael M. Lieberman
Keyword(s):  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Interleukin 2 ◽  
Pokeweed Mitogen ◽  
Peripheral Blood Mononuclear ◽  
Necrosis Factor Alpha ◽  
Blood Mononuclear Cells ◽  
Factor Alpha

ABSTRACT The production of interleukin 2 (IL-2) gamma interferon, IL-4, tumor necrosis factor alpha (TNF-α), TNF-β, IL-5, and IL-10 in vitro by peripheral blood mononuclear cells cultured from healthy immunocompetent subjects after mitogen stimulation was determined. The mitogens used were concanavalin A, phytohemagglutinin, pokeweed mitogen, and Staphylococcus aureus Cowen. The results obtained provide a normal range for the production of these cytokines under specified conditions in vitro.

scholarly journals Effect of Lamivudine on the Plasma and Intracellular Pharmacokinetics of Apricitabine, a Novel Nucleoside Reverse Transcriptase Inhibitor, in Healthy Volunteers

2007 ◽  
Vol 51 (8) ◽  
pp. 2943-2947 ◽  
Author(s):  
T. Holdich ◽  
L. A. Shiveley ◽  
J. Sawyer
Keyword(s):  
Reverse Transcriptase ◽  
Healthy Volunteers ◽  
Peripheral Blood Mononuclear Cells ◽  
Peripheral Blood ◽  
Mononuclear Cells ◽  
Transcriptase Inhibitor ◽  
Peripheral Blood Mononuclear ◽  
Blood Mononuclear Cells ◽  
Reverse Transcriptase Inhibitor

ABSTRACT Apricitabine is a novel deoxycytidine analog reverse transcriptase inhibitor. In vitro apricitabine competes with other deoxycytidine analogues for intracellular phosphorylation mediated by deoxycytidine kinase. The topic of this study, the effect of concomitant administration of apricitabine and lamivudine on the plasma and intracellular pharmacokinetics of the two compounds, was investigated in healthy volunteers. Participants (n = 21; age, 18 to 30 years) received apricitabine at 600 mg twice daily, lamivudine at 300 mg once daily, and the two treatments in combination for 4 days each in random order. Plasma, urine, and intracellular pharmacokinetics were assessed on day 4 of each treatment period. Apricitabine was rapidly absorbed after oral administration, with peak concentrations being attained after a mean of 1.76 h. Coadministration with lamivudine had no significant effect on the plasma and urine pharmacokinetics of apricitabine. However, the formation of apricitabine triphosphate in peripheral blood mononuclear cells was markedly reduced after the coadministration of apricitabine and lamivudine than after the administration of apricitabine alone: the area under the concentration-time curve from 0 to 12 h for apricitabine triphosphate during combination treatment was ca. 15% of that seen after the administration of apricitabine alone. In contrast, apricitabine had no effect on the plasma pharmacokinetics of lamivudine or on the formation of lamivudine triphosphate in peripheral blood mononuclear cells. These results are consistent with in vitro findings that lamivudine inhibits the intracellular phosphorylation of apricitabine. In conjunction with similar in vitro observations for emtricitabine and apricitabine, these results suggest that apricitabine should not be coadministered with other deoxycytidine analogues for the treatment of human immunodeficiency virus infection.

Interleukin-2 (hrIL2) Primed T cells display Reduced Alloproliferative Capacity In Vitro Due To Induction Of FOXP3+ Regulatory Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5433-5433
Author(s):  
Dimitra Kokkinou ◽  
Panagiota Stamou ◽  
Angeliki Vittoraki ◽  
Anne-Lise De Lastic ◽  
Spyros Chondropoulos ◽  
...  
Keyword(s):  
T Cells ◽  
Low Dose ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Interleukin 2 ◽  
Regulatory Cells ◽  
Transplant Tolerance ◽  
Immune Exhaustion ◽  
The Impact

Abstract Introduction Prophylactic donor lymphocyte infusions (pDLI) after allogeneic transplantation contribute to immune restoration and reduce viral infections. Furthermore, we have recently shown that pDLI in patients with high risk leukemia significantly reduces the relapse rate, however, they were associated with a relatively high incidence of Graft versus Host Disease (GvHD)(BBMT 2013;19:75-81). Strategies to minimize GvHD without compromising the effect of pDLI against leukemia are needed. IL2 plays dual role in immune responses, contributing to both the generation of effector T cells and the maintenance of regulatory T cells (Tregs). Recently, low dose interleukin-2 (IL-2) therapy has been advanced as a potential immune modulator able to modulate the immune response to aid transplant tolerance and to suppress GvHD through expansion of Tregs (N Engl J Med. 2011; 2055-66). We investigated the impact of priming DLI with low dose IL2 on the proliferative responses to allo-stimulation in vitro. Methods CD3+ T cells purified from healthy individuals by MACS negative selection were primed (p-T cells) or unprimed (np-T cells), with or without (control) 100 U/ml hrIL2 (Proleukin, Novartis) for 7 days. Composition of T-cell cultures was analyzed by flow cytometry for: a) the percentage of T regulatory cells (CD4+/CD25high/Foxp3+/Helios+, b) their differentiation (CD28/CD27), c) their immune exhaustion (Programmed cell death 1, PD1). In vitro alloproliferative capacity of the p-T cells was analyzed with CFSE cell proliferation assay by using them as responder cells in mixed lymphocyte cultures (MLC), with irradiated allo-PB mononuclear cells as stimulators. Results In vitro priming of T-cells with IL-2 (p-T cells) in contrast to np-T or control cells: 1) increase the numbers of CD4+CD25highFoxp3+/Helios+ cells (n=8, 3.3%±0.7 mean±SEM vs 1.01%±0.22, p=0.004 και 1.4%±0.42, p=0.006). Increased levels of Foxp3 expression was also confirmed by Real Time PCR (n=2,1.25AU±0.15 vs 0.29AU±0.04, p=0.028 και 0.26AU±0.07, p=0.024). 2) did not affect the proportion of CD28+/CD27+ non late-differentiated cells (n=3, 60%±0.15 vs61%±0.04, p=0.91 και 59%±0.08, p=0.024). 3) did not cause immune exhaustion through PD1 expression (n=6, 13.3%±1.9 vs 8.1%±2.1, p=0.76, και 14%±2.2, p=0.68). 4) significantly decreases their response rate to allo-stimulus in MLC (n=8, 45%±0.5 vs65%±0.2, p=0.006 και 64%±0.2, p=0.008). The p-T cells regained their alloproliferative capacity after FACS-sorting removal of CD4+/CD25high Tregs. Conclusions Our results show that ex vivo priming of T cells with low dose of IL-2 reduces their in vitro alloproliferative capacity. This reduction is not due to late differentiation or immune – exhaustion of T cells but to selective induction of Foxp3+ cells with immunomodulatory properties in the culture. It remains to be seen whether IL2-primed DLI is safe and effective in transplant patients. Disclosures: No relevant conflicts of interest to declare.

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